RESEARCH DESIGNS AND STANDARD ORGANISATION … SPEC(1).pdf · Control and Relay Panel for Protection System for 50 Hz AC traction substations parallel operation on 25 kV Side. TI/SPC/PSI/PROTCT/4050

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RESEARCH DESIGNS AND STANDARD ORGANISATION

SPECIFICATION

FOR

HOT DIP ZINC GALVANISATION OF STEEL MAST,

(ROLLED & FABRICATED)

TUBES AND FITTINGS USED ON 25KV AC OHE

No. ETI / OHE / 13 (4 / 84)

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SPECIFICATION NO.ETI/OHE/13(4/84)

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS RESEARCH DESIGNS & STANDARDS ORGANISATION

MANAK NAGAR, LUCKNOW – 226011.

SPECIFICATION

FOR

HOT DIP ZINC GALVANIZATION OF STEEL

MAST, (ROLLED & FABRICATED)TUBES

AND FITTINGS USED ON 25 KV AC OHE

Printed November, 1984.

ISSUED BY

TRACTION INSTALLATION DIRECTORATE RESEARCH DESIGNS & STANDARDS ORGANISATION


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Specifications for equipment that are attached with the bid document. S.No. Title of Specification Specification No. Page No.

1. Hot dip zinc galvanization of Steel

masts (rolled & fabricated) tubes and fittings used on 25 kV AC OHE

ETI/OHE/13(4/84) with A & C Slip No.1, 2 & 3 or latest.

4 - 18

2. Solid Core Cylinderical Post Insulator for 110 kV.

ETI/OHE/64 (10/88) with A & C Slip No.1 or latest..

19 - 30

3. 25 kV AC single pole & Double pole isolators for Railway electrification

ETI/OHE/16(1/94) with A & C Slip No.1 & 2 or latest..

31 – 64

4. 110 kV Double Pole Isolator ETI/PSI/122 (3/89) with A & C Slip No.1 or latest..

65 – 92

5. Solid core porcelain insulators for 25 kV AC 50 Hz. Single Phase overhead Traction lines.

ETI/OHE/15(9/91) with A & C Slip No.1, 2, 3, 4 & 5 or latest..

93 - 155

6. 220 kV or 132 KV or 66 kV or 25 Kv Potential transformers.

TI/SPC/PSI/PTs/0990 with A & C Slip No. 1, 2 & 3 or latest..

156 - 190

7. 25 kV Drop out fuse switch and operating pole.

ETI/PSI/14(1/86) with A & C Slip No.1 or latest..

191 - 204

8. 25 kV / 240 V, 5 KVA, 10 KVA & 50 KVA, 50 Hz Single phase, oil filled Auxilliary transformers.

ETI/PSI/15(08/2003) or latest.

205 - 238

9. 110 kV Lightning Arrester ETI/PSI/137 (8/89) with A&C Slip No.1, 2,3,4 & 5

239 – 269

10. Metal Oxide gapless type lightening arrestor for use on 25 KV side of Rlys., traction sub-stations and switching stations.

ETI/PSI/71 Rev.5(1/87) with A&C Slip No.1, 2,3,4 & 5 or latest.

270 – 297

11. Current Transformer, 220 kV or 132 kV or 110 kV or 66 kV

ETI / PSI / 117 / (7 / 88) with Correction Slip No.1 to 7 or latest.

298 – 333

12. 25 KV AC 50 Hz, Single phase, Oil filled Current transformers with CT ratio of (i) 1000-500/5A & (ii) 1500-750/5 A

ETI/PSI/90 (6/95) with A&C Slip No.1 to 4 or latest..

334– 367

13. 30 MVA, 110/27 KV Single Phase TI/SPC/PSI/30/TRN1050 or 368 - 446

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Traction Power Transformer.

latest.

14. Earthing of power supply installation for 25 KV AC, 50 Hz. Single phase Traction system.

ETI/PSI/120(2/91) with A&C Slip No.1 or latest..

447- 461

15. Low Maintenance Lead Acid 40 AH & 200 AH Cells for Traction Distribution System.

RDSO/PE/SPEC/TL/0040-2003 (Rev-0) or latest.

462 – 485

16. Charger for 110 V, 40 AH & 110V, 200 AH Maintenance Free, Sealed, Lead Acid Battery.

ETI/PSI/158(08/96) or latest. 486- 503

17. Outdoor Circuit Breaker for Railway AC Traction Substations.

TI/SPC/PSI/CB/0000 with AC Slip No.1 & 2 or latest..

504- 569

18. Control and Relay Panel for Protection System for 50 Hz AC traction substations parallel operation on 25 kV Side.

TI/SPC/PSI/PROTCT/4050 or latest.

570 - 645

Note : Drawings indicated in the specifications are in the CD attached with the bid documents.

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Specification No. ETI/OHE/13 (4/84)

Specification for Hot Dip Zinc Galvanization of Steel Mast, (Rolled & Fabricated) Tubes & Fittings used on 25 kV AC OHE.

1. SCOPE 1.1 This standard specifies the requirement of zinc coating on rolled / fabricated masts,

tubes and fittings applied by hot dip galvanizing and the criteria for sampling and inspection of such galvanized members.

1.2 This supersedes RDSO Specification No. ETI/OHE/13 (9/82) issued in September

1982 and No. ETI/OHE/13 (11/83) issued provisionally in November, 1983. 2. PREFERENCE SPECIFICATIONS

In preparation of this specification, assistance of the following Indian Standard and other specifications has been taken.

(i) IS : 4759-1979 : Specification for Hot Dip Zinc Coatings on

Structural Steel and other allied Products. (ii) IS : 209-1979 : Specification for zinc. (iii) IS : 2629-1966 : Recommended Practice for Hot Dip

Galvanizing of Iron and Steel. (iv) IS : 6158-1971 : Recommended Practice for Safe-guarding

against Embrittlement of Hot Dip Galvanized Iron & Steel Product.

(v) IS : 2633-1972 : Method of Testing Uniformity of Coating on

Zinc Coated Articles.

(vi) IS : 6745-1972 : Method for Determination of weight of Zinc Coating on Zinc coated iron and steel articles (with amendment No. 1).

(vii) ASTM A-123 : Spec. for Zinc (Hot Galvanized) Coatings on

(1978) Products Fabricated from Rolled, Pressed and Forged Steel Shapes, Plates, Bars and Strips.

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3. GENERAL REQUIREMENTS 3.1 QUALITY OF ZINC : Zinc conforming to at least grade Zn 99.95 specified in IS :

209-1979 shall be used for the purpose of galvanizing. 3.2 BASE METAL : The steels and castings shall be in accordance with clause 2 of IS :

6158-1971. Where steel is supplied by the fabricator, it is the responsibility of the fabricator to select suitable steel which will withstand normal galvanizing operation without embrittlement.

The edges of tightly contacting surfaces should be completely sealed by welding. The residue of coated electrodes should be removed, prior to pickling, by brushing, chipping or sand blasting.

3.3 SURFACE PREPARATION : Surface shall be cleaned and prepared as per clause 4

of IS: 2629-1966. Malleable iron castings shall be shot and grit blasted before galvanizing.

3.4 GALVANISING : The members shall be galvanized in accordance with the practice

contained in the IS : 2629-1966 unless otherwise specified in the succeeding paragraphs.

4. COATING REQUIREMENTS 4.1 MASS OF ZINC COATING : Minimum average mass of zinc coating on different

kinds of articles shall be as under :- Class of Material Environment where

used Minimum average weight of zinc coating (g/m2)

Rolled steel masts, angles, channels and members fabricated therefrom, steel forgings.

Suburban and lightly polluted area.

610

-do-

Marine and chemically polluted areas.

1,000

Malleable iron castings.

Suburban and lightly polluted area.

610

-do-

Marine and chemically polluted areas.

1,000

Structural tubes all 610

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Note : Articles galvanized with 1000 g/m2 zinc coatings shall be identified by a band of green paint by the galvaniser.

4.2 FREEDOM FROM DEFECTS : The zinc coatings shall be uniform, adherent,

reasonably smooth and free from imperfections such as flux ash and dross inclusions, bare patches, black spots, pimples, lumpiness and runs, rust stains, bulky white deposits and blisters, etc. These terms have been defined in IS : 2629-1966 which (duly amended wherever necessary) are given at Appendix ‘A’.

4.3 STEEL EMBRITTLEMENT : The design of the product and the selection of steel,

wherever steel is to be supplied by fabricator, for its suitability to withstand normal galvanizing operations without embrittlement or the method of fabrication shall be the responsibility of the fabricator. Recommended precautions to properly design, fabricate and prepare the material for galvanizing to prevent embrittlement shall be as per IS : 6158-1971.

5. TESTS. 5.1 TYPE TESTS

(a) Visual Inspection (Clause 7.1) (b) Adhesion of coating (Clause 7.2) (c) Uniformity of coating (Clause 7.3) (d) Mass of zinc coating (Clause 7.4)

Each test shall be conducted on three samples.

5.2 ACCEPTANCE TESTS

(a) Visual Inspection (Clause 7.1) (b) Adhesion of coating (Clause 7.2) (c) Uniformity of coating (Clause 7.3) (d) Mass of zinc coating (Clause 7.4)

5.3 ROUTINE TESTS

(a) Visual Inspection (Clause 7.1) 6. SCALE OF SAMPLING AND CRITERIA FOR CONFORMITY. 6.1 LOT : All the materials of the same type and the same steel, whose coating

characteristics are intended to be uniform, shall be grouped together to constitute a lot. A lot shall not consist of more than one shift’s production or 100 nos. whichever is lower.

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Samples shall be taken from each bath for test. Where the galvanizing is done without the presence of Purchaser, the manufacturer may prepare lots consisting of the articles of the same type and material and galvanized in the same bath. If there are more than one bath, separate lots shall be prepared for each bath.

6.2 SCALE OF SAMPLING : Samples in accordance with TABLE 1 shall be taken, at

random, from each lot for tests. TABLE 1

Scale of Sampling. --------------------------------------------------------------------------------------------------- Lot size Sample size Permissible no. of defective Units --------------------------------------------------------------------------------------------------- Up to 25 3 0 26 – 50 5 0 51 – 100 8 0 --------------------------------------------------------------------------------------------------- 6.2.1 For materials of inconvenient lengths such as OHE masts and from which it is not

possible to cut a specimen for coating characteristic tests, two test pieces of same cross section and not less than 90 cms length shall be galvanized in the same bath along with the masts for each lot upto 100 masts. In such case, the visual test shall be conducted on the main piece and the tests for the adhesion, uniformity and thickness of coating shall be conducted on the test piece.

6.3 The samples selected in accordance with Table 1 above shall be subjected to the

visual inspection (clause 7.1).

If any sample fails to conform to the requirement, the lot shall be rejected. The galvaniser, however, may segregate the good pieces of the lot and submit them once again for inspection.

6.4 If the lot inspected for visual inspection, passes the test, 3 samples for coating characteristics (Clause 6.5) shall be taken from the samples, which were subjected to the visual tests. In case of masts and other long articles, these tests would be conducted on test specimen cut from 90 cm long test pieces galvanized in accordance with Clause 6.2.1.

6.5 Each of the 3 samples will be subjected to test for adhesion, uniformity, mass of zinc

coating. Should any sample fail in any test, six more samples shall be taken from the lot and all the 3 tests repeated. Should any sample fail in the retest, the lot shall be rejected. If it is not possible to take six samples for the test, the lot shall be rejected.

6.6 The material in a lot which has been rejected may be stripped and re-galvanized and

submitted for inspection and tests.

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7. TEST METHODS 7.1 VISUAL INSPECTION : The material shall be inspected visually to observe that it is

smooth, reasonably bright, continuous and free from such imperfections as flux/ash/dross inclusions, bare patches, black spots, pimples, lumpiness runs, rust stains, bulky white deposits and blisters. The stains of flux, usually white in colour, shall not be regarded as flux intrusions (See Appendix ‘A’).

7.2 ADHESION OF GALVANISED COATING : 7.2.1 Coating shall withstand the knife tests as prescribed in IS : 2629-1966. When cut or

pried into, such as with a stout knife applied with considerable pressure, in a manner tending to remove a portion of the coating, it shall only be possible to remove small particles of the coating; and it shall not be possible to peel any portion of the coating so as to expose iron or steel underneath.

7.2.2 On articles fabricated from angles, channels, beams and rolled sections of 8 mm or

more thickness, the adhesion may, alternatively, be tested by pivoted hammer tests as per IS : 2629-1966. This test is not suitable for curved and round surfaces.

7.3 UNIFORMITY OF GALVANISED COATING : 7.3.1 On small articles, which can be conveniently handled the uniformity of the coating

shall be determined by Preece Test in accordance with IS : 2633-1966 by dipping the whole article in the copper sulphate solution. For sheets, strips and other fabricated articles a 10 cm x 10 cm specimen may be cut for tests. For tubes, 100 mm long piece shall be cut from each end of the product, after discarding 300 mm length from the end. The article shall withstand 5 dips of one minute each.

7.3.2 For long articles, such as masts, etc., measurement of coating thickness at a number

of places by magnetic method (Clause 7.4.4) shall be taken as a uniformity test.

Note : The Preece Test is primarily meant for articles where surface is mechanically scrapped or wiped after dip in the galvanizing baths, such as tubes, wires, etc.

7.4 MASS OF GALVANISED COATING : 7.4.1 The average mass of galvanized coating shall be determined by any one of the

following methods as agreed between the purchaser and the galvaniser before the tests.

7.4.2 Mass before and after galvanizing : The mass of coating may be determined by

weighing the article before and after galvanizing, subtracting the first mass from the second and dividing the result by the coated surface area. The first mass shall be

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determined after pickling, rinsing and drying; and the second after cooling to the ambient temperature.

7.4.3 Stripping method : In case of materials galvanized without purchasers’ inspection,

average mass of coating shall be determined by stripping the entire article in accordance with IS : 6745-1972 (See Appendix ‘B’). If the surface area of the entire article cannot be measured easily or if the article is inconveniently large, a specimen of 100 sq. cm. area may be cut from each of the three samples ( 90 cm long test-piece in case of masts) and stripped.

7.4.4 Magnetic thickness gauge method : 7.4.4.1 For large products such as poles, towers, structural shapes and castings the average

weight of the coating shall be determined by a magnetic thickness gauge. 7.4.4.2 Before making the measurement the gauge shall be calibrated by measuring the

thickness of zinc coating on a test panel and comparing the measured value with the value obtained by stripping method on the same piece.

7.4.4.3 In case of masts etc. readings shall be taken along the length at 100 mm interval and

in approximate centre of the flange and then averaged to give a single figure for thickness of coating. For castings etc. at least 5 readings may be taken at convenient locations nearly in the centre. Thickness, in micro-meters, when multiplied by 7.047 would give the average mass of zinc coating (g/m2). Three articles in each lot of upto 100 shall be tested in this manner. Thickness shall not be less than the minimum value specified in Clause 4.1.

8. RECTIFICATION OF DAMAGE 8.1 Normally all fabrication work in the case of galvanized articles shall be completed

prior to galvanizing. If, for any reason, fabrication such as cutting, drilling or welding has to be undertaken after galvanizing, protection of metal exposed as a result of fabrication and rectification of damaged galvanized areas shall be done in accordance with either the following methods or any other method approved by the Purchaser.

8.2 USE OF ZINC BASED SOLDERS : The surface to be protected, or the surface

where galvanizing has been damaged, shall be cleaned and any oxides removed with a weak acid solution and a wire brush. The surface shall be thoroughly washed with water to make it free from any traces of acid. The cleaned area shall be heated with a welding torch and rubbed with white salammoniac. A piece of zinc stick or rod 5-10 mm diameter of high purity shall be melted on this area and spread out with a heated piece of salammoniac. The areas shall then be washed down by water and lightly wire brushed. The workmanship shall be such that the finished surface is smooth and non-porous.

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8.3 USE OF ZINC RICH PAINTS : The damaged surface after cleaning, as mentioned in

para 7.2 shall be painted with two or more coats of zinc rich primer followed by a finishing coat of a zinc rich paint as per the painting schedule recommended by the manufacturers. It is to be ensured that the dry film thickness of zinc rich primer shall not be less than the average thickness of the galvanized coating. The complete painting system i.e. zinc rich primer with the finishing zinc rich paint for this purpose shall be produced from a source of repute and approved by the Purchaser.

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Specification No. ETI/OHE/13 (4/84) APPENDIX “A” (Cl. 4.2)

DEFECTS, THEIR CAUSES AND REMEDIAL MEASURES Defects Causes Recommended actions Ground for rejection Paint grease or oil residues Check cleaning practices

Bare spots Scale or rust residues Check pickling practices

Yes, if bare spots are bigger than 8 mm dia. or 8 mm diagonal.

Residual welding slag

Blast-clean wells; avoid coated rods

Breakdown of preflux coating

Check preflux and drying conditions

Aluminium content of bath too high

Regulate aluminium additions

Rolling defects in basic steel Check steel supply Article in contact during

galvanizing. Keep articles separated.

General roughness

Analysis or original surface condition of steel.

Check steel supply.

Over-pickling Reduce pickling use inhibitor

No

High galvanizing temperature or long immersion time or both

Adjust galvanizing conditions.

Pimples Entrapped dross particles Avoid agitation of dross layer; check carry over of pickle salt.

No, unless dross contamination is heavy

Lumpiness and runs (uneven drainage)

Withdrawal speed too high Remove work slowly

No.

Cold galvanizing bath. Increase temperature. Delayed run-off from seams, joints, bolt holes, etc.

Remove work slowly.

Article in contact during withdrawal.

Flux inclusions

Stale flux burnt on during dipping.

Refresh or renew flux blanket.

Yes. Surface residues on steel. Check steel preparation. Flux picked up from top of bath.

Skim before withdrawal.

Ash inclusion

Ash burnt on during dipping.

Skim bath before dipping.

Yes, if in gross lumps.

Ash picked up from top of bath.

Skim before withdrawal.

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Black spots Includes flux particles from flux ‘dusting’.

Confine fluxing to top of bath.

Yes.

Dirt smuts, splash marks. Check storage conditions. No.

Dull grey coating (all alloy, no free zinc).

Steel composition (high sili-con, phosphorous or carbon) severe cold work.

Check steel supply for composition order to adjust for galvanizing.

No.

Slow cooling after galvani-sing.

Avoid hot stacking quench.

Release of absorbed hydro-gen during solidification of coating.

Avoid over pickling; use inhibitor.

Weeping of acid etc. from seams and folds.

Check product design and fabrication.

Rust stains Storage near rusty material. Check storage condition. No. Bulky white deposit (wet storage stain, white rust).

Confinement of close packed articles under damp conditions.

Storage dry well-ventilated conditions, separate articles with spacer.

No.

Packing of articles while damp.

Dry before packing; include desic cant.

Blisters

Expansion of entrapped hydrogen and moisture in flaws.

Check steel quality

Yes, if general. Driving off of hydrogen absorbed during pickling.

Use shot blast instead of pickle; check steel supply.

Improper malleabilising (for malleable iron castings only)

Check malleabilising practice.

Tiny blisters

Effect sometimes observed on quenched work notably malleable castings. May be caused by gas evolved from the work resulting from absorbed hydrogen or break-down of combined carbon near surface.

Use shot blast instead of pickle. Check malleabilising treatment. Should have no combined carbon near surface of casting.

Yes, if blistering is generally wide spread.

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APPENDIX “B”

STRIPPING METHOD

(Extracted from IS : 6745-1972) Cleaning of test piece : The test pieces shall be washed with solvent naptha, trichloro ethylene or any other suitable organic solvent, then with alcohol and finally dried thoroughly. Stripping Solutions : Dissolve 20 g of antimony trioxide (Sb2O3) or 32 g of antimony trichloride (Sb Cl3) in 1000 ml of concentrated hydrochloric acid (specific gravity 1.1). Immediately before tests, prepare the stripping solution by adding 5 ml of the solution prepared under clause B-2.1 to 100 ml of concentrated hydrochloric acid (specific gravity 1.16). Mix well. Procedure – Weigh the cleaned test specimen whose mass is less than 200 g nearest to 0.01 g; for test piece whose mass is between 300 to 1000 g to the nearest 0.1 g; and for test specimen of over 1000 g to the nearest 0.5 g. After weighing immerse each test piece singly in test solution prepared as per clause B-2.2 and allow to remain there until the violent evolution of hydrogen and only a few bubbles are being evolved. This requires about 15 to 30 seconds. The mass of zinc coating (in g/m2) of surface may be calculated as per the following formula : M1 – M2 M = ----------------- x 106 A Where, M = mass of zinc coating, in g/m2, of surface. M1 = original mass, in g, of test piece. M2 = mass in g, of stripped test piece, and A = coated area of the test piece, in mm2.

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Correction Slip No. 1 (May 1986) to RDSO Specification No. ETI/OHE/13 (4/84) for

Hot Dip Zinc Galvanization of Steel Mast, (Rolled & Fabricated) Tubes & Fittings used on 25 kV AC OHE.

1. Clause 6.1 shall be revised as under :

6.1 LOT : All the material of the same type in a coating bath whose characteristics are intended to be uniform shall be grouped together to constitute a lot.

6.1.1 Sample shall be taken from each bath and tested for conformity of coating.

2. Table 1 under clause 6.2 shall be revised as under :

TABLE 1

Scale of Sampling.

--------------------------------------------------------------------------------------------------- Lot size Sample size Permissible no. of defective Units --------------------------------------------------------------------------------------------------- Up to 25 3 0 26 – 50 5 0 51 – 100 8 0 101 and above. 13 1 ---------------------------------------------------------------------------------------------------

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Corrigendum Slip No. 2 (4/90) to RDSO Specification No. ETI/OHE/13 (4/84)

for Hot Dip Zinc Galvanization of Steel Mast, (Rolled & Fabricated)

Tubes & Fittings used on 25 kV AC OHE.

1. Appendix B 1.1 Clause B-1, 1st line, Read

‘trichloro ethylene’ in place of ‘trichloro ethylen’. 1.2 Clause B-2, Read ‘Stripping Solution’ in place of ‘Stripping solutions’. 1.3 Clause B-2.1, Read ‘Hydrochloric Acid (Specific Gravity 1.16)’ in place of ‘Hydrochloric Acid (Specific Acid 1.12)’. 1.4 Clause B-3, Line No. 3, Read ‘Clause B-2.1’ in place of ‘Clause B-2.2’. 1.5 Clause B-3, Insert the word ‘ceases’ in last line of the clause between ‘hydrogen and ‘and’.

.

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Addendum / Corrigendum Slip No. 3 (4/90) to RDSO

Specification No. ETI/OHE/13 (4/84) for

Hot Dip Zinc Galvanization of Steel Mast, (Rolled & Fabricated) Tubes & Fittings used on 25 kV AC OHE.

1. Clause 2

Add new item as SN (viii) below the para. viii) ASTM : A 153 - Specification of zinc coating (Hot-dip)

(1982) on Iron and Steel hardware. 2. Clause 2

SN (i) Read “IS : 4759 – 1984” in place of “IS : 4759 – 1979”. 3. Clause 4.1, Delete last line “(Structural ------------ 610) and add the following in the

respective columns :

Steel Components less than 5 mm thick all 460 Structural Tubes all 425”.

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SPECIFICATION

FOR

SOLID CORE CYLINDERICAL POST INSULATOR FOR 110 kV

No. ETI / OHE / 64 (10/88)

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SPECIFICATION NO.ETI/OHE/64(10/88)

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS RESEARCH DESIGNS & STANDARDS ORGANISATION


SPECIFICATION

FOR

SOLID CORE SYLINDERICAL POST

INSULATOR FOR 110 kV

ISSUED BY



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GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

RESEARCH DESIGN AND STANDARDS ORGANISATION MANAK NAGAR

LUCKNOW – 226 011


SPECIFICATION FOR SOLID CORE CYLINDRICAL POST INSULATORS FOR SYSTEMS WITH NOMINAL VOLTAGES OF 220 kV, 132 kV, 110 kV AND 66 kV.

1.0 SCOPE : 1.1 This specification applies to out-door type solid core cylindrical post insulators for a

nominal system voltage of 220 kV/ 132 kV/ 110 kV/ 66 kV for use in isolators (disconnectors) or bus bar or fuse supports in un-attended Railway traction substations in any part of India.

1.2 This supersedes specification No. ETI/OHE/64 (6/87) “Solid core post insulators, 220

kV”. 2.0 GOVERNING SPECIFICATION : 2.1 The insulator shall unless otherwise specified conform to I.S.:2544-1973 “Porcelain

post insulators for system with nominal voltages greater than 1000 volts” and I.S.:5350 (Part II) – 1973 “Dimensions of indoor and outdoor porcelain post insulators and post insulator units for systems with nominal voltage greater than 1000 V – Part II Outdoor cylindrical post insulators” which shall be applied in the manner altered, amended or supplemented by the subsequent clauses of this specification.

2.2 In the preparation of this specification assistance has been derived from the

following:

(i) IEC:168-1979 Tests on indoor and outdoor post insulators of ceramic material or glass for systems with nominal voltages greater than 1000 V.

(ii) IEC:276-1979 Dimensions on indoor and outdoor post

insulators and post insulator units for systems with nominal voltages greater than 1000 V.

(iii) IEC:815-1986 Guide for the selection of insulators in

respect of polluted conditions. (iv) JIS-C-3802-1964 Permissible limits of visual defects for

insulating porcelains.

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(v) IS:2108-1977 Black heart malleable iron castings.

(vi) ETI/OHE/13 (4/84) Specification for hot dipzinc galvanisation of R.D.S.O. of steel masts (rolled & fabricated), Tubes

and fittings used on 25 kV AC OHE.

(vii) ETI/OHE/15 (11/83) Specification for solid core insulators for of R.D.S.O. 25 kV single phase 50 Hz overhead traction

lines. 3.0 GENERAL REQUIREMENTS : 3.1 The insulator shall be of solid core construction. The porcelain shall be sound, free

from defects, thoroughly vitrified and smoothly glazed and should be preferably manufactured from alumnia and shall not engage directly with metal fittings. The glaze shall uniformly cover all the exposed porcelain of the insulator and be brown in colour. It shall be suitable for use in medium / heavily polluted atmospheres subjected to dust, smoke and effluents from chemical plants, marine and saline atmospheres.

3.2 The solid core cylindrical post insulators would be subjected to vibrations on account

of trains running on nearby railway tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 to 70 ms lies in the range of 30 to 150 microns at present with the instantaneous peak going upto 350 microns.

3.3 The physical characteristics of the insulator shall be :-

For nominal voltage of 66 kV 110 kV 132 kV 220 kV (i) Overall height in mm 770±1 1200±1 1500±2.5 2300±3.5 (ii) Maximum diameter of the insulating part in mm 195 210 270 300 (iii) Top metal fitting pitch circle diameter in mm 127 127 127 127 (iv) Bottom metal fitting pitch circle diameter 127 127 127 200 (v) Minimum creepage distance in mm. 1810 3075 3625 6125

3.4 The fixing arrangements shall be in accordance with Clause 6 of IS: 5350 (Pt-II) -1973.

3.5 The caps of the insulator shall be of malleable cast in conforming to Grade BM:340

of IS:2108-1977. All ferrous parts shall be hot dipped galvanised in accordance with

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Research Design and Standards Organisation specification no. ETI/OHE/13 (4/84) and weight of zinc coating shall be not less than 1000 gm/ square meter.

3.6 Caps of the insulator shall normally be so sealed on to porcelain with portland cement

as not to cause fractures loosening by expansion or contraction. 3.7 The shed profile of the insulator shall conform to the parameters laid down in

IEC:815. 3.8 The maximum values for the tolerances of parallel eccentricity and angular deviation

shall not exceed the value specified in the second edition of IEC Publication 273-1979, when measured in accordance with the directions contained in Appendix A of the second edition of IEC Publication 168-1979.

3.9 The 220 kV insulator shall consist of a stack of not more than 2 units. 4.0 TEST VOLTAGES : 4.1 The test voltages for the insulator shall be as under:

For nominal voltage of 66 kV 110 kV 132 kV 220 kV (i) Visible discharge test 53 kV 88 kV 106 kV 176 kV (ii) Wet one minute power frequency withstand voltage (rms) 160 kV 230 kV 275 kV 460 kV (iii) Impulse voltage withstand value 350 kVp 550 kVp 650 kVp 1050 kVp

4.1 The power frequency voltage shall be expressed as peak value divided by 1.414. The

impulse voltage shall be expressed as peak value. 4.2 The visible discharge tests voltage, wet one minute power frequency withstand

voltage (rms) and impulse voltage withstand value are referred to the reference atmospheric conditions as given in I.S:2544-1973.

5.0 MECHANICAL LOADS : 5.1 The minimum failing load shall be as under:

For nominal voltage of 66 kV 110 kV 132 kV 220 kV (i) Min failing load in bending 4 kN 4 kN 4 kN 4 kN (ii) Min failing load in tension 35 kN 50 kN 60 kN 80 kN (iii) Min failing load in torsion 2 kNM 3 kNM 3 kNM 3 kNM (iv) Min failing load in compression 70 kN 100 kN 120 kN 160 kN

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5.2 The insulator shall be capable to accept the following minimum bending moment M

at the top metal fixing :

M = 0.5 P h for 66 kV, 110 kV, and 132 kV post insulators M = 0.2 P h for 220 kV post insulators Where P = minimum bending failing load specified in clause – 5.1 and h = total height specified in clause – 3.2 of this specification.

5.3 The successful tenderer shall ensure that a linear progression in the strength of the insulator has been obtained from the above values of M bending moment at the top to P h at the bottom.

Note: This aspect shall be verified during the prototype and acceptance tests.

6.0 TESTS : 6.1 Type Test

The following shall constitute the type tests which shall be conducted as per I.S: 2544-1973 unless otherwise specified at the works of the manufacturer or at reputed testing laboratory in the presence of the Indian Railway’s repersentative/s on the prototype sample. a) Verification of dimensions. b) Visual examination. c) Visible discharge test. d) Impulse voltage withstand test. e) Wet one minute power frequency voltage withstand and wet one minute

power frequency maximum voltage withstand test. f) Temperature cycle test. g) Mechanical strength tests for:

i) Bending ii) Tensile iii) Torsion iv) Compression

h) Porosity test. i) Galvanising test.

6.1.1 The test at (e) above shall be conducted in accordance with Clause-9.7 of Research

Design and Standards Organisation specification No. ETI/OHE/15 (11/83). 6.1.2 The test at (b) above shall be conducted as per JIS-C-3802-1964 “ Permissible limits

of visual defects for insulating porcelains”.

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6.1.3 For the 66 kV, 110 kV and 132 kV insulator, all the above tests shall be conducted on at least three samples individually. For testing the mechanical strength at least three samples should be subjected individually to the bending, torsion, tensile and compression tests, after undergoing temperature cycle test.

6.1.4 For 220 kV insulators, the nature of tests and the number of samples (with the

description) on which the tests shall be conducted are detailed below:

No. of samples Tests of Clause 6.1

i) Three post insulators each consisting of 2 units (a) to (e) and (g)(i) ii) Three top insulator units (g) (ii) to (iv)

iii) 12 top insulator unit and 2 bottom insulator units (f)

iv) Porosity test will be conducted on fragments of three porcelain pieces from the insulator during mechanical strength test.

v) Galvanising test shall be conducted on three caps each of top and bottom insulator broken during the mechanical strength test.

New Clause 6.1.5 Add the following paragraph under this new clause:

Type tests shall be conducted on the first prototype unit manufactured after all the design and drawings have been approved and clearance given by RDSO to this effect.


Before giving the call to RDSO/ the Chief Electrical Engineer for inspection and testing of the prototype of the system, the manufacturer shall submit a detailed test report consisting of schematic circuit diagrams for each of the tests and nature of the test, venue of the test and duration of each test and the total number of days required to complete the test at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, RDSO representative reserves the rights to conduct any additional test(s) besides those specified therein, on any equipment/ sub-system or system so as to test the system to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the manufacturer and RDSO / The Chief Electrical Engineer during the process of testings as

25

regards the type tests and/or the interpretation and acceptability of the type test results, it shall be brought to the notice of the Director General (Traction Installation), RDSO / The Chief Electrical Engineer as the case may be, whose decision shall be final and binding.


Bulk manufacture of the solid core cylindrical post insulators shall be taken up only after specific written approval is given by the Purchaser to the successful tenderer on the basis of the tests conducted on the prototype unit manufactured according to approved design and drawings.

6.1.8 If the prototype of any insulator conforming to this specification has been approved

for earlier supplies to Indian Railways, testing of prototype again for that particular type of insulator may be waived provided that no changes in the design or material(s) used has been made.

6.2 Acceptance Test 6.2.1 The following shall constitute the acceptance tests:

a) Verification of dimensions. b) Temperature cycle test. c) Mechanical strength tests d) Porosity test. e) Galvanisation test.

6.2.2 The number of insulators to be selected for the lot size offered shall be as per table-3 of IS.: 2544-1973. The insulator so selected shall be subjected to tests as detailed below

6.2.2.1 For 66 kV, 110 kV & 132 kV Solid core cylindrical post insulators: Test (a) - On all Samples

Test (b) - On all Samples

Test (c) At least three samples shall be subjected to bending test in the case

of lot size upto 3200 and at least five samples in the case of lot size greater than 3200. The remaining samples shall be divided more or less equally for the other three mechanical tests viz. Torsion, Tensile and Compression.

Test (d) Fragments from all the broken insulator shall be subjected to this test. If any sample fails in this test, the lot shall be rejected.

26

Test (e) On any three samples of MCI caps selected at random after mechanical strength test.

6.2.2.2 For 220 kV Solid core cylindrical post insulators: Test (a) - On all post insulators each consisting of two units.

Test (b) - On all units. Test (c)- At least three bottom units shall be subjected to bending test in the case of

lot size upto 3200 and at least five bottom units in the case of lot size greater than 3200. The bending test shall be conducted on the bottom unit with an extension piece to enable the load to be applied at a distance from the unit corresponding to its position of maximum stressing in the stack.

Remaining tests shall be on top units and they shall be divided more or less equally among the other three mechanical tests viz. Torsion, Tensile and Compression.

Test (d) & (e) - Same as for 66 kV, 110 kV & 132 kV solid core cylindrical post insulators.

6.3 Routine Tests 6.3.1.1 Every insulator shall be subjected to the following routine tests at the

manufacturer’s works as per IS:2544-1973 except where otherwise specified. The manufacturer shall maintain a record of all routine tests conducted and produce the record on demand at the time of inspection for prototype or acceptance testing.

(a) Visual examination (b) Routine mechanical test. (c) Ultrasonic test – This test is to be conducted as per Clause 9.14 of RDSO’s

specification No. ETI/OHE/15 (11/83). (d) Porosity test.

6.4 Acceptance Criteria 6.4.1 Prototype Tests:

The prototype test samples should meet the requirements of all the prototype tests at a time.

6.4.2 Acceptance Tests:

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If the samples fail to meet the requirements of mechanical strength test and porosity test the lot shall be rejected. If the samples fail in test other than mechanical strength and porosity tests, double sampling may be done if the lot is otherwise acceptable. If the samples do not meet the requirement in the double sampling, the lot shall be rejected.

7.0 TECHNICAL DATA AND DRAWINGS : 7.1 The tenderer shall furnish along with his offer, in the performa attached as Annexure

‘A’, the guaranteed performance data and other technical particulars of the insulator. 7.2 The tenderer shall specifically indicate in a statement attached with his offer, his

compliance with each clause and sub-clause of this specification. A separate statement shall be attached with the offer indicating reference to the clauses where the tenderer deviates therefrom together with detailed remarks / justification. If either the statement of compliance or statement of deviations is not attached with offer, it is not likely to be considered. If there are no deviations, a ‘NIL’ statement shall be attached.

New Clause 7.3 Add the following paragraph under this new clause:

The information furnished in Schedule of guaranteed technical performance, data and other particulars shall be complete in all respects. If there is any entry like “shall be furnished later” or blanks are left against any item, the tender is not likely to be considered as such omissions causes delays in finalising the tender.

7.4 The successful tenderers shall be required to submit for approval, the dimensional

drawing as per Indian Railways standard in sizes of 210mm x 297mm or any integral multiple thereof.

7.5 After approval, two copies of reproducible prints shall be supplied to The Director

General (Traction Installation), Research Design and Standards Organisation, Lucknow (India).

8.0 PACKING AND DISPATCH 8.1 Insulator shall be supplied securely packed in wooden cases. Only one insulator unit

shall be packed in a case so as to faciliate manual loading and un-loading. 8.2 In case of the overseas supplies, packing shall be sea-worthy.

28

Specn. ETI/OHE/64 (10/88) Annexure – A.

SCHEDULE OF GUARANTEED PERFORMANCE TECHNICAL AND OTHER PARTICULARS .

S.No

(1 )

Description

( 2 )

Unit of measurement

( 3 )

Value / Information to be furnished by

the bidder. ( 4 )

1. Name of the manufacturer

2. Country of origin 3. Manufacturer’s Type designation 4. Standard specification on which performance data is based 5. Type of porcelain 6. Overall height in mm mm 7. Maximum diameter of shed in mm mm 8. PCD of top metal fitting mm 9. PCD of bottome metal fitting mm 10. Creepage distance (minimum guaranteed) mm 11. Grade & specification of metal fittings 12. Corona initiation voltage …kV (rms) 13. Corona extinction voltage ….kV (rms) 14. Mass of zinc coating of metal fittings g/sq.m 15. Rated voltage kV 16. Visible discharge test voltage kV 17. Dry lightning impulse withstand voltage. kVp 18. Wet one minute power frequency withstand voltage kV (rms) 19. Maximum tolerance of parallelism, eccenticity and angular

deviation

20. Minimum failing load in bending kN 21. Minimum failing load in tension kN 22. Ultimate tensile breaking load …kN 23.

Ultimate breaking torsional moment ….kNm

24.

Frequency of ultrasonic wave …MHz

25. Minimum failing load in torsion kNm 26. Minimum failing load in compression kN 27. Minimum bending moment at top metal fitting kNm 28. Shed profile parameters 29. Progression in bending strength kNm 30. Ultimate breaking bending load …kN 31. Speed of propagation of ultrasonic wave obtained …m/s 32.

Weight of unit …Kg

29

SEPTEMBER 1989

Addendum / Corrigendum Slip No.1 to Specification No.ETI / OHE/64 (10/88) for Solid core Cylindrical Post Insulator for 110 kV. ******** New Clause 6.1.5 - Add the following paragraph under this new Clause.

Type test shall be conducted on the first prototype unit manufactured after all the design & drawings have been approved and clearance given by RDSO to this effect.

New Clause 6.1.6 - Add the following paragraph under this new clause.

Before giving the call to RDSO/ The Chief Electrical Engineer for inspection and testing of the prototype of the system, the manufacturers shall submit a detailed test report consisting of schematic circuit diagrams for each of the test and nature of the test, venue of the test and duration of each test and the total number of days required to complete the test on one stretch. Once the schedule is approved , the test shall invariably be done accordingly. However, during the process of type testing or even later, RDSO representative reserves the rights to conduct any additional test(s) besides those specified therein, on any equipment/sub system or system so as to test the system to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the manufacturer and RDSO/The Chief Electrical Engineer during the process of testing as regards the type tests and/or the interpretation and acceptability of the type test results, it shall be brought to the notice of the Director General (Traction Installation), RDSO/The Chief Electrical Engineer as the case may be, whose decision shall be final and binding.

New Clause 6.1.7 - Add the following paragraph under this new Clause.

Bulk manufacturer of the solid core cylindrical post insulators shall be taken up only after specific written approval is given by the purchaser to the successful tenderer on the basis of the tests conducted on the prototype unit manufactured according to approved design and drawings.

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RESEARCH DESIGNS AND STANDARDS ORGANISATION

SPECIFICATION FOR

25Kv ac SINGLE POLE AND DOUBLE POLE ISOLATORS FOR RAILWAY

ELECTRIFICATION

No. ETI / OHE / 16 (1 / 94)

31

SPECIFICATION No.ETI/OHE/16 (1/94)


RESEARCH DESIGNS AND STANDARDS ORGANISATION MANAKNAGAR LUCKNOW

Technical Specification For

25kV ac Single Pole and Double Pole Isolators for Railway Electrification

ISSUED BY

TRACTION INSTALLATION DIRECTORATE RESEARCH DESIGNS AND STANDARDS ORGANISATION

LUCKNOW – 226011

32

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS RESEARCH DESIGNS AND STANDARDS ORGANISATION

MANAKNAGAR LUCKNOW

Specification No. ETI / OHE / 16 (1 / 94) SPECIFICATION FOR 25 Kv ac SINGLE POLE AND DOUBLE POLE ISOLATORS

FOR RAILWAY ELECTRIFICATION

1. SCOPE 1.1 This specification applies to single-pole as well as double-pole isolator with earthing

switch for outdoor use in 25 kV a.c. 50 Hz single phase overhead equipment, traction substantions and switching stations. The specification also applies to the operating mechanism of the isolator and earthing switch. The isolator shall be mounted on a mast / structure as required.

1.2 The isolator shall be complete with all parts, fittings and accessories including

mounting frame work and operating mechanism but excluding the insulators, necessary for its efficient operation. All such parts. Fittings and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not. The isolat6or shall be of proven design.

2. GOVERNING SPECIFICATIONS. 2.1 The isolator and earthing switch shall unless otherwise specified herein, conform to

the latest version of the Indian Standards specifications / IEC recommendations / Research Designs and Standards Organisation (RDSO) specifications as indicated below and the Indian Electricity Rules, wherever applicable :

i) IS:1570 (Pt. II) – 1979 - Carbon steels (unalloyed steels).

ii) IS:2071 (Pt. I) – 1974 & (Pt. II) –

1976 - General definitions and test

requirements and test procedures.

iii) IS: 2108 – 1977 - Black heart malleable iron castings.

iv) IS: 2544 – 1973 - Porcelain post insulators for systems with nominal voltage greater than 1000 volts.

v) IS: 5561 – 1970 - Electric power connectors. vi) IS : 7608 – 1975 - Phosphor bronze wires (for general

33

engineering purposes). vii) IS : 7906 – 1975 - Helical compression springs

viii) IS : 9921 – 1985

(Pt. I, II, III & IV) - Alternating current disconnectors

(Isolators) and earthing switches for voltage above 1000v.

ix) IEC : 129 – 1975 - Alternating current disconnectors (Isolators) and earthing switches.

x) ETI / OHE / 13 (4 / 84) - Specification for hot dip zinc coating on steel masts (rolled and fabricated) tubes and fittings used on 25 kV ac OHE.

xi) ETI / OHE / 18 (4 / 84) - Specification for steel and stainless steel bolts, nuts and washers.

xii) ETI / OHE / 64 (10 / 88) - Specification for Solid Core Cylindrical post insulators for system with nominal voltages of 220 kV, 132 kV, 110 kV & 66 kV.

2.2 Any deviation from this specification proposed by the tenderer, calculated to improve

upon the performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of the deviation with justification therefor are furnished. In such a case, the tenderer shall quote according to this specification and deviation, if any, proposed by him shall be quoted as an alternative (s).

In case of any contradiction between the provisions of Indian Standards Specification / recommendations of the IEC and this specification, the latter shall prevail.

3 SERVICE CONDITIONS 3.1 The isolator is intended to be used as outdoor line sectioning switches. The isolator

shall be used in normally polluted atmosphere subject to dust smoke and effluents from chemical plants. It may also be used in coastal areas.

3.2 Environmental conditions: i) Maximum temperature of air in shade - 45 C

ii) Minimum temperature of air in shade - 0 C

iii) Maximum relative humidity - 100%

iv) Annual rain fall - Ranging between 1750mm and

6250 mm

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v) Number of thunderstorm days per annum

- 85 (maximum)

vi) Number of duststorm days per annum

- 120 (maximum)

vii) Maximum wind pressure - 200 kgf / m

viii) Altitude - Not exceeding 1000 m.

The isolator shall be subjected to vibrations on account of trains running on nearby railway tracks. The amplitude of these vibrations, which occur with rapidly varying time periods in the range of 15 to 70 ms, lies in the range of 30 to 150 microns with the instantaneous peak going upto 350 microns. 4. DEFINITIONS 4.1 Isolator.

It is a mechanical switching device which provide, in the open position, an isolating distance between the two contacts in accordance with specified requirements.

An isolator is capable of opening and closing a circuit when either negligible current is broken or made, or when no significant change in the voltage across the terminals at each pole of the disconnector (isolator) occurs. It is also capable of carrying currents under normal circuit conditions and carrying, for a specified time, currents under abnormal conditions such as those of short circuit.

4.2 Earthing Switch.

A mechanical switching device for earthing part of a circuit, capable of withstanding for a specified time currents under abnormal conditions such as those due to short circuit, but is not required to carry current under normal conditions of the circuit.

4.3 Main circuit.

All the conducting parts of an isolator or earthing switch included in the circuit which is designed to close or open.

4.4. Pole.

The portion of an isolator or earthing switch associated exclusively with one electrically-separated conducting path of its main circuit and excluding those portions which provide means of mounting and operating all poles together.

4.5 Closed position

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The position in which the predetermined continuity of the main circuit is secured. 4.6 Open position.

The position in which the predetermined clearance between open contacts in the main circuit is secured.

4.7 Position indicating device.

A device which indicates, at the location of the isolator or earthing switch, whether the contacts of the main circuit are in open or closed position.

4.8 Interlocking device.

A device which makes the operation of the isolator or earthing switch dependent upon the position or operation of one or more other pieces o equipment.

4.9 Ambient temperature.

The temperature determined under prescribed conditions, of the air surrounding the complete switching device (e.g. for enclosed switching devices, it is the air outside the enclosure).

4.10 Operation cycle.

A succession of operations from one position to another and back to the first position through all other operations, if any.

4.11 Dependent Manual Operation.

An operation solely by means of directly applied manual energy, such that the speed and force of the operation are dependent upon the action of the operator.

4.12 Rated value.

A stated value of any one of the characteristic value that serve to define the working conditions for which the isolator or earthing switch is designed and built.

4.13 Normal current.

The current which the main circuit of the isolator is capable of carrying continuously under specified conditions of the use and behavior.

4.14 Short – time withstand current.

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The current that an isolator or the earthing switch can carry in the closed position during a short specified time period under prescribed conditions of the use and behavior.

4.15 Permissible duration of short-circuit current.

The time during which an isolator or earthing switch in the closed position can carry a short-circuit current of specified value.

4.16 Permissible peak withstand current.

The value of peak current that an isolator or earthing switch can withstand in the closed position under prescribed conditions of use and behavior.

4.17 Rated 1 min power frequency withstand voltage.

The r.m.s. value of sinusoidal alternating voltage at power frequency which the insulation of the isolator or earthing switch withstands under specified test conditions.

4.18 Rated impulse withstand voltage.

The peak value of the standard (1.2/50 u s) impulse voltage wave which the insulation of the isolator or earthing switch can withstand under specified test conditions.

4.19 Clearance.

The distance between the conducting parts along a string stretched the shortest way between these conducting parts.

4.20 Clearance between poles.

The clearance between any conducting parts of the adjacent poles. 4.21 Clearance to earth.

The clearance between any conducting parts and any parts which are earthned or intended to be earthed.

4.22 Clearance between open contacts (gap).

The total clearance between the contacts or any conducting parts thereto, of a pole of an isolator or earthing switch in the open position.

4.23 Isolating distance.

37

The clearance between open contacts or any conducting parts connected thereto in a pole of an isolator meeting safety requirements.

5. RATING AND OTHER PARTICULARS i. Type - Manually operated, horizontally

mounted on pole, vertical break type and suitable for outdoor

ii. Number of phases - One

iii. Number of poles - One or two (as specified by the purchaser).

iv. Isolating distance (In air). - 500 mm (min.)

v. Rated voltage - 25 kV (nominal)

vi. Rated current :

i. Type – I - 1250 A

(Isolator used at sectioning and parallelling post & Sub-sectioning and parallelling post)

ii. Type II - 1600 A

(Isolator used at Feeding post & Traction sub-station) vii. Rated frequency. - 50 Hz. +/-3 %

viii. Rated short time - 20 kA

Withstand current (Both for main &

earthing switch - (r.m.s.) for 3 s.

ix. Rated peak withstand current (both for main & earthing switch)

- 50 kA for 3 s.

x. Temperature rise :

The temperature rise of any part of an isolator shall not exceed the maximum temperature rise given below under the conditions specified in the test clauses – 12.5

Nature of parts Temperature in degree celsius

Temperature rise in degree celsium

38

i. Copper contacts in air: bare copper or tinned aluminium alloy

75

35

ii. Terminals of isolators to be connected to external conductors by screws or bolts – bare

90 50

iii. Metal parts acting as springs

The temperature shall not reach a value where the elasticity of the materials is impaired. Fr pure copper the temperature limit is 75 deg. C.

xi. Rated impulse (1.2 / 50 micro – second) withstand voltage:

i. To earth and between. The poles

250 kV (peak)

ii. Across the isolating distance.

290 kV (peak)

xii. Wet power frequency 1 min withstand voltage:

i. To earth 95 kV (r.m.s.)

ii. Across isolating distance

110 kV (r.m.s.)

6. DESIGN CONSTRUCTION AND MOUNTING . 6.1 The support and operating rod insulators shall be of solid core type in accordance

with the latest specification of RDSO viz No. ETI / OHE / 15 and shall be procured, if included in the order, only from the approved manufacturers as per drawings approved by RDSO. Note : The insulators shall be supplied by Railways. The tenderers may, therefore quote rates without insulators.

6.2 The isolator shall be robust in construction and so engineered as to ensure smooth

operation at all times. The isolator, both single and double pole, shall be supplied fully assembled on a suitable rigid frame. For double pole isolators, the cross channels for mounting shall also form part of supply. The support and frame work shall be designed for a wind pressure of 200 kgf/m acting on 150% of the projected area in addition to all other loads. During the opening and operations of the isolator there shall be no shock. There shall also not be a backlash tending to open

39

the isolator after closing, due to the jerk, if any. All poles of the isolator shall required, for the proper alignment of the pole after mounting. All movable joints shall be provided with brass bushes / bearings, which shall be entirely maintenance free.

6.3 The blades of the isolator shall be of electrolytic high conductivity copper tubes of

adequate strength and cross section to IS : 91 (Part V) – 1980 to withstand thermal and bending stresses particularly under short circuit fault conditions.

6.4 Flexible braided copper, where used, shall have corrosion resistant coating such as

tinning or silvering. The connection between the flexible braid and rotating and fixed parts shall be by means of not less than two bolts to prevent any tendency of rotation.

6.5 For reasons of safety, the isolator should be so designed that no dangerous leakage

current can pass from the terminals of one side to any of the terminals of the other side.

6.6 The frame (isolator mounting channel) of each isolator shall be provided with an

earthing terminal for connecting to an earthing conductor having clamping screws, suitable for earth fault conditions. The diameter of the clamping screws shall be not less than 12 mm. The connecting point shall be marked with “Earth” ( ) symbol.

6.7 When installed, the isolator shall be able to bear on terminals the total forces

(including wind load and electrodynamic forces on the attached conductors) related to the application and rating without impairing their reliability or current carrying capacity.

6.8 The isolator shall be constructed so as to permit it being locked both in the open as

well as closed positions. It shall not be possible to lock the isolator in any intermediate position.

6.9 The fixed contacts of isolator shall be of extruded, rolled or drawn copper strips. The

contacts shall be spring loaded. Only nonferrous or stainless steel components shall be used in the contact assembly.

6.10 The springs used in the contact assembly of the isolator shall be or phosphor bronze

conforming to IS : 7608 – 1975. To avoid current passing through the springs, nylon strip of suitable size shall be provided for insulation. The characteristics of the springs shall conform to IS: 7906 (Pt. II) – 1976 and their mechanical properties shall not be affected in any manner on account of rise in temperature during operation.

6.11 Bolts, nuts locknuts and other fasteners of 12 mm dia and less shall be of stainless steel. Fastners of higher size may be made of hot dip galvanised steel. All fasteners shall be procured from approved manufacturers, a list of which may be obtained from Central organisation for Railway Electrification Allahabad. The fasteners shall confirm to RDSO specification No. ETI / OHE / 18.

40

6.12 The mounting arrangement and the operating mechanism shall be such that with the isolators mounted in the working position, the hinge pin of the operating handle is at a height of 1.1 m from ground level. The height of base of the rigid frame referred in clause 6.2 would vary, depending on the type of mast / or structure on which the isolator is mounted. The heights for typical masts / structures are given below.

------------------------------------------------------------------------------------------------------------ Location Height of isolator mounting channel from ground level in mm ---------------------------------------------------------------------------- SP DP ------------------------------------------------------------------------------------------------------------ RSJ / BFB mast. 8310 8160

RSJ with super mast. 9425 9275

R. Portal 9535 9385

N. Portal 9485 9335

O. Portal 9585 9435

Two Track Cantilever 9560 9410

SS, SSP, SP, FP 3262

5425 --

5525 (When busbar height is 5968 mm)

6.13 The isolator shall be supplied with operating pipe in exact length for the particular

mast/structure, the length being obtained from the purchaser for each type of mast/structure.

6.14 The operating pipe shall not have any joint and shall be supplied with four guides

unless otherwise specified in the purchase order. The operating pipe shall be obtained only from approved manufacturers, a list of which may be obtained from Central Organisation for Railway Electrification / Allahabad.

6.15 All Malleable cast iron parts shall be of black heart malleable cast iron grade BM –

340 conforming to IS : 2108 – 1977. 6.16 All ferrous parts shall be hot dip galvanised in accordance with specification No. ETI

/ OHE / 13 (4 / 84). 6.17 The Isolator shall be provided with a terminal pad at each end as shown in Annexure

“B” attached. The terminal pad shall have few holes as indicated for being connected to a terminal connector.

41

6.18 The general arrangement of the isolator shall be as shown in Annexure ‘B’. The

essential dimensions are also indicated in the Annexure ‘B’. 7. OPERATION 7.1 The operating mechanism shall be such that it is possible to fasten the base to which

the operating handle is attached, to either of the two mutually perpendicular vertical faces of the supporting structure on which the isolator is mounted.

7.2 The operating handle of the isolator shall be so designed as to work in the vertical

plane. The isolator shall close when the handle is moved upwards. The free end of moving contact shall be fully housed in the fixed contact when the handle is moved fully upward in which position the isolator can be locked.

7.3 The design of the single pole isolator shall be such as to permit coupling of isolators

for gang operation from a single operating handle. Not more than two single pole isolators are required to be coupled.

7.4 Suitable “OFF” and “ON” plates shall be provided on the operating handle to indicate

when the isolator is open and closes respectively. 7.5 The general arrangement of operating mechanism shall be shown in Annexure “B”. 8. LOCKING 8.1 A bolt type integral lock and / or inter lock, as specified by the purchaser, of approved

type shall be fitted on the isolator to enable the operating handle of the isolator to be locked effectively in the “open” as well as in the “close” position. It shall not be possible to withdraw the key from the integral lock except when the isolator is locked either in the open or in the closed position.

8.2 The operating mechanism shall be so designed as to permit padlocking, in addition to

the integral lock and / or interlock, for locking the operating handle of the isolator both in the open as well as in the closed positions.

8.3 The addition to locking arrangement described in Clause 8.1, the design of operating

mechanism shall permit its operation in a predetermined sequence related to the operation of other switchgear with the help of suitable interlocks.

8.4 The internal mechanism of integral lock and interlock shall be of stainless steel or non

– ferrous material. It shall be of robust construction. The outer housing of the interlock and integral lock shall be chrome plated steel and the construction shall be such that it is not prone to theft. The integral lock and interlock shall be obtained only from the approved manufacturers.

42

8.5 Each lock shall be supplied with two keys.

Key / lock number shall be inscribed on the keys / locks.

9. EARTH CONTACT ASSEMBLY 9.1 The design of the isolator shall be such that it is possible to incorporate an additional

pair of contacts so as to effectively earth the fixed contact of the isolator in open position even at a later date.

9.2 The design of the isolator frame shall permit the provision of the earth contact

assembly without calling for modification to the frame itself. Two holes of 15.5 + 0.5 mm dia shall be provided on the – 0.0 mounting channel for connecting the earthing terminals.

9.3 The earth contact assembly shall be rated for the short time current specified in Clause

5 (viii) & (ix). 10. ARACING HORN 10.1 The single pole isolator shall be provided with arcing horns which shall be of bright

steel to Gr. 20 – C- 8 of IS : 1570 (Pt. II) – 1979. The arcing horns shall make contact before the main contacts close and break contact after the main contacts break.

11. TESTS 11.1 Type tests

Only after all designs and drawings have been approved and clearance given by RDSO / Chief Electrical Engineer to this effect, the manufacturer shall take up the manufacture of the prototype. It is to be clearly understood their any changes to be done in the prototype as required by RDSO/Chief Electrical Engineer shall be done expeditiously. Before giving the call to RDSO / Chief Electrical Engineer for inspection and testing of the prototype, the manufacturer shall submit a detailed test schedule consisting of schematic circuit diagram for each of the test and the nature of the test, venue and duration of each test and the total number of the days required to complete the test at one stretch. Once the schedule is approved, the test shall invariably be done accordingly. However, during the process of type testing or even later, RDSO / Chief Electrical Engineer’s representative reserves the right to conduct any additional test (s) beside those specified herein, on any equipment / sub – system or system so as to test the system to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the manufacturer and RDSO / the Chief Electrical Engineer during the process of testing as regards the type tests and / or the interpretation and acceptability of the type test results, it shall be

43

brought to the notice of the Director General (Traction brought to the notice of the Director General (Traction Installations), RDSO / Chief Electrical Engineer as the case may be whose decision shall be final and binding. The following tests shall be carried out on the prototype unit of the isolator and earthing switch at the works of the manufacturer / sub- contractor or at a reputed testing laboratory, in the presence of RDSO / Chief Electrical Engineer’s representative (s) in accordance with the relevant governing specification and / or as modified or amplified hereunder against each test : i. Visual examination of isolator and its parts ii. Dimensional verification of parts iii. Assmebly and interchangeability iv. Measurement of resistance of main circuit and / earth circuit (before and after

mechanical endurance test v. Temperature rise test (before and after mechanical endurance test) vi. Mechanical endurance test vii. Short time rated current test viii. One minute wet power frequency test across the isolating distance and to earth ix. Impulse voltage withstand test across isolating distance and to earth x. Galvanisation test xi. Chemical analysis of materials – copper contacts, springs, fastners and bushes xii. Physical tests on springs and fasteners and copper strips.

11.1.1 If the electrical clearances viz. The isolating distance clearance of live parts to ground

and the clearance between the two poles are maintained to Annexure ‘B’ and the insulators are supplied by the purchaser, high voltage tests (12.8 and 12.9) may be waived at the discretion of RDSO / CORE / Purchaser.

11.2 Acceptance tests. 11.2.1 For the purposes of acceptance, isolators shall be offered for inspection in lots

containing components for not more than 50 assemblies of same type of isolators. The isolators offered for inspection shall first be routine tested by the manufacturer and defective components removed.

11.2.2 The visual examination and measurement of resistance shall be done on all he

isolators offered for inspection. The defective ones shall be either attended to or removed before further tests are conducted.

11.2.3 The following shall comprise the acceptance test :

i. Visual examination (on every item of the lot) ii. Dimensional verification of parts (on 10% sample of the lot, minimum one

number) iii. Assembly and interchangeability (of minimum 3) iv. Galvanisation test (one sample of each item )

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v. Measurement of resistance (all samples) Note : Number of samples drawn for tests may be increased at the discretion of

RDSO / Chief Electrical Engineer’s representative (inspector) during the inspection.

11.2.4 The inspector may, at his discretion, conduct any or all of the tests (C1, 12, 5) (C1,

12, 11) and (C1, 12, 12) for a particular lot. The manufacturer shall arrange for the test.

11.2.5 Acceptance criteria. 11.2.5.1 If during dimensional verification of parts, assembly and interchangeability, any

component fails to meet the requirement of this specification, twice the number of the same shall be taken and the tests repeated. If the component (s) fail to meet the requirement again, the lot shall be rejected. The manufacturer may sort out the again, the lot shall be rejected. The manufacturer may sort out the defective pieces and offer the lot once again. Should there be any failure in the lot offered once again, the lot shall be rejected totally.

11.2.5.2 If the sample fails to meet the requirements of C1, 12, 10 twice the number of

samples for same component / assembly shall be drawn and subjected to the same test. Should the sample fail in the re-test, the lot of particular component will be rejected. The manufacturer may re-assemble the isolators using new components and offer once again for inspection.

11.2.6 Routine tests. 11.2.6.1 The manufacturer shall carry out the following as routine tests :

i. Visual examination. ii. Dimensional verification of parts. iii. Assembly and interchangeability.

11.2.6.2 The manufacturer shall offer record of the routine tests and acceptance tests

carried out by him to ensure quality of raw materials, to the inspector. Unless these are satisfactory, no acceptance test shall be carried out. Mention of routine tests and acceptance tests carried out by the manufacturer shall be made in the test report and salient extracts reproduced.

12 TEST METHODS 12.1 Visual examination. 12.1.1 All components shall be visually examined to check that they are properly

manufactured, do not have sharp edges and corners, the tubes are not crooked or bent and galvanisation of ferrous components is free from visible defects mentioned in

45

Appendix ‘A’ RDSO specification No. ETI / OHE / 13 latest version. The finish stainless steel fasteners and pins shall be smooth and bright.

12.2 Dimension verification. 12.2.1 The components of the isolators, particularly –

- moving contact blade - the spring of the fixed contact - the housing for fixing contact jaws on the post insulators.

The fixed and moving contact jaws, the operating shaft for the operating pipe and the contacts shall be checked with respect to the approved drawings. The components shall be in accordance with the approved drawings.

12.3 Assembly and interchangeability. 12.3.1 The isolator shall be assembled, using the components picked up at random from

different lots. No adjustments shall be required in any component to enable quick assembly of the isolator. After assembly the isolator shall function smoothly without any adjustments.

12.3.2 The components such as the housing for the fixed and moving contacts, the housing

for the earth contact assembly shall then be interchanged to ensure that the components are fully interchangeable. Fixing of different components shall be without any difficulty and any special adjustment.

12.3.3 The dimensions of the isolator assembly, particularly the following critical ones shall

be verified :

i. Minimum clearance between moving blade and the jaw of the fixed contact at free end when the isolator is open

ii. The clearance between the earth end of the operating rod insulator with both

the live terminals in closed as well as open positions.

iii. The travel of the moving blade with full travel of operating pipe.

iv. The distance between the centres of all the holes of the isolator assembly for fixing it on the masts.

v. When the isolator is in fully closed position, the moving contact shall go home

fully into the fixed contact and no portion shall remain projecting beyond the fixed contact on the upper side. The main contact shall not exert undue pressure on the stopper.

12.4 Measurement of the resistance of the main circuit / earth circuit.

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12.4.1 This measurement is made for comparison between the isolator type tested for

temperature rise and all other isolators of the same type subjected to acceptance tests. 12.4.2 The resistance shall be measured with direct current

A direct current of any convenient value between 100 and rated normal current shall be passed through the main circuit / earthing contact circuit as the case may be and the voltage drop between the two terminals of each pole of the isolator shall be measured to obtain the resistance at the ambjent temperature. All values measured / obtained shall be recorded.

12.4.3 The measurement of resistance shall be made before the temperature rise test. 12.4.4 The test shall also be conducted during acceptance test. The maximum value of

resistance shall not exceed 1.5 times the resistance obtained during type tests or R x T/t,

whichever is lower, where – R = Resistance obtained during type test. T = Permissible temperature rise (35 deg. C) t = Temperature rise obtained during type tests at hottest spot.

12.4.5 For the purpose of the acceptance test, the measurement of resistance may be made

by using micro-ohm meter calibrated to the satisfaction of the inspector. 12.5 Temperature rise test. 12.5.1 The test for temperature rise of main circuit shall be made on a new isolator with

clean contact pieces. The isolator shall be mounted approximately as under usual service conditions, including all normal covers of any part of the isolator, and shall be protected against undue heating or cooling.

12.5.2 Temporary connections to the main circuit shall be such that no appreciable amount

of heat is conducted away from or conveyed to the isolator during the test. In case of doubt the temperature rise of the terminals of the main circuit and at temporary connections at a distance of 1 m from the terminals shall be measured. The difference of temperature shall not exceed 5 deg. C.

12.5.3 The test shall be made with the rated normal current of the isolator (i.e. 1250 A for

isolators for SSP and SP and 1600 A for isolators to be used at FP and TSS) and at rated frequency (50 Hz) + 3%.

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12.5.4 The duration of the test shall be made over a period of time sufficient for the temperature to reach a steady state i.e. when the variation of temperature does not exceed 1 deg. C per hour over three hours.

12.5.5 The temperature of the different parts shall be measured with thermometers,

thermocouples or other suitable means, placed at the hottest accessible spot. The following precautions shall be taken when measuring with thermometers or thermocouples :

i. Thermocouples or the bulbs of thermometers shall be protected against

being cooled from outside during the test. The protected surface area shall, however, be negligible when compared with the cooling surface area of the part under test.

ii. Good heat conductivity between the bulb of the thermometers or

thermocouples and the surface of the part under test shall be insured.

iii. Alcohol thermometers shall used as they are accurate for such purposes.

12.5.6 The time for the whole test may be shortened by preheating the circuit with the higher

value of current. 12.5.7 In case the temperature rise at any part of the isolator exceeds the values specified in

Clauses 5 (x), the isolator shall be deemed to have failed in the test. 12.6 Mechanical endurance test. 12.6.1 The mechanical endurance test shall be conducted in accordance with IS : 9921 (PT

IV) but the number of operating cycles shall be 5000 instead of 1000 as specified therein. The condition of all parts shall be satisfactory after the test. On successful completion, the test shall be continued upto 10000 cycles to determine the weak spots.

12.6.2 For this test, the isolator shall be complete with operating and locking mechanism etc. 12.7 Short time withstand current test. 12.7.1 The test shall be conducted at the current value specified in Clause 5 (viii) for 3 s. 12.7.2 The arrangement for the test as shown in Annexure ‘C’ may be used, both for the

single pole as well as for the double pole isolators and associated earthing switches. The distance x between the earthing terminals of the disconnector and the nearest support of the test connections is equal to three times the distance between pole test connections is equal to three times the distance between pole centres. The distance u and v are as small as possible but not less than y.

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12.7.3 The a.c. component of the test current shall be equal to the a.c. component of the

rated short time withstand current of the isolator or earthing switch. The peak current shall be not less than the rated peak withstand current but shall not exceed it by more than 5% without the consent of the manufacturer.

12.7.4 The value of the test current and its duration shall be such that –

I2

1 . t1 = I2 . t

Where – I1 = r.m.s. component of test current measured in accordance with

Appendix to IS: 9921 (Pt. IV) in A. I = r.m.s. component of specified short-time current in A (20,000 A). t = Specified short – time current duration in seconds (3 s) t1 = Duration of current in s.

Note : This test shall be conducted at Central Power Research Institute. Bangalore only, unless otherwise approved by RDSO.

12.7.5 During the test to prove its capability of carrying the rated peak withstand current and

the rated short time withstand current, the isolator or earthing switch shall not show undue stress. After the test, the isolator or earthing switch shall not show any material deterioration and shall be capable of operating normally.

12.7.6 Visual inspection and no-load operation of the tested isolator or earthing switch are

usually sufficient to check these requirements. 12.7.7 The test may be considered completed successfully if the isolator can be operated

manually after tests. There should be no damage, which may affect its mechanical and electrical performance.

12.7.8 If after the test, there is any doubt about its current carrying capability, temperature

rise test shall be made before the isolator is reconditioned. The value of temperature rise shall not exceed the figure given in Clause 5 (x).

12.8 Wet power frequency voltage withstand test. 12.8.1 The isolator and earthing switch shall be subjected to wet power frequency voltage

withstand test in accordance with IS : 2071 (Pt. I & II).

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12.8.2 The test voltage shall be raised for each test condition to the rated withstand voltage, duly corrected for the ambient atmospheric conditions, specified in C1. 5 (x11) and shall be maintained for 1 min. No disruptive discharge shall take place during the 1 min period.

12.8.3 The wet power frequency voltage withstand test shall be conducted in accordance

with IS : 2071 (Pt. I). However, if the water of prescribed resistivity can not be obtained, water of lower resistivity may be used, provided that the isolator passes the test. The actual value of resistivity of the water and the rate of precipitation (both horizontal) and vertical components) shall be stated in the test report.

12.8.4 The test shall be conducted in following conditions :

i. Between isolator and earth : With the isolator in the closed position, the test voltage shall be applied to one of the 25 kV terminals, the support frame – work and the other pole connected together and earthed.

ii. Across isolating distance : With the isolator in the open position, the test

voltage duly connected for ambient conditions, shall be applied at the moving blade (s) and the other two terminals shall be connected to the earth of the testing transformer. The whole isolator shall be adequately insulated from the ground to prevent possibility of direct flashover. Note : If the order is for both single pole and double pole isolators, these tests would be conducted on a double pole isolator with earthing switch.

12.9 Lightning impulse voltage tests. 12.9.1 If the order is for both single pole and double pole isolators, this test shall be

conducted on a double pole isolator with earth contact assembly. Isolator and earthing switch shall be subjected to dry lightning impulse voltage test, with both positive and negative polarities using standard 1.2 / 50 micro-second lightning impulse according to IS : 2071 (Pt. I).

12.9.2 Impulse voltage test between Isolator and earth with the isolator in closed position

and earthing switch open, 15 consecutive impulses of 250 kV duly corrected for the ambient atmospheric conditions, shall be applied between one terminal and the frame, the other pole being connected to the frame. The isolator shall be considered to have passed the test, if number of disruptive discharges to frame or to the adjacent pole does not exceed two.

12.9.3 Impulse voltage test across isolating distance.

The isolator shall be in the open position. The frame – work shall be adequately insulated from earth so as to prevent any disruptive discharges direct to earth. Lightning impulses of 290 kV duly corrected for ambient conditions shall be applied

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to the moving blade (s). The remaining two terminals shall be connected to the earth. The isolator shall be deemed to have passed the test if there is no disruptive discharge to the opposite terminals.

12.10 Galvanisation test.

12.10.1 In the type test, at least two samples of each type of component which has been

galvanised shall be tested for ensuring that the galvanising done conforms to specification No. ETI/OHE/13 in regard to adherence, uniformity and mass of zinc coating. The mass of zinc coating shall be not less than 610 g/m2.

12.10.2 In the acceptance test, one sample of each type of component which has been

galvanised shall be tested for ensuring that the galvanising done conforms to specification No. ETI/OHE/13 in regard to adherence, uniformity and mass of zinc coating. The mass of zinc coating shall be not less than 610 g/m2.

12.11 Chemical analysis of materials.

12.11.1 The chemical analysis of phosphor bronze springs, copper tube / strips of moving and

fixed contacts and stainless steel fasteners shall be conducted in accordance with IS : 7608, IS : 191 and RDSO specification No. ETI / OHE / 18 as applicable. The material shall conform to the requirements specified.

12.11.2 Physical tests on fasteners shall be conducted in accordance with RDSO

specification No. ETI / OHE / 18. The results shall be in accordance with the requirement laid down in the specification.

12.12 Physical tests on the springs and on copper strips shall be conducted inaccordance with IS : 7906 (Part II) and IS : 1897 respectively.

13.0 BULK MANUFACTURE

13.1 Only after clear written approval of the results of the tests on the prototype is

communicated by RDSO / Chief Electrical Engineer to the manufacturer, shall be take up bulk manufacture of the equipment – which shall be strictly with the same material and process of manufacture as adopted for the prototype. In no circumstances shall material other than those approved in the designs / drawings and / or the prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

13.2 If the prototype of an isolator and / or earthing switch conforming to this specification

has been approved for earlier supplies to Indian Railways, testing of prototype again may be waived. Provided that no changes in the design or materials (s) used or process of manufacture have been made.

13.3 Technical data and drawing.

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13.3.1 The tenderer shall furnish alongwith his offer the guaranteed performance data and

other technical particulars of the equipment in the proforms attached at Annexure ‘A’.

13.3.2 The information furnished in the Schedule of guaranteed technical performance, data and other particulars shall be complete in all respects. If there is any entry like “shall be furnished later” or blanks are left against any item of Schedule of guaranteed particulars, the tender is not likely to be considered as such omissions cause delay in finalising the tender.

13.3.3 Reports of the type tests, if conducted on the similar equipment shall also be

furnished.

13.4 The tenderer shall specifically indicate in a statement attached with his offer, his compliance with each clause and sub-clause of this specification. If any vague remark on any clause or sub-clause of this specification is given by the tenderer then the tender submitted by him is not likely to be considered. A separate deviation statement shall be furnished with the offer drawing attention to the clause (s) where the tenderer seeks deviation giving detailed remarks / justification thereof. If there are no deviations, a ‘NIL’ statement shall be furnished.

13.5 The tenderer shall furnish alongwith tender the following drawings :

i) General arrangement drawings showing the outline dimensions of isolators and earthing switch (whenever provided).

ii) Drawing for support insulators alongwith salient technical particulars. iii) Drawing for operating mechanism of main isolator. iv) Drawing for operating mechanism of earthing switch.

13.6 The manufacturer shall be required to submit the following detailed dimensioned

drawings including drawings already mentioned in clause 8.5 above, as per Railways standards in size of 210 mm x 297 mm or in integral multiple thereof, for approval : i) details of main contacts. ii) details of earthing contacts.

iii) interlocking arrangement.

iv) Castell type integral lock

v) mounting details of isolator.

vi) terminal connector.

vii) Loads exerted by the isolator & earthing switch (wherever provided) for

designing the mounting structure. This drawing should furnish complete information regarding loads and their point of application.

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13.7 After approval, six copies of approved drawings along with two sets of reproducible

prints shall be supplied to each consignee. Two copies of drawings along with one set of reproducible prints shall be supplied to the Director General (TI), Research Design and Standards Organisation, Manaknagar, Lucknow – 226011.

14. INSTALLATION, OPERATION AND COMMISSIONING Twenty sets of installation, operation and maintenance instructions shall be supplied to the Purchaser with every order. Two copies of these instructions shall be supplied to the Director General (TI), RDSO, Lucknow. The information shall necessarily include – i) Procedure for erection and precautions to be taken during the process. ii) The details of maintenance practices to be adopted under normal service

conditions. The number of operations (or the period) after which different parts of isolator and / or earthing switch requires to be specifically attended to shall be indicated.

iii) Procedure for overhauling of isolator and / or earthing switch. iv) Procedure for replacement of parts, like contacts, subject to wear and tear and

deterioration during service.

v) List of spare parts required for 5 years maintenance.

vi) List of special tools required for maintenance / replacement.

vii) Lubrication instructions including type of lubricants and quantity to be used. 15. PACKING AND DESPATCH 15.1 Various components of the isolator and / or earthing switch shall be securely packed

in a proper manner in a wooden crate / box. It shall be ensured that one crate / box does not contain components of more than one complete isolator and / or earthing switch. A detailed packing list with weight and overall dimensions of the crate / box shall be furnished for each crate / box indicating the following : -

------------------------------------------------------------------------------------------------------------ Crate / Box No. Description of each Gross weight Outside component in the in kg. dimensions crate / box of crate / box. ------------------------------------------------------------------------------------------------------------

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15.2 The weight of a crate / box containing all components shall be such that it can be

manually handled conveniently by not more than two persons. 15.3 Necessary instructions for handling and storage shall also be furnished for use at the

receiving end. This specification supersedes Specification No. ETI / OHE / 16 (10 / 86) Rev – 1.

********************************

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Annexure – A

Specification No. ETI / OHE / 16 (1 / 94).

SCHEDULE OF GUARANTEED PERFORMANCE DATA TECHNICAL AND OTHER PARTICULARS.

25 kV a.c. SINGLE POLE ISOLATORS S. No. Description Unit of measurement / data. ----------- -------------------------------------------------- ------------------------- 1. Name of manufacturer 2. Country of origin. 3. Standard specification on which

performance is based. 4. Manufacturer’s type designation. 5. Rated voltage. kV 6. Rated current :

a) Isolator A

b) Earthing switch A 7. Rated frequency Hz. 8. Rated insulation level

a) Rated one minute power frequency wet withstand voltage. i) To earth and between poles kV (rms) ii) Across isolating distance kV (rms) b) Rated one minute power frequency

dry withstand voltage. i) To earch and between poles kV (rms) ii) Across isolating distance kV (rms)

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c) Standard lightning impulse (1.2 / 50 microsecond) withstand voltage – i) To earth and and between poles kVp ii) Across isolating distance kVp

9. Rated short time withstand current

current (for 3 seconds ) – i) Isolator kA (rms) ii) Earthing switch kA (rms)

10. Dynamic peak withstand current :

i) Isolator kAp ii) Earthing switch kAp

11. Maximum temperature rise over an

ambient temperature of 40 deg. C when carrying its rated current. Deg. C.

i) Copper contacts.

ii) Terminal pad of the isolator to be connected to terminal connectors by both. iii) Metal parts acting as spring 12. Breaking capacity of capacitive

current at rated voltage. A 13. Number of poles Number 14. Number of breaks per pole Number 15. Total length of break per pole mm 16. Centre distance between poles mm

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17. Minimum clearance in air

a) Between poles mm b) Between the live part and earth mm c) Between open contacts of the same pole. mm d) Isolating distance mm

18. Contacts

a) Material of the moving contact. b) Material of the fixed contact.

c) Thickness of silver coating. Micron. d) Contact pressure. kg.

19. Operating mechanism.

a) Type b) Can be fitted with power Yes / No

c) Operated device.

d) Height of the operating handle hinge

Pin from ground level. m

d) Weight of the operating mechanism kg 20. Insulator

a) Name of manufacturer. b) Type designation

c) Standard specification on which

Performance is based. IS

d) Number of stack e) Weight of one insulator. kg.

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f) Number of insulators used

i) Support ii) Rotating / operating

g) Wet power frequency withstand Voltage (1 minute). kV (rms)

h) Dry power frequency withstand

Voltage (1 minute). kV (rms) i) Visible discharge test voltage kV j) Impulse withstand voltage kVp

k) Wet power frequency flashover voltage. kV (rms)

l) Dry power frequency flashover

Voltage. kV (rms)

m) Puncture voltage kV (rms) n) Minimum failing load in bending. kN o) Minimum failing load in tension kN p) Minimum failing load in torsion kN q) Minimum failing load in compression kN r) Creepage distance in air mm

s) Shed profile 21. Type of bearings used in the isolator. 22. Type and material of terminals. 23. Total weight

i) Isolator kg

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ii) Earthing switch kg

24. Number of closing and opening

operations, the isolator can perform without deterioration of its contacts.

Additional information 25. Is contact silver plated ? Yes / No 26. Is pad locking arrangement for

operating mechanism box provided? Yes / No 27. Is mounting arrangement for

interlock (s) on isolator operating mechanism provided? Yes / No

28. Is integral lock on earth mechanism

provided? Yes / No 29. Is mounting arrangement for interlock

With associated isolator provided? Yes / No 30. Is mechanical interlocking arrangement

between earthing switch and the isolator provided? Yes / No

31. Is the material of fasteners of 12 mm

dia and below stainless steel? Yes / No 32. Is the material of fasteners above 12

mm dia galvanised stainless steel ? If not, what is it? Yes / No

33. Is frame work for the isolator made

of steel galvanised? Yes / No 34. Two number of earthing studs

provided for - a) Isolator frame Yes / No b) Earthing switch frame Yes / No c) Operating mechanism box Yes / No d) Earthing symbols provided Yes / No

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35. Is height of operating handle hinge pin in earthing switch from ground level 1.1 m? Yes / No

36. Is arrangement for keeping the

operating handle for isolator in the operating mechanism box provided? Yes / No

37. Can the isolator be converted to

motor operated one with minor modification (if yes, sketch to be shown for modification required)? Yes / No

38. Is the operating mechanism box for

the isolator is weather, dust and vermin proof? Yes / No

39. Is Open / Closed indicator provided for –

a) Isolator Yes / No b) Earthing switch Yes / No

40. Is Padlocking provided for –

a) Main rotating shaft of isolator Yes / No b) Operating handle for earthing

switch. Yes / No. c) Lid cover for operating mechanism

box. Yes / No. 41. Are the bearings maintenance

free? Yes / No. ****************************

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Addendum / Corrigendum Slip No. 1 (June 2000) to the technical Specification No. ETI/OHE/16 (1/94) for 25kV, single pole/double pole isolators for ac traction system. S.No

Clause No.

Description

As amended

1 2 3 4 1. 5.0 (vi)

page-6

Rated current Add under the existing entries and read as : i. Type I (a) 1250 A (b) 3150 A (for continuous) [Isolator used at sectioning and paralleling post & sub sectioning and paralleling post] ii. Type II (a) 1600 A (b) 6300 A (for 60 sec.) [Isolator used at feeding post & traction substation]

2. 5.0 (viii) page-6

Rated short-time withstand current. (both for main & earthing switch)

The existing entries may read as : i. 20 kA rms (for 3 sec.) ii. (a) 50 kA rms (for 3 sec.) (b) 100 kA rms (for 1 sec.)

3. 5.0 (ix)

Rated peak withstand current (both for main & earthing switch)

Add under the existing entries : i. 50 kA peak ii. 125 kA peak

4. 11.1 page-12

Type Tests Add a new para after the existing entries : “In the event of the tests not being carried through to completion at one stretch for any reason attributable to the successful tenderer / manufacturer & it is required for the representative of the purchaser / Director General (Traction Installation) Research, Designs & Standards Organization (DG/TI/RDSO), Lucknow to go again or more number of times to the works of the successful tenderer / manufacturer or other place(s) for continuing and / or completing the tests on the prototype(s) of the equipment the successful tenderer / manufacturer shall reimburse to the purchaser, DG/TI/RDSO, Lucknow the cost for the representative having to visit to the works or other place(s) for the tests more than once. The cost as claimed by the purchaser / DG/TI/RDSO, Lucknow shall be paid through a demand draft to the concerned accounts officer of the purchaser / DG/TI/RDSO, Lucknow as shall be advised to the successful tenderer / manufacturer.”

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5. 12.5.3 Page- 16

Temperature rise test.

The existing clause may be read as : “The test shall be made with the rated normal current of the isolator (ie. 1250 A or 3150 A for isolators used at SSP & SP and 1600 A or 6300 A for isolators to be used at FP & TSS) and rated frequency 50 ± 3% Hz.”

6. 13.6 Page 21

Technical data and drawing

Add a new item after the existing entries. “viii. Name & rating plate on the isolator (the rated characteristic shall be in conformity with clause 3.0 of IS : 9921 / part ii).”

7. 13.7 Page 22

Drawing Add in the 3rd line of the existing entries ie. In between “reproducible print” and shall be supplied..” “and on floppy along with hard copy (in ACAD R 14) after final approval of drawings…”

8. 16.0 Page 23

Warranty Add a new clause 16.0 The successful tenderer / manufacturer shall warrant that equipment shall be free from defects and faults in design, material, workmanship & manufacture and of the highest grade consistent with the established and generally accepted standards for the equipment of the type ordered and full conformity with specification and shall operate properly. This warranty shall survive inspection of, payment for and acceptance of the equipment, but shall expire 18 months after the delivery at ultimate destination or 12 months from the date of commissioning and proving test of the equipment at ultimate destination, whichever period expires earlier.

9. Item-9 of Annx.-A Page 25

Rated short time withstand current.

Add after the existing entries. b. Rated short time withstand current (for 1 sec.)

i. Isolators kA rms ii. Earthing switch kA rms.

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Addendum / Corrigendum Slip No.2 (March 2004) to the Technical Specification No..ETI / OHE/16 (1/94) for 25 kV Single Pole /double pole isolators to be used in AC Traction system on Indian Railways. S.No. Clause

No./ Page No.

Description As amended

1. 5.0 (vi)/ Page-6

Rated current The existing entries shall be replaced with following : i) Type 1 : 1250A (Isolator used in OHE and at SP,

SSP). ii) Type II : 1600A (Isolator used at FP & TSS) iii) Type III : 3150A (Used in OHE, during

transition in DC-AC conversion and in 30 MVA traction substation on Mumbai suburban section).

2. 5.0(viii)/ Page-6

Rated short time withstand current(Both for main & earthing switch)

The existing entries shall be replaced with following :” i) 20 kA rms for 3 sec. For type I & Type II isolators. ii) 50 kA rms for 3 sec. For Type III isolator.

3. 5.0(ix)/ Page-6

Rated peak withstand current (Both for main & earthing switch)

The existing entries shall be replaced with following :” i) 50 kA Peak for Type I & Type II isolators. ii) 125 kA peak for Type III isolator

4. 5.0(x)/ Page-7

Temperature rise The existing entries shall be replaced with following :” The Temperature rise of any part of an isolator shall not exceed the maximum temperature rise given below under the conditions specified in the test clause 12.5.

S.No. Name of parts Temperature in ºC

Temperature rise at an ambient temperature not exceeding 40ºC

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RDSO Specification No.ETI / OHE/ 16 (1/94) for 25 kV Isolator SP/DP. The following amendments are made in addition to the addendum and corrigendum slips issued to the specification : S.No. Para No. Amendment 1) In Para 1.2 Delete the words “but excluding the insulators” appearing in line 2 & 3 2) In Para 3.2 ( vii) Substitute “200 kgf/sqm” with “112.5 kgf/sqm” 3) In Para 6.1 Delete words “and shall be procured ……..by RDSO” appearing in lines 2, 3 & 4. Delete the Note under Para 6.1 4) In Para 6.2 In line No.5, substitute “200 kgf/m²” with “112.5 kgf/ m²” 5) In Para 6.13 Delete the words “the length ……..mast/structure” after mast/structure in line 2.

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RESEARCH DESIGNS AND

STANDARDS ORGANISATION

SPECIFICATION

FOR

110KV DOUBLE & TRIPLE POLE ISOLATOR

No. ETI / PSI / 122 (3 / 89)

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SPECIFICATION NO. ETI/PSI/122 (3/89) GOVERNMENT OF INDIA MINISTRY OF RAILWAYS

TECHNICAL SPECIFICATION

FOR

(i) 245 kV (ii) 145 kV (iii)123 kV (iv) 72.5 kV

DOUBLE POLE & TRIPLE POLE ISOLATOR

FOR

RAILWAY TRACTION SUBSTATION.

ISSUED BY TRACTION INSTALLATION DIRECTORATE

RESEARCH DESIGNS AND STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW – 226 011.

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Specification No. ETI/PSI/122 (3/89) 245 kV / 145 kV / 123 kV / 72.5 kV DOUBLE POLE AND TRIPLE POLE ISOLATOR.

1. SCOPE 1.1 This specification applies to outdoor, double pole and triple pole, horizontal, single or

double break type isolator for a nominal system voltage of 220 kV / 132 kV / 110 kV / 66 kV for use in unattended railway traction substations, in any part of India. It supersedes specification Nos. ETI/PSI/88 (4/87), ETI/PSI/20 (6/78), ETI/PSI/20 A (6/79), ETI/PSI/20 B (7/79), ETI/PSI/41 (1/73), ETI/PSI/50 (8/79) and ETI/PSI/50 B (4/80).

1.2 The isolator shall be manually operated, with or without earthing switch as specified by

the Purchaser in the particular tender and shall be complete with all parts, fittings and accessories including insulators, mounting attachments, operating mechanism box, etc. necessary for their efficient operation.

1.3 All such parts, fittings and accessories shall be deemed to be within the scope of this

specification, whether specifically mentioned or not. The isolator shall be of proven design.

2 GOVERNING SPECIFICATIONS 2.1 The isolator shall, unless otherwise specified herein, conform to the latest version of the

Indian Standard Specifications / IEC recommendations / Research, Designs and Standards Organisation (RDSO) specifications as indicated below and the Indian Electricity Rules, wherever applicable:

(i) IS : 1570 (Pt. II) – 1979 - Carbon steels (unalloyed steels). (ii) IS : 2071 (Pt. I) – 1974 - General definitions and test

& (Pt. II) – 1976 requirements and test procedures.

(iii) IS : 2108 – 1977 - Black heart malleable iron castings.

(iv) IS : 2544 – 1973 - Porcelain post insulators for systems with nominal voltage greater than 1000 volts.

(v) IS : 5561 – 1970 - Electric power connectors.

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(vi) IS : 7608 – 1975 - Phosphor bronze wires (for general engineering purposes)

(vii) IS : 7906 – 1975 - Helical compression springs.

(viii) IS : 9921 – 1885 - Alternating current disconnectors (Pt. I, II, III & IV) (Isolators) and earthing switches for

voltage above 1000 V.

(ix) IEC : 129 – 1975 - Alternating current disconnectors (Isolators) and earthing switches.

(x) ETI/OHE/13 (4/84) - Specification for hot dip zinc coating

on steel masts (rolled and fabricated tubes) and fittings used on 25 kV AC OHE.

(xi) ETI/OHE/18 (4/84) - Specification for steel and stainless

steel bolts, nuts and washers.

(xii) ETI/OHE/64 (10/83) - Specification for Solid Core Cylindrical post Insulators for system with nominal voltages of 220 kV, 132 kV, 110 kV & 66 kV.

2.2 Any deviation from this specification proposed by the tenderer, calculated to improve

upon the performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of the deviation with justification thereof are furnished. In such a case, the tenderer shall quote according to this specification and deviation, if any, proposed by him shall be quoted as an alternative (s).

2.3 In case of any contradictions between provisions of Indian Standard Specification /

recommendations of the IEC and this specification, the later shall prevail. 3 SERVICE CONDITIONS 3.1 Environmental Conditions

(i) Maximum temperature of air in shade 45 degree C (ii) Minimum temperature of air in shade 0 degree C (iii) Maximum relative humidity 100% (iv) Annual rainfall Ranging between

1750 to 6250 mm.

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(v) Number of thunder storm days per annum 85 (Max.) (vi) Number of dust-storm days per annum 120 (Max.) (vii) Maximum wind pressure 200 kg/m2

(viii) Altitude Not exceeding

1000 m.

3.2 The isolator would be subjected to vibrations on account of trains running on nearby tracks. The amplitude of these vibrations, which occur with rapidly varying time periods in the range of 15 to 70 ms, lies in the range of 30 to 150 microns with the instantaneous peak going upto 350 microns.

4 TECHNICAL SPECIFICATION 4.1 Rating and other Technical particulars for isolator.

The isolator shall be designed for the following rating and other technical particulars :- --------------------------------------------------------------------------------------------------- S. No. Ratings / Rated System voltages Particulars --------------------------------------------------------------- 72.5 kV 123 kV 145 kV 245 kV (1) (2) (3) (4) (5) (6) --------------------------------------------------------------------------------------------------- i. Type Manually operated, single or double break, upright

mounting with the movement of blade(s) in a horizontal plane, with or without earthing switch and suitable for outdoor installation.

ii. Number of Two or three as specified in the particular Poles specification of tender.

iii. Nominal system 66 kV 110 kV 132 kV 220 kV Voltage

iv. Highest system 72.5 kV 123 kV 145 kV 245 kV Voltage

v. Isolating distance 1200 mm 1800 mm 1800 mm 2800 mm in air (Min.)

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vi. Rated insulation level: (a) Rated one minute power

frequency wet withstand voltage. 1) To earth and 140 kV 230 kV 275 kV 460 kV

between poles (rms) (rms) (rms) (rms)

2) Across isolating 160 kV 265 kV 315 kV 530 kV distance (rms) (rms) (rms) (rms)

(b) Lightning impulse

(1.2/50 micro-second) withstand voltage 1) To earth and 325 kVp 550 kVp 650 kVp 1050 kVp

between poles

2) Across isolating 375 kVp 630 kVp 750 kVp 1200 kVp distance

vii. Rated frequency 50 Hz 50 Hz 50 Hz 50 Hz

± 3 % ± 3 % ± 3 % ± 3 % viii. Rated normal 1250 A 1250 A 1250 A 1250 A

current

ix. Rated short time 31.5 kA 31.5 kA 31.5 kA 31.5 kA withstand current (rms) (rms) (rms) (rms) for one second

x. Dynamic peak of 80 kA 80 kA 63 kA 80 kA the time withstand current.

xi. Maximum temperature rise over an ambient temperature of 40 deg. C when carrying its rated current.

a) Copper contacts 35 35 35 35

Deg. C Deg. C Deg. C Deg. C b) Terminal pad of 50 50 50 50

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the isolator to Deg. C Deg. C Deg. C Deg. C be connected to terminal connectors by bolts

c) Metal parts acting The temperature shall not reach a value where the

as spring elasticity of the metal parts acting as springs gets impaired.

4.2 The isolator shall be capable of breaking capacitive current of busbars, bushings, very

short lengths of overhead lines, cables and no-load current of the transformer. Such currents are not likely to exceed 6 Amps.

4.3 Rating and other Technical particulars for earthing switch.

The earthing switch shall be designed for the following rating and other technical particulars :- --------------------------------------------------------------------------------------------------- S. No. Ratings / Rated System voltages Particulars --------------------------------------------------------------- 72.5 kV 123 kV 145 kV 245 kV (1) (2) (3) (4) (5) (6) --------------------------------------------------------------------------------------------------- i. Type Manually operated, vertically mounted, vertical air

break type and suitable for outdoor installation.

ii. Rated voltage Associated with 245 / 145 / 123 / 72.5 kV isolators, as the case may be.

iii. Rated frequency 50 Hz 50 Hz 50 Hz 50 Hz

± 3 % ± 3 % ± 3 % ± 3 % iv. No. of poles Two or three as specified in the tender. v. Rated short time 31.5 kA 31.5 kA 31.5 kA 31.5 kA withstand current (rms) (rms) (rms) (rms) for one second vi. Dynamic peak of 80 kA 80 kA 63 kA 80 kA the short time withstand current.

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5 TYPE, CONSTRUCTION AND MOUNTING 5.1 Isolator. 5.1.1 The isolator shall be robust in construction and so engineered as to ensure smooth

operation at all times. --------------------------------------------------------------------------------------------------- S. No. Clearance / 72.5 kV 123 kV 145 kV 245 kV Distance ---------------------------------------------------------------------------------------------------

1. Distance between 2000 mm 3000 mm 3000 mm 4500 mm pole centers. --------------------------------------------------------------------------------------------------- 5.1.2 The moving blades shall rotate through 90 degree from their fully closed position to

fully open position, so that the break is distinct and clearly visible from ground level. 5.1.3 The isolator shall be designed to minimize the shock during opening and closing

operations and shall not have a backlash tending to open the isolator after closing due to jerk. The isolator shall be so designed that it can not come off its open / close position by vibrations, shocks or any other means except when specifically operated with the help of its operating handle.

5.1.4 The rotating blade(s) on the moving poles shall operate simultaneously. An

arrangement for necessary adjustment to achieve this feature shall be provided. 5.1.5 Main Contacts

1. The isolator shall have heavy duty self aligning and high pressure contacts of modern design. 2. The contacts of the isolator shall be in the form of reverse loop so that during passage of short circuit current they exert additional pressure on the moving contacts. 3. The blades of the isolator shall be of rotating type at its longitudinal axis by the turn and twist mechanism provided in the moving contact assembly.

4. The moving and fixed contact assemblies shall be so designed as to ensure:-

a) electro dynamic forces withstand ability during short circuit without

any risk of dislodging of moving contact from the fixed contact; b) thermal withstand ability during short circuit;

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c) constant contact pressure even when the live parts of the insulator

stacks are subjected to tensile stress due to linear expansion of connected busbar conductor, either because of temperature variation or strong winds.

d) Wiping and self cleaning action during closing and opening, and

e) Self aligning ensuring smooth closing of the isolator.

5.1.6 Earthing Switch

1. The earthing switch shall be manually operated. 2. The moving contact shall be made of electrolytic high conductivity copper of

adequate strength to withstand all thermal and bending stresses at the time of short circuits.

3. The fixed contacts shall be identical to the main isolator fixed contacts except

for silver plating.

4. The earthing of the moving contact shall be affected by flexible copper braids of adequate cross section to safely carry the short circuit current specified in clause 4.1 above.

5. The earthing switch of all poles of the isolator shall be mounted on the same

shaft and operated by a single and common operating handle, which shall be distinct and separate from that used for operating the isolator.

6. The moving contacts of the earthing switch shall close home simultaneously

in the fixed contacts.

7. Suitable counterweights shall be provided in the operating mechanism of the earthing switch, so that while opening the moving contact it does not come to rest with a jerk.

5.1.7 Terminal pad and terminal connectors.

1. The isolator shall be provided with hard drawn, extruded or rolled electrolytic copper terminal pad on either end and to be connected to the terminal connectors.

2. The terminal connectors shall be of bimetallic type to prevent electrolytic

corrosion and shall conform to RDSO’s standard drawings, which are enclosed with this specification. These shall be procured from RDSO’s approved manufacturers.

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5.1.8 Base channels

The isolator shall be complete with its steel mounting frame fabricated out of channels. The frame work shall be designed for a wind pressure of 150 kg/ sqm. acting on the whole of the projected area in addition to the other loads.

5.1.9 Material for various components

1. The blades of the isolator shall be of electrolytic high conductivity copper with the ends silver plated (minimum thickness 10 microns) and of adequate strength to withstand all thermal and bending stresses, particularly, at the time of passage of short circuit currents.

2. The fixed contacts of the isolator shall be made out of copper, either extruded,

rolled or drawn. They shall be silver plated (minimum thickness 10 microns).

3. Bolts, nuts and other fasteners of 12 mm dia or less shall be of stainless steel. Higher sizes of fasteners may be of hot-dip galvanized steel to RDSO’s specification no. ETI/OHE/13 (4/84). Spring washers wherever used shall be of phosphor bronze. The fasteners shall be procured from RDSO’s approved manufacturers.

4. All ferrous parts used in the manufacture of the isolator shall be hot-dip

galvanized to RDSO’s specification no. ETI/OHE/13 (4/84). 5.1.10 Earthing

1. The frame of the isolator shall be provided with two earthing studs of size M 16, complete with flat washer, nut and locknut, for connection to the earth mat with the help of MS flat. The earthing stud shall be marked with “Earth” symbol.

2. Two numbers each of earthing terminals shall be provided for earthing the

operating mechanism boxes of the isolator and the earthing switch.

5.1.11 Operating Mechanism. 5.1.12 Isolator

1. The isolator shall be suitable for being conveniently operated manually from the ground level without any strain. The design shall permit the length of operating rod to be so adjusted that, with the isolator mounted in working position, the rotating shaft of the operating mechanism on which the operating handle would be connected is at a height of 1.1 m from the ground level.

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2. Operating mechanism shall be provided with a sealed type reduction gear unit so as to facilitate easy operation of the isolator. Means for greasing the gear assembly shall be available for periodical maintenance of the unit.

3. Suitable arrangement shall be made on the inner side of the operating

mechanism door for keeping the operating handle when not in use.

4. A mechanical ON / OFF indicator shall be provided on the operating mechanism box for indicating the isolator position. This indicator should be visible from a distance.

5. The operating mechanism shall be designed in such a way so that, with

minimum modifications, the isolator can be converted from manual to motor operated.

6. The operating mechanism and accessories shall be enclosed in a weather, dust

and vermin proof cabinet of sheet steel construction having a minimum thickness of 2 mm. The operating mechanism box shall be hot-dip galvanized to RDSO’s specification no. ETI/OHE/13 (4/84).

5.1.13 Earthing Switch

1. Earthing switch shall be suitable for being conveniently operated manually from ground level without any strain. The design shall permit the length of operating rod to be so adjusted that, with the earthing switch mounted in working condition, the hinge pin of the operating handle is at a height of 1.1 m from the ground level.

2. The operating handle shall rest in the vertical position, both when the earthing

switch is in Open / Close position.

3. A mechanical ON / OFF indicator for earthing switch position, when the operation of the earthing switch is complete, shall be provided on the earthing switch assembly. This indicator should be visible from a distance

4. A weather, dust and vermin proof cabinet of sheet steel construction having a

minimum thickness of 2 mm shall be provided for housing the interlock and integral lock. The cabinet shall be hot-dip galvanized to RDSO’s specification no. ETI/OHE/13 (4/84).

5.1.14 Cylindrical post insulators (Support insulators).

1. The cylindrical post insulators shall conform entirely to RDSO’s specification no. ETI/OHE/64 (10/88) including the latest amendment. However, the salient characteristics of the insulators are given below for ready reference.

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--------------------------------------------------------------------------------------------------- S. No. Particulars Rated System voltages --------------------------------------------------------------- 72.5 kV 123 kV 145 kV 245 kV (1) (2) (3) (4) (5) (6) --------------------------------------------------------------------------------------------------- (i) Nominal system 66 kV 110 kV 132 kV 220 kV

voltage (ii) Overall height 770 1200 1500 2300

± 1 % ± 1 % ± 2.5 % ± 2.5 % (iii) Maximum diameter 195 mm 210 mm 270 mm 300 mm

of insulating part (iv) Top metal fitting 127 mm 127 mm 127 mm 127 mm

pitch circle diameter (v) Bottom metal fitting 127 mm 127 mm 127 mm 200 mm

pitch circle diameter

(vi) Minimum creepage 1810 3075 3625 6125 distance mm mm mm mm

(vii) Visible discharge 53 kV 88 kV 106 kV 176 kV test voltage

(viii) Wet 1 minute 160 kV 230 kV 275 kV 460 kV

power frequency (rms) (rms) (rms) (rms) withstand voltage

(ix) Impulse voltage 350 kVp 550 kVp 650 kVp 1050 kVp withstand value

(x) Minimum failing 4 kN 4 kN 4 kN 4 kN

load in bending

(xi) Minimum failing 35 kN 50 kN 60 kN 80 kN load in tension

(xii) Minimum failing 2 kNm 3 kNm 3 kNm 3 kNm

load in torsion

(xiii) Minimum failing 70 kN 100 kN 120 kN 160 kN load in compression.

---------------------------------------------------------------------------------------------------

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2. The insulator shall be procured only from RDSO approved manufacturers. 5.2 Locking and interlocking. 5.2.1 Isolator

1. The operating mechanism box shall have provision for a padlock for locking its door.

2. The isolator shall have provision for locking its main rotating shaft with the

help of padlock, both in ‘Open’ as well as in ‘Closed’ positions. The pad locking in any intermediate position shall not be possible.

3. Besides the above, the isolators shall have two locking mechanisms, for the

purpose of interlocking with the associated circuit breaker(s). The interlocking shall be as per Scheme – I and II detailed in Drg. No. ETI/PSI/5212 attached with this specification. The locks for this purpose shall not be in the scope of supply by the successful tenderer. However, mounting arrangement for these locks shall be provided by the manufacturer in such a way that it is possible to insert the key(s) from outside for operation of lock(s). The successful tenderer shall coordinate with manufacturer of circuit breaker and the Purchaser for this purpose.

5.2.2 Earthing switch

1. The operating mechanism box shall have provision for a padlock for locking its lid.

2. A mechanical interlock shall be provided in the operating mechanism of

isolator and earthing switch, so that operation of earthing switch is possible only when the isolator is locked in open position. This interlock shall also prevent closing of isolator unless earthing switch is locked in open position.

3. An integral lock shall be fitted in the operating mechanism box of the earthing

switch for locking the operating mechanism both in ‘Open’ as well as ‘Closed’ positions.

4. The design of the earthing switch shall be such as to permit use of a padlock

for locking the operating handle of the earthing switch both in ‘Open as well as ‘Closed’ positions.

5.2.3 The locking mechanism mentioned in clause 5.4.2 (3.) shall be housed within the

operating mechanism box. It shall however, be possible to insert the key from outside for operation of lock.

5.2.4 The integral lock as mentioned in 5.4.2 (3) shall be procured from RDSO’s approved suppliers.

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5.2.5 Bearings. 5.2.6 The design and construction of various bearings shall embody all the features

required to withstand the climatic conditions specified to ensure reliable operation even after long periods of inaction. The bearings used shall be of maintenance free construction for entire life of the isolator.

5.2.7 Support structure.

1. The support structure shall not form part of the tender and shall be arranged by the Purchaser. Details if the drilling schedule of the holes for the purpose of mounting the isolators on the support structure shall be ascertained by the successful tenderer from the purchaser before manufacturing the prototype unit.

2. The isolator and the earthing switch (wherever provided) shall be mounted

rigidly in upright position on the support structure. The height of the support structure from the ground level, for all types of isolators shall be 3000 mm.

5.2.8 Tandem pipes. 5.2.9 For smooth operation of the isolator, and to avoid bucking and bending of the tandem

pipes of the isolators, while opening or closing, an arrangement as indicated in Sketch No. ETI/PSI/SK/322 enclosed with the specification, shall be provided. An adjustable turn buckle / nut shall be provided (as shown in the sketch), for adjusting the length of the tandem pipe(s) at site.

5.2.10 Name Plate. 5.2.11 The isolator and the earthing switch shall be provided with a separate nameplate each,

which shall be water proof and corrosion proof, and mounted such that it is clearly visible by a person standing on the ground. Following information shall be indicated indelibly on these nameplates:

Isolator

- Name of Manufacturer

- Type designation

- Serial Number

- Rated voltage

- Rated current

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- Basic Insulation level

- Rated short time withstand current for one second

- Weight

Earthing Switch

- Name of Manufacturer

- Type designation

- Serial Number

- Rated voltage

- Rated short time withstand current for one second 6. TESTING 6.1 Type tests.

Only after all the designs and drawings have been approved and clearance given by RDSO to this effect, the manufacturer shall take up the manufacture of the prototype for RDSO inspection. It is to be clearly understood that any changes required to be done in the prototype as required by RDSO shall be done expeditiously.

Following tests shall be carried out on the prototype unit of the isolator and earthing switch at the works of the manufacturer / sub-contractor or at a reputed testing lab., in the presence of Indian Railways representative(s) in accordance with the relevant governing specification (and as modified or amplified hereunder against each test).

Isolator

a) General visual inspection and dimensional verification to check its conformity

with the approved drawings.

b) Dielectric tests - One minute power frequency voltage wet withstand test :

This test shall be carried out in accordance with clause 3.1 of IS 9921

(Pt.4) – 1985. The values of the test voltages shall be as specified in item (vi. (a)) of clause 4.1 hereof.

- Standard lightning impulse voltage withstand test :

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This test shall be carried out as per clause 3.1 of IS 9921 (Pt. 4) – 1985. The values of the test voltages shall be as specified in item (vi. (b)) of clause 4.1 hereof.

c) Temperature rise test

This test shall be carried out in accordance with clause 3.2 of IS 9921 (Pt.

4) – 1985. The temperature rise shall not exceed the values specified in Clause 4.1, item (xi.) hereof.

d) Measurement of contact resistance on each pole of the isolator

i) This test shall be conducted before carrying out temperature

rise test and shall be repeated after carrying out mechanical endurance test. The measured resistance after carrying out mechanical endurance test shall not vary by more than 20 % of the resistance measured before carrying out temperature rise test.

ii) The measurement of contact resistance shall be carried out as

per clause 3.2.5 of IS 9921 (Pt. 4) – 1985.

e) Short time withstand current test

This test shall be conducted in accordance with clause 3.3 of IS 9921 (Pt. 4) – 1985. The rated value of short time withstand current and dynamic peak withstand current shall be as specified in item (ix) and item (x) of Clause 4.1, hereof.

f) Mechanical endurance test

This test shall be conducted in accordance with clause 3.5.3 of IS 9921 (Pt. 4) – 1985.

Earthing switch (wherever provided) a) Short time withstand current

This test shall be conducted in accordance with clause 3.3 of IS 9921

(Pt. 4) – 1985.

b) Measurement of contact resistance of each earthing contact both before as well as after mechanical endurance test:

This test shall be conducted in accordance with clause 3.2.5 of IS 9921 (Pt. 4) – 1985. The measured resistance after carrying out mechanical endurance test shall not vary by more than 20 % of the resistance measured before carrying out mechanical endurance test.

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a) Mechanical endurance test This test shall be carried out in accordance with clause 3.5.3 of IS 9921 (Pt. 4) – 1985.

Galvanisation test

Two samples / cut pieces of each type of galvanized component shall be tested for conformity to RDSO Spec. No. ETI/OHE/13 (4/84). Chemical composition and physical tests on contact material, fasteners and springs.

The manufacturer shall submit test certificates to prove the conformity of the components as per following specifications :

i) Chemical composition of copper - IS : 191 - 1967

tube / strip

ii) Chemical composition of stainless - RDSO Spec. No. steel fasteners. ETI/OHE/18 (4/84).

iii) Physical tests on fasteners - - do –

iv) Physical tests on springs - IS : 7906 (Pt. 2) – 1985

v) Physical tests on copper - IS : 1897 – 1983.

strips / tubes. 6.2 Routine tests.

The isolator and the earthing switch (wherever provided) shall be subjected to the following routine tests at the manufacturer’s works:

a) General visual inspection and dimensional verification to check its

conformity with the approved drawings.

b) Power frequency voltage dry withstand tests (on the isolator only) This test shall be carried out in accordance with clause 4.1 of IS 9921 (Pt. 4) – 1985. c) Measurement of contact resistance

This test shall be carried out in accordance with clause 4.3 of IS 9921 (Pt. 4) – 1985.

d) Mechanical operating test

This test shall be carried out in accordance with clause 4.4 of IS 9921 (Pt. 4) – 1985.

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e) Assembly and interchangeability test The isolator and earthing switch (wherever provided) shall be assembled using components picked up at random from different lots. No adjustment shall be permitted in any component while assembling the isolator and earthing switch. The isolator shall function smoothly after assembly.

7. The manufacturer shall maintain complete record of the quality assurance test carried

out by him to ensure quality of raw materials and show them to the Inspector of the Purchaser as demanded.

8. BULK MANUFACTURE: 8.1 Only after clear written approval of the results of the tests on the prototype is

communicated by RDSO / Purchaser to the manufacturer, shall he take up bulk manufacture of the equipment which shall be strictly with the same material and process as adopted for the prototype. In no circumstances shall material other than those approved in the designs / drawings and / or the prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

8.2 If the prototype of an isolator or earthing switch conforming to this specification has

been approved for earlier supplies to Indian Railways, testing of prototype again may be waived provided that no changes in the design or material(s) used have been made.

8.3 Technical Data and Drawings : 8.3.1 The tenderer shall furnish along with his offer the guaranteed performance data and

other technical particulars of the equipment in the proforma attached at Annexure ‘A’ hereof. All the ratings guaranteed shall have to be proved by tests / test reports.

8.3.2 The information furnished in the schedule of guaranteed technical performance data

and other particulars shall be complete in all respects. If there is any entry like “shall be furnished later” or blanks are left against any items of Schedule of guaranteed particulars, the tender is not likely to be considered as such omissions causes delays in finalizing the tender.

8.3.3 Reports of type tests, if conducted on the similar equipment shall also be furnished. 8.3.4 The tenderer shall specifically indicate in a statement attached in his offer, his

compliance with each clause and sub-clause of the Specification. If any vague remark on any clause or sub-clause of this specification is given by the tenderer, then the tender submitted by him is not likely to be considered. A separate deviation statement shall be furnished with the offer drawing attention to the clause(s) where the tenderer seeks deviation giving detailed remarks / justification thereof. If there are no deviations, a ‘NIL’ statement shall be furnished.

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8.4 The tenderers shall furnish along with tender the following drawings:

i) General arrangement drawings showing the outline dimensions of isolators and earthing switch (wherever provided). ii) Drawing for support insulators along with salient technical particulars. iii) Drawing for operating mechanism of main isolator. iv) Drawing for operating mechanism of earthing switch.

8.5 The successful tenderer shall be required to submit the following detailed

dimensioned drawings including drawings already mentioned in clause 8.5 above, as per Railways standards in size of 210 mm x 297 mm or in integral multiple thereof, for approval :

i) Drawing showing details of main contacts.

ii) Drawing showing details of earthing contacts.

iii) Drawing of interlocking arrangement.

iv) Drawing of Castell type integral lock.

v) Drawing showing the mounting details of isolator.

vi) Drawing of terminal connector.

vii) Drawing showing the loads exerted by the isolator & earthing switch

(wherever provided) for designing the mounting structure. This drawing should furnish complete information regarding loads and their point of application.

8.5.3 After approval, six copies of approved drawings along with two sets of reproducible

prints shall be supplied to each consignee. Two copies of along with one set of reproducible prints shall be supplied to the Director General (TI), Research, Designs and Standards Organisation, Manak Nagar, Lucknow-226 011.

9. INSTALLATION, OPERATION & MAINTENANCE:

Twenty sets of installation, operation and maintenance instructions shall be supplied to the Purchaser with every order. Two copies of these instructions shall be supplied to the Director General (TI), RDSO, Manak Nagar, Lucknow. The information shall necessarily include :-

i) Erection procedure and precautions to be taken while erecting the

equipment.

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ii) The maintenance procedure to be adopted under normal service conditions. It is desirable that the manufacturer should specify the number of operations (or the time) after which different parts of isolator or earthing switch are to be maintained.

iii) Information regarding complete overhauling of isolator and earthing

switch.

iv) Replacement instructions of parts which are subject to deterioration during service for instance, contacts.

v) List of spare parts required for 5 years maintenance.

vi) List of special tools required for maintenance / replacement.

vii) Lubrication instructions including type of lubricants and quantity to be

used. 10. PACKING AND DISPATCH: 10.1 Various components of each isolator shall be securely packed in wooden crates and

boxes. It shall be ensured that one crate / box does not contain components of more than one isolator. General packing list, together with weight and overall dimensions of packing cases shall be furnished for each isolator indicating the following: --------------------------------------------------------------------------------------------------- Crate / Description of item / Approx. gross Approximate Box No. components in the weight in kg. outside crate / box dimensions. ---------------------------------------------------------------------------------------------------

10.2 As far as possible, the gross weight of the crate / box shall be so kept that it should be

possible to do manual handling by two / three persons. 10.3 Necessary instructions for handling and storage shall also be furnished for use at the

receiving end.

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Annexure – A to Specification

No. ETI/PSI/122 (3/89)

SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND OTHER PARTICULARS ------------------------------------------------------------------------------------------------------------ S. No. Description Unit of

measurement ------------------------------------------------------------------------------------------------------------ 1. Name of the manufacturer 2. Country of origin 3. Standard specification on which

performance is based. 4. Manufacturer’s type designation. 5. Rated voltage kV 6. Voltage rating class kV

(highest system voltage) 7. Rated current

a) Isolator A b) Earthing switch A

8. Rated frequency Hz. 9. Rated insulation level

a) Rated one minute power frequency wet withstand voltage

(i) To earth and between poles kV (rms) (ii) Across isolating distance kV (rms)

b) Rated one minute power frequency dry withstand voltage

(i) To earth and between poles kV (rms) (ii) Across isolating distance kV (rms)

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c) Standard lightning impulse

(1.2 / 50 micro second) withstand voltage

(i) To earth and between poles kVp (ii) Across isolating distance kVp

10. Rated short time withstand current (for 1 second)

(i) Isolator kA (rms) (ii) Earthing Switch kA (rms)

11. Dynamic peak withstand current : (i) Isolator kAp (ii) Earthing Switch kAp 12. Maximum temperature rise over an

ambient temperature of 40 deg. C when carrying its rated current. Deg. C (i) Copper contacts. (ii) Terminal pad of the isolator

to be connected to terminal connectors by both.

(iii) Metal parts acting as spring.

13. Breaking capacity of capacitive current at rated voltage. A

14. Number of poles Number 15. Number of breaks per pole Number

16. Total length of break per pole mm

17. Centre distance between poles mm

18. Minimum clearance in air

(a) Between poles mm

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(b) Between the live part and earth mm (c) Between open contacts of the

same pole mm (d) Isolating distance mm 19. Contact

a) Material of the moving contact

b) Material of the fixed contact

c) Thickness of silver coating Micron

d) Contact pressure kg.

20. Operating mechanism

a) Type

b) Height of the rotating shaft on which operating handle shall be connected m

c) Thickness of the steel metal for

operating mechanism box m

d) Gear ratio

e) Number of turns the handle is to be rotated to fully close the isolator from its fully open position Number

f) Weight of the operating mechanism kg. 21. Insulator

(a) Name of manufacturer (b) Type designation

(c) Standard specification on which

performance is based. IS

(d) Number of stack

87

(e) Weight of one insulator. kg.

(f) Number of insulators used

(i) Support (ii) Rotating / operating

(g) Wet power frequency withstand

voltage (1 minute) kV (rms) (h) Dry power frequency withstand

voltage (1 minute) kV (rms) (i) Visible discharge test voltage kV (j) Impulse withstand voltage kVp

(k) Wet power frequency flashover

voltage kV (rms)

(l) Dry power frequency flashover voltage kV (rms)

(m) Puncture voltage kV (rms) (n) Minimum failing load in bending kN

(o) Minimum failing load in tension kN

(p) Minimum failing load in torsion kN

(q) Minimum failing load in compression kN

(r) Creepage distance in air mm

(s) Shed profile

22. Type of bearings used in the isolator 23. type of material and terminals. 24. Total weight

(i) Isolator kg (ii) Earthing Switch kg

25. number of closing and opening

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operations, the isolator can perform without deterioration of its contacts. Additional information

26. Is the contact silver plated? Yes / No 27. Is the pad locking arrangement for

operating mechanism box provided? Yes / No 28. Is the mounting arrangement for

interlock(s) on isolator operating mechanism provided? Yes / No

29. Is integral lock on earth mechanism

provided? Yes / No 30. Is the mounting arrangement for

interlock with associated isolator provided? Yes / No

31. Is the mechanical mounting arrangement

between earthing switch and the isolator provided? Yes / No

32. Is material of fasteners of 12 mm dia

and below stainless steel? Yes / No 33. Is material of fasteners of above 12 mm

dia galvanized iron? Yes / No

34. Is frame work of the isolator made out of steel galvanized? Yes / No

35. Two number each of earthing studs

provided for: (a) Isolator frame Yes / No (b) Earthing switch frame Yes / No (c) Operating mechanism box Yes / No (d) Earthing symbol provided Yes / No

36. Is the height of operating handle hinge pin in earthing switch from ground level 1.1 m. Yes / No

89

37. Is arrangement for keeping the

operating handle for isolator in the operating mechanism box provided? Yes / No

38. Can the isolator be converted to

motor operated one with minor modification (if yes, sketch to be shown for modification required)? Yes / No

39. Is the operating mechanism box for

the isolator is weather, dust and vermin proof? Yes / No

40. Is ON / OFF indicator provided for

(i) Isolator Yes / No (ii) Earthing Switch Yes / No

41. Is padlocking provided for

(a) Main rotating shaft of isolator Yes / No (b) Operating handle for earthing switch Yes / No

(c) Cover for operating mechanism box Yes / No 42. Are the bearings used for maintenance

free design? Yes / No

43. Are the drawings as per clause 8.5 submitted along with the tender? Yes / No

90

APRIL – 1990 Addendum / Corrigendum Slip No.1 to Specification No.ETI / PSI /122 (3/89) for 245 kV, 145 kV, 123 kV, 72.5 kV, Double Pole and Triple Pole Isloator for Railway Traction Substations. ******** Page 4, Clause 4.1 - Read the existing value of 25 KA (rms) under Sl.No.(ix) Column 5 as 31.5 kA (rms) & Page 6, Clause 4.3.1 Sl.No.(v)

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RDSO Specification No. ETI / PSI / 122 / (3/89) for Double Pole & Triple Pole Isloator 110 kV. The following amendments are made in addition to the addendum and corrigendum slips issued to the specification. Sl.No. Para No. Amendment 1. Para 3.1(ii) Substitute 0ºC with 5ºC 3.1 (vii) Substitute 200 kg / sq.m with 112.5 kg / sq.m

2. 5.1.7.2 In line 3, add the word “preferably” after the word “procured” 3 5.1.9.3 In line 4, add the word “preferably” after the word “procured” 4. 5.4.4 In line 2, add the word “preferably” after the word “procured” 5. 5.6.1 In line 1 & 2, delete the words “and shall be arranged by the purchaser” 6. 6.1 In line 2, 3 & 4 add the word “purchaser /” “before the word “RDSO”

7. 9 In line 1, substitute “twenty” with “three”

92


SPECIFICATION

FOR

SOLID CORE PORCELAIN INSULATORS

FOR 25kV A.C. 50 Hz SINGLE PHASE OVERHEAD

TRACTION LINES

NO.ETI/OHE/15 (9/91)

93

SPECIFICATION NO. ETI / OHE / 15 (9/91)


RESEARCH DESIGN AND STANDARDS ORGANISATION MANAK NAGARLUCKNOW – 226 011

SPECIFICATION

FOR

SOLID CORE PORCELAIN INSULATORS

FOR

25 kV AC, 50 Hz, SINGLE PHASE OVERHEAD

TRACTION LINES

ISSUED BY

TRACTION INSTALLATION DIRECTORATE RESEARCH DESIGN AND STANDARDS ORGANISATION

MANAK NAGARLUCKNOW – 226 011

94

ETI/OHE/15 (9/91)

SPECIFICATION FOR SOLID CORE PORCELAIN INSULATORS F OR 25 kV AC, 50 Hz, SINGLE PHASE OVERHEAD TRACTION LINES.

1. SCOPE : 1.1 This specification covers the requirements and method of test for solid core porcelain

insulators, both for normal and polluted zones, used on single phase overhead electric traction lines having a nominal voltage of 25 kV, (line-earth) AC at 50 Hz. The system voltage may, however, go up to 27.5 kV.

1.2 This specification supersedes the one issued in November 1988. 1.3 Reference has been made in this specification to the latest edition of the following

Indian and other standard specifications: (i) IEC Publication 383 - Tests on insulator on ceramic material or glass

for overhead lines with a nominal voltages greater than 1000 V.

(ii) IEC Publication 507 - Artificial pollution tests on high voltage

Insulators to be used on a.c. systems.

(iii) IEC Publication 575 - Thermal mechanical performance tests and

mechanical performance test on string insulator units.

(iv) IEC Publication 591 - Sampling rules and acceptance criteria when

applying statistical control methods for mechanical and electromechanical tests on insulators of ceramic material or glass for overhead lines with a nominal voltage greater than 1000 V.

(v) IEC Publication 672-2 - Specification for ceramic and glass Insulating materials.

Part 2: Methods of test. (vi) IEC Publication 815 - Guide for the selection of insulators in respect of polluted conditions.

95

(vii) IEC Publication 36 B - Insulators for overhead lines – AC power arc tests (Secretariat) 102 on insulator sets for overhead lines with a

nominal voltage greater than 1000 volts (draft). (viii) IS:2071 (Part I to III) - Methods of high voltage testing. (ix) IS:2108 - Specification for black heart malleable iron

castings. (x) IS:4218 - ISO metric screw threads. (Part I to VI) (xi) IS:8704 - Methods for artificial pollution tests on high

voltage Insulators for use on a.c. systems.

(xii) JIS-C-3802 - Permissible limits of visual defects for

insulating porcelains.

(xiii) ETI/OHE/13 (4/84) - Specification for hot dip zinc galvanisation of

issued by Research of steel masts (rolled and fabricated), tubes and Designs and Standards fittings used on 25 kV AC OHE. Organization (RDSO)

1.4 In case of any conflicts between the contents of the above IEC, BIS, JIS

specifications and this specification, the latter shall prevail. 1.5 Any deviations from this specification, calculated to improve the performance, utility

and efficiency of the insulator proposed by the Tenderer, will be given due consideration, provided that full particulars with justification therefore are furnished. In such a case the tenderer shall quote according to this specification and indicate the deviation(s) separately in a “Statement of Deviations”, with the prices, if any, for such deviations.

2. TERMINOLOGY : 2.0 For the purpose of this specification, the following definitions shall apply. 2.1 Solid core Porcelain Insulator : An insulator consisting of a porcelain element of solid

core construction and associated metal fittings intended to give support to a live part which is to be insulated from earth or from another live part.

2.1.1 Stay Arm Insulator : The insulator which forms part of the horizontal member, known

as the stay arm of the cantilever assembly from which the traction conductors are

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suspended, and which insulates that member from the mast or structure to which the cantilever is attached.

2.1.2 Bracket Tube Insulator : The insulator which forms part of the inclined member,

known as the bracket tube, of the cantilever assembly from which the traction conductors are suspended, and which insulates that member from the mast or structure to which the cantilever is attached.

2.1.3 9-Tonne Insulator : The insulator is normally, though not exclusively, used as a strain

insulator for anchoring of conductors. It is also used in a vertical position to support 25 kV feeder wire.

2.1.4 Operating Rod Insulator : The insulator used in the operating rod of a 25 kV isolator

for opening and closing of the isolators. 2.1.5 Post Insulator : A post insulator is used for supporting rigidly the live contacts of 25

kV isolator switches, the 25 kV bus bars at sub-stations / switching stations, the 25 kV bus bars over portals and at such other locations.

2.1.6 Sectioning Insulator : The insulating element of a piece of equipment (called section

insulator assembly) which is used for separating adjacent sections of the overhead traction line belonging to different elementary electrical sections in the normal condition and which provides a continuous mechanical and electrical path for passage of the pantograph of electric rolling stock.

2.2 Standard Insulator : This insulators is used in zones in which pollution level is either

light or there is no pollution. Such an insulator has a creepage distance of 850 mm and is termed as “Standard Insulator”.

2.3 Polluted Zone Insulator : This insulator is used in medium and heavily polluted zones.

Such an insulator has a creepage distance of 1050 mm and is termed as “Polluted Zone Insulator”.

Note :- IEC Publication 815 prescribes from the point of view of pollution level, four

levels of pollution from light pollution to very heavy pollution, for the purpose of standardization. In order avoid a multiplicity of types of insulators to suit each pollution level it is considered advantageous to standardize two types of insulators, one for light pollution or where there is no pollution and the other for medium or heavy pollution as indicated in clause 2.2 and 2.3 respectively. At present only stay arm, bracket tube and 9-tonne insulators are being developed for use in zones where the pollution level is medium and / or heavy.

2.4 Dry Lightning Impulse Withstand Voltage : The lightning impulse voltage which the

insulator withstands dry, under the test conditions prescribed in clause 6.1.5.4.

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2.5 Wet Power Frequency Withstand Voltage : The power frequency voltage which the insulator withstands wet, under the test conditions prescribed in clause 6.1.5.5.

2.6 Mechanical Failing Load : The greatest mechanical load which under the prescribed

conditions, causes separation or breakage of metal fittings or total breakage of the insulator.

2.7 Creepage Distance : The shortest distance along the contours of the external surfaces of

the ceramic insulating part of the insulator between those parts which normally have the operating voltage between them. The distance measured over the surface of the cement used as jointing material shall not be considered as forming part of the creepage distance.

2.7.1 If high resistance coatings are applied to the parts of the insulator, such coatings shall

be considered as effective insulating surfaces and distances over them shall be included in the creepage distance. The surface resistivity of such high resistance coatings is usually about 106 ohm, but may be as low as 104 ohm.

2.8 Bulk Density : The quotient obtained by dividing the mass of the test specimen by the apparent volume (including open and closed pores).

2.9 Lot of Insulators : All the insulators of the same type and design manufactured under

identical conditions of production, offered for acceptance. A lot may consist of the whole or part of the quantity ordered.

2.10 Batch of Insulators : A batch of insulator shall be the complete number of insulators

manufactured at one time for the purpose of conducting prescribed type tests during the process of inspection and testing of prototype. Along with this batch of insulators, shall also be manufactured the required number of test specimens for the same purpose. A special marking shall be given to identify the batch of insulators and test specimens manufactured together.

2.11 Type Tests : Tests carried out to prove conformity with the requirement of the

specification. These tests are intended to prove the general quality and design of a given type of insulator. They shall be repeated when the design or the material of the insulator is changed.

2.12 Acceptance Tests : These tests are for the purpose of verifying the mechanical

characteristics as well as the required properties of the ceramic portion of insulator and other characteristics as considered necessary. They are made on insulators picked up at random from lots happened for acceptance.

2.13 Routine Tests : These tests are for the purpose of eliminating insulators with

manufacturing defects. They are made on every insulator offered for acceptance.

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3. STANDARD ATMOSPHERIC CONDITIONS 3.1 Standard atmospheric conditions for tests on insulators shall be as given below:

Temperature t 20 °C. Barometric pressure b 1013 mbar. Absolute humidity h 11 g of water per m3 corresponding to 63% relative

humidity at 20 °C. Note: A pressure of 1013 mbar corresponds to a pressure of 760 mm of mercury at 0

°C. If the height of the barometer is h mm of mercury and the temperature of the mercury is t °C, the atmospheric pressure in mbar is: 1013 h

P = ----------- (1 – 1.80 x 10-4 x t) 760

3.2 Electrical test shall, however, be carried out under conditions obtaining at the time of the tests. The barometric pressure, air temperature and humidity at the time of tests shall be recorded for the purpose of calculating the corrections to test voltages in accordance with Appendix “A”.

4. REQUIREMENTS 4.3 General. 4.3.1 The insulators covered by this specification are shown in Fig. 1 to 9 attached and are

for the general guidance of the manufacturers. The dimensions indicated in these Figures are essentially to be followed to ensure interchangeability.

4.3.2 The porcelain shall be sound, free from defects, thoroughly vitrified and fully glazed.

All the six types of insulators for normal zone and the three types of insulators for polluted zone shall be manufactured with aluminous porcelain only. The quality of the porcelain as well as the process by which the insulator is manufactured shall be such that when the insulator is subjected to flashover at the minimum arc current of 6 kA for 0.2 s followed by 2 kA for 0.2 s followed after a pause of 60 s by a further 6 kA for 0.2 s, it shall not part.

4.3.3 Since the insulator is of aluminous porcelain, its dimensions both of core and shed

shall be such that its weight shall be a minimum for the creepage distance specified and the mechanical and electrical characteristics it is required to meet.

4.3.4 The values of essential ceramic properties of the insulator are indicated in the Table – 1.

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TABLE –1 CERAMIC PROPERTIES

Property Value

i)

Bulk density 2.50 g/cm3 (minimum) on test specimen. 2.45 g/cm3 (minimum) on fired porcelain.

ii)

Modulus of elasticity 100 GPa (minimum)

iii) Flexural strength Unglazed Glazed

140 MPa (minimum) 160 MPa (minimum)

4.3.5 The sheds of an insulator shall be of equal diameter and with lips at the extremities

for all type of insulators, except for the sectioning insulator which has a symmetric shed profile. The shed profile shall be free from ribs on the underside so as to avoid accumulation of dust and pollutants.

4.3.6 The glaze shall be brown in colour, unless otherwise specified. It shall cover the

entire porcelain of the insulator. 4.3.7 The dimensional parameters characterizing the insulator profile shall generally

conform to IEC Publication 815. 4.3.8 The ends of the porcelain shell shall be either straight and sanded or conical and

glazed. If the ends are conical, the angle shall be 4° to 12°. Similarly, the internal angle of the metal fittings shall be 4° to 12°.

4.3.9 The metal fitting shall be made of black heart malleable cast iron conforming to

Grade BM: 340 of IS: 2108 or of spheroidal graphite cast iron to Grade: 400/12 of IS: 1865 with the prior approval of RDSO.

4.3.10 All metal fittings shall be hot-dip galvanized in accordance with specification no.

ETI/OHE/13 (4/84). The minimum weight of zinc coating shall be as follows:

Standard insulators : 160 g/m2 for all types of metal fittings including stay arm

insulator hook. Polluted zone insulators: (i) 1000 g/m2 for all types of metal fittings. (ii) 750 g/m2 for stay arm insulator hook. The metal fittings shall be galvanized after machining. The galvanized surface shall be smooth. The mass of zinc coating on stay arm insulator hook shall not be applicable to the threaded portion of the hook.

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Note : The threads of the tapped holes in the metal fittings of stay arm, operating rod and post insulators shall be cut after galvanization and protected against corrosion by application of suitable grease. The threads of all other metal fittings shall be cut before galvanization. All the tapped holes shall be suitable for galvanized bolts and shall conform to IS: 4218 (Part I to VI).

4.3.11 The jointing of the metal fittings with the porcelain shell shall be with Portland cement which shall neither react chemically with the metal fittings nor cause their fracture on account of expansion or contraction causing loosening of the metal fittings. During the jointing process care shall be taken to ensure that the porcelain shall and the metal fittings are properly aligned and that no part of the porcelain shall comes in direct contact with the metal fittings. It is permissible to use cork sheet or thick paper between the metal fitting and the porcelain shell to absorb any mechanical shocks.

4.4 Voltages for High Voltage tests. 4.4.1 The values of voltages at Standard Atmospheric Conditions for the various high

voltage tests on the insulators shall be as given in Table – 2. 4.4.2 One of the requirements of the insulator is to withstand artificial pollution test.

The insulator shall withstand 30 kV for 15 minutes at ESDDs of 0.05 mg/cm2 and 0.15 mg/cm2 for standard and polluted zone insulators respectively when tested in accordance with clause 6.1.5.6.

TABLE –2

VALUES OF VOLTAGES FOR HIGH VOLTAGE TESTS

Type of insulator

Visible discharg

e test

kV (rms)

Wet power frequency withstand voltage test

Dry lightning impulse withstand voltage test

Insulator vertical

kV (rms)

Insulator horizontal kV (rms)

Positive wave

kV (peak)

Negative wave

kV (peak) Stay arm 35 100 125 240 260 Bracket tube 35 100 125 240 260 9-tonne 35 100 125 240 260 Operating rod 35 100 125 240 260 Post 35 100 -- 240 260 Sectioning 35 -- 125 240 260

Note : These values apply to both standard and polluted zone insulators. 4.5 Minimum Mechanical Failing Loads and Bending and Torsional Moments. 4.5.1 The minimum mechanical failing loads and bending and torsional moments shall be

in accordance with Table – 3.

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TABLE –3

MINIMUM MECHANICAL FAILING LOADS AND BENDING AND TORSIONAL MOMENTS

Type of insulator Tension

(kgf) Tension with 80

mm eccentricity of load (kgf)

Bending moment (kgf.m)

Torsional moment (kgf.m)

Stay arm 5400 --- 100 --- Bracket tube 5400 --- 170 --- 9-tonne 9900 --- 210 --- Operating rod 2200 --- 70 --- Post 6000 --- 370 550 Sectioning --- 5000 --- ---

4.6 Marking. 4.6.1 The porcelain shell as well as the metal fittings of each insulator shall be legibly and

indelibly marked. The marking on the porcelain shell shall be with 10mm figures while that on metal fittings shall be with 6 mm relief figures to show the following: a) Name or trade mark of the manufacturer, b) Month (optional for the metal fittings) and year of manufacture,

c) Part number, and

d) Any other identification marks specified by the purchaser.

4.6.2 The marking on the porcelain shell shall be by printing and shall be applied before

firing. 5. DRAWINGS AND THEIR APPROVAL: 5.1 The successful tenderer shall submit three prints in each of the following drawings

showing all the details in scale 1 : 1, separately for each type of insulator (in the proforma for the drawing enclosed) as per Railway Standards in sizes of 210 mm x 297 mm or any integral multiple thereof for approval for the purpose of prototype test only.

i) Assembly drawing of the insulator. ii) Porcelain shell drawing. iii) Metal fittings drawings.

5.2 The drawing approved for the prototype tests only shall be modified, if need be, as a result of changes necessitated during testing or as desired by the purchaser. The

102

modification shall be first got approved by the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, Lucknow and then incorporated in the drawing and each such modification shall be got signed on the drawings by the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, Lucknow. If there are no modifications at all the drawings approved for prototype tests shall be treated as final.

5.3 After the insulator has passed all the type tests the successful tenderer shall submit the

original tracings of all the drawings which have been approved for prototype tests only along with two sets of reproducibles to Director General (Traction Installation) Research, Design and Standards Organization, Lucknow (India) and they will be signed by the authority concerned of the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, Lucknow in token of approval for bulk manufacture.

6. TESTS : 6.1 Type Tests 6.1.1 Once a purchase order is placed for supply of insulators the designs and drawings

shall be furnished to the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, Lucknow as the case may be within the period stipulated in the order. Only after the designs and drawings have been approved for prototype tests and a written advice given to that effect, shall the successful tenderer/manufacturer take up manufacture of the batch of the insulators and test specimens for prototype tests. It is to be clearly understood that any change or modification required by the above authorities to be done in the batch of insulators shall be done expeditiously, not withstanding approval having already been given for the designs and drawings. Such change or modification shall be incorporated in the drawing as indicated in Clause 5.2 above.

6.1.2 Prior to giving a call to the Purchaser / Director General (Traction Installation)

Research, Design and Standards Organization, Lucknow, for inspection and testing of the prototype, the successful tenderer/manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the tests and the number of days required to complete all the tests at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the purchaser reserves the right to conduct any additional test(s), besides those specified herein, on any insulator so as to test the insulator to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and representative of the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, during the process of testing as regards the procedure for type tests and/or the interpretation and acceptability of the results of type test, it shall be brought to the notice of the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, as the case may be, whose decision shall be final and binding. Only after the prototype is completed

103

and ready in each and every respect, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with at least 15 days notice for the purpose.

6.1.3 The batch of insulators and test specimens to be offered for type tests shall be not less

than the following:

Post insulator : 55 insulators and 9 test specimens * Sectioning insulator : 35 insulators and 9 test specimens * All other types of insulators : 45 insulators and 9 test specimens *

(* Out of the 9 specimens, 6 shall be glazed and 3 shall be unglazed)

6.1.3.1 The distribution of insulators for specific type tests shall be as follows:

Post Sectioning Others ------ ------------ --------

(a) Mechanical load test 30 10 20 (b) Mechanical performance test 10 10 10 (c) Thermal mechanical performance test 3 3 3 (d) High voltage electrical tests 3 3 3 (e) Power arc test 3 3 3 (f) Artificial pollution test 1 1 1 (g) Visual examination and verification (h) of dimensions 5 5 5

------- ---------- -------- Total 55 35 45

------- ---------- -------- 6.1.4 Sequence for conducting the prototype tests:

Out of the batch of insulators, indicated in clause 6.1.3.1 of this specification of mechanical load tests and mechanical performance test shall be picked up at random and subjected to temperature cycle test. Only after passing the temperature cycle test, shall the insulator be subjected to mechanical load and mechanical performance tests. Only if the insulators pass the mechanical load and mechanical performance tests, shall other tests be taken up. If they do not pass these tests, all the remaining insulators shall be destroyed in the presence of the Inspecting Official and the manufacturer shall offer a fresh batch of insulators of improved quality for type tests. After completion of mechanical load and mechanical performance tests, the thermal mechanical performance test, high voltage electrical tests, power arc test and artificial pollution test shall be taken up at the works of the manufacturer or at any reputed laboratory, as the case may be. In case any of the tests is to be conducted at any independent laboratory, the insulators required for that test shall be sealed by the Inspecting Official before he leaves the manufacturer’s works. It shall be

104

ensured that the identification marks given on the seal, porcelain shell and the metal fittings are indicated in the test report given by the independent laboratory.

6.1.5 The following type tests shall be carried out on the batch of the insulators at the works of

the successful tenderer / manufacturer or at reputed testing laboratory in the presence of representative of the Purchaser / Director General (Traction Installation) Research, Design and Standards Organization, Lucknow and in accordance with the relevant procedures laid down in this specification:

1. Visual examination. 2. Verification of dimensions. 3. Visible discharge test. 4. Dry lightning impulse withstand voltage test. 5. Wet power frequency withstand voltage test and wet power frequency

maximum withstand voltage test. 6. Artificial pollution test 7. Temperature cycle test. 8. Mechanical load test. 9. Mechanical performance test. 10. Thermal mechanical performance test. 11. Porosity test. 12. Galvanization test. 13. Verification of eccentricity. 14. Determination of Bulk density. 15. Test of Flexural Strength. 16. Test of modulus of elasticity. 17. Analysis of chemical composition. 18. Power arc test.

Note : i) Temperature cycle test shall be conducted on 20 insulators in case of sectioning insulator, on 40 insulators in the case of post insulator and on 30 insulators in the

case of all other types of insulators. Only after passing this test, shall the insulators be subjected to mechanical load and mechanical performance test.

ii) In the mechanical load test, 10 insulators each shall be tested for tensile, bending,

torsion and eccentric loading as applicable to the type of the insulator indicated in clause 6.1.3.1.

iii) The mechanical performance test shall be conducted on 10 insulators.

iv) The Artificial pollution test shall be conducted on one insulator.

v) The galvanization test shall be conducted on 3 samples of metal fitting of the insulators broken in the mechanical load test and mechanical performance test for each type of insulator. This test shall be conducted on 3 samples of the hook in case of stay arm insulator.

105

vi) Test for Flexural strength shall be conducted on 3 glazed and 3 unglazed test specimens separately.

vii) Test of Modulus of elasticity shall be conducted on 3 glazed test specimens.

viii) The porosity test shall be conducted on at least three fragments or pieces of

porcelain from the insulators broken in the mechanical load and mechanical performance tests.

ix) Analysis of chemical composition shall be done on one fragment of the

unglazed test specimen broken in the test for flexural strength and on one fragment of the insulator broken in the mechanical load and mechanical performance tests.

x) All other tests shall be conducted on three insulators or three broken insulators

or three fragments or pieces of porcelain from the insulators broken in the mechanical load and mechanical performance tests as applicable to the type of test.

6.1.5.1 Visual examination :

The insulator shall be visually examined to see that it is free from physical distortion of shape and that the vitrified glaze is hard and smooth and the surface is free from cracks and any other defect likely to be prejudicial to satisfactory performance in service. The visual defects shall not exceed the limits permissible for the appropriate class of insulator as specified in JIS: C 3802. The cement for jointing shall be finished flush with the edge of the metal fittings and in any case shall not project more than 2 mm above the edge. The exposed surface of the cement shall not show any sign of crack or blow hole. The metal fittings shall be smooth without any excrescence.

6.1.5.2 Verification of dimensions :

The dimensions of the insulator shall be verified to see that they are in accordance with the approved drawings. Unless otherwise specified, a tolerance of +/- (0.03 d + 0.3) mm shall be permissible on any dimension of the porcelain shell only, “d” being the dimension in mm.

6.1.5.3 Visible discharge test :

The room in which the test is to be done shall be darkened completely and a period of at least five minutes shall be allowed for the observer to become accustomed to the darkness. A power frequency voltage of the value specified in TABLE-2 shall be applied in accordance with the procedure laid down in Appendix “B” and maintained at that value for five minutes. During the period, there shall be no signs for visible corona. The voltage shall then be

106

raise gradually and the value at which corona first appears shall be recorded. The voltage shall then be reduced gradually, and the value at which the corona just disappears shall also be recorded.

6.1.5.4 Dry lightning impulse withstand voltage test : The insulator shall be tested dry under the conditions described in Appendix

“B”. The impulse generator shall be adjusted to apply a standard 1.2/50 wave at the specified impulse withstand voltage adjusted for the atmospheric conditions at the time of test. Fifteen such voltage waves shall be applied to the insulator. If there is no flashover or puncture, the insulator shall be deemed to have passed the test. However, two flashovers on the external insulation is permissible. The insulator shall pass the impulse withstand voltage test with voltages of both positive and negative polarity. The insulators shall not be damaged by these tests, but slight marks on the surface of the insulating parts or chipping of the cement used for jointing of metal fitting shall be permissible. The original oscillogram recorded during the test shall form part of the type test report.

6.1.5.5 Wet power frequency withstand voltage test and wet power frequency

maximum withstand voltage test :

The insulator shall be arranged as described in Appendix “B” and exposed for at least 1 minute before application of voltage and throughout the test to artificial rain produced in accordance with clause 3.3 of IS: 2071 (Part-I). The test voltage to be applied to the insulator shall be the specified wet power frequency withstand voltage adjusted for the atmospheric conditions at the time of test. A voltage of about 75 % of the test voltage so determined shall be applied and then increased gradually to reach the test voltage in a time of not less than 5 s. The test voltage shall be maintained at this value for 1 minute. The insulator shall not flashover or puncture while the test voltage is applied. The test shall then be repeated at successively higher voltage in step of 2.5 kV or 5 kV until the insulator is unable to withstand the applied voltage for a period of 1 minute. The voltage, corrected as described in Appendix “A”, of the test immediately preceding the last test shall be taken as the maximum wet power frequency withstand voltage.

6.1.5.6 Artificial pollution test :

The artificial pollution test shall be carried out at the declared maximum withstand Equivalent Salt Deposit Density (ESDD) at 30 kV in accordance with IS: 3704 or IEC Publication 507, using solid layer (Steam fog) method. The insulator shall be in the vertical position during the test. The sectioning

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insulator however shall be tested in the horizontal position. The leakage current shall be recorded. If the insulator does not pass the test at the specified value of ESDD, the test shall be repeated at lower values.

6.1.5.7 Temperature cycle test :

The insulators for this test shall be complete along with their metal fittings. They shall be completely immersed in a water bath maintained at a temperature of at least 70 °C above that of cold water and left submerged for a period of T minutes, the value of T being given by the formula T = 15 + 0.7 M, where M is the mass of one insulator in kg. The insulators shall then be withdrawn as quickly as possible and completely immersed, without being placed in an intermediate container, in a bath of cold water for the same period of T minutes. This process of heating and cooling cycle shall be performed five times in succession. The time taken to transfer all the insulators from one bath to the other should be as short as possible and shall not exceed 30 s. The quantity of water in the two baths shall be sufficient so as not to cause a temperature variation of more than 5 °C between the water in the two baths when the insulators are immersed. Each insulator shall then be examined with the naked eye to see that the porcelain shell has not cracked, the glaze is not damaged and the metal fittings are not loose. Each insulator shall then be struck lightly with a wooden mallet to verify that there is no crack or loosening of the metal fittings.

6.1.5.8 Mechanical failing load tests :

These tests shall comprise tensile, bending, eccentric loading and torsion tests. 6.1.5.8.1 Tensile Test : This test shall be done on all the insulators except the sectioning

insulator. The load shall be applied to the insulator in line with its axis. It shall be increased at a rate agreed to between the manufacturer and the purchaser to 60 % of the specified minimum tensile failing load. It shall be maintained at this value for one minute and then raised at the same rate until separation or breakage of metal fitting or total breakage of the insulator occurs. The separation or breakage of metal fitting or total breakage of the insulator or any permanent deformation in the insulator and its components shall not occur before the load reaches the minimum tensile failing load specified in TABLE-3.

6.1.5.8.2 Bending Tests : This test shall be done on all the insulators except the

sectioning insulator. One end of the insulator shall be rigidly fixed in a suitable fixture so as not to cause the failure of the metal fitting of this end during the test which is for the porcelain shell only. The load shall be applied

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to the other end of the insulator in line with the diameter and in a direction perpendicular to the axis of the insulator and shall be increased at a rate agreed to between the manufacturer and purchaser to 60 % of the specified minimum failing bending moment, taking into account the distance between the top of the fixture and the point at which the load is applied. It shall be maintained at this value for one minute and then raised at the same rate until the total breakage of the porcelain shell occurs. The failing bending moment shall be calculated by multiplying the value of the load in kgf. and the distance from the point of application of load to the point of breakage in m and this value shall not be less than the minimum bending moment specified in TABLE-3.

NOTE: (1)The choice of the end to be fixed rigidly shall be left to the manufacturer.

(2)The recommended rates of increase of load in the tensile and bending tests are:

Tensile test : 200 to 300 kgf / s Bending test : 15 to 30 kgf / s. 6.1.5.8.3 Eccentric loading test : This test shall be done only on the sectioning insulator.

The load shall be applied by means of suitable jigs such that the line of application of the load is 80 mm away from and parallel to the longitudinal axis of the insulator (See Fig. 10). Care shall be taken to ensure that during the test, the jigs do not move and the distance of the load from the center line of the insulator does not become less than 80 mm. The load shall be increased at a rate agreed to between the manufacturer and the purchaser to 60 % of the specified minimum eccentric tensile failing load. It shall be maintained at this value for one minute and then raised at the same rate until separation or breakage of metal fitting or total breakage of the insulator occurs. The separation or breakage of metal fitting or total breakage of the insulator or any permanent deformation in the insulator and its components shall not occur before the load reaches the minimum eccentric tensile failing load specified in TABLE-3

6.1.5.8.4 Torsion test : This test shall be done only on the post insulator. The insulator

shall be subjected to a torsional load without causing any bending whatsoever. Depending upon the length of the lever arm used for imparting the torsion, the load corresponding to the minimum torsional failing moment shall be calculated and 60 % of the value of load so calculated shall be gradually applied at the end of the lever arm and maintained at that value for one minute. The load shall then be raised at the same rate till breakage of the porcelain shell takes place. The torsional moment shall be calculated with the load at which the porcelain shell breaks by multiplying the load and the lever arm length and that breakage shall occur at a torsional moment not less than the minimum specified in TABLE-3.

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6.1.5.9 Mechanical performance test :

This test shall be done on all the insulators in accordance with clause 4 of IEC Publication 575. The insulators shall be subjected to a tensile load (eccentric tensile load in the case of sectioning insulator) equal to 60% of the specified minimum failing load and immediately removed. This shall be done 4 times in quick succession. Thereafter the insulator shall be subjected to the tensile test (eccentric tensile test in the case of sectioning insulator) in accordance with clause 6.1.5.8. The separation or breakage of the metal fittings or the total breakage of the insulator or any permanent deformation in the insulator and its components shall occur not below the specified minimum failing load specified in TABLE-3. In case of the sectioning insulator, the line of application of the load shall be 80 mm away from and parallel to the longitudinal axis of the insulator.

6.1.5.10 Thermal Mechanical Performance Test :

This test shall be done on all the insulators in accordance with clause 3 of IEC Publication 575. before starting the thermal cycle, the insulators shall be subjected at room temperature to 60% of the tensile load (eccentric tensile load in the case of sectioning insulator) specified in TABLE-3. It shall then be subjected to four 24-hour cycles of cooling and heating of 12 hours duration each while maintaining the load. Each 24 hours cycle shall comprise cooling to –30 +/-5 °C and then heating to +40 +/-5 °C, the temperature figures being of the surrounding air. The sequence shall be first cooling and then heating. The test equipment shall be such as to permit the minimum and maximum temperatures being maintained during at least four consecutive hours of the cycle. The tensile load shall be completely removed and re-applied towards the end of each heating period, the last one excepted. On completion of the fourth 24 hour cycle and cooling to room temperature, the tensile load shall be removed. On the same day, after removal of the load, the insulator shall be subjected individually to mechanical load test in accordance with clause 6.1.5.8. The separation or breakage of the metal fittings or the total breakage of the insulator or any permanent deformation in the insulator and its components shall occur not below the specified minimum failing load specified in TABLE-3. In the case of the sectioning insulator, the line of application of the load shall be 80 mm away from and parallel to the longitudinal axis of each insulator, both during the thermal cycles and during the mechanical load test.

6.1.5.11 Porosity Test :

Fragments or pieces of porcelain from the insulator broken during any of the above tests shall be taken for this test. The unglazed area of the fragments shall be at least 75% of the total surface while some of the fragments shall be

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taken from the central parts of the ends of the porcelain. They shall be immersed in 1% alcoholic solution of fuchsin (1g fuchsin in 100g of methylated spirit) under a pressure not less than 150 kg/cm2 for a period such that the product of the test duration in hours and the test pressure in kg/cm2 is not less than 1800. The fragments or pieces shall then be removed from the solution, washed, dried and broken. Examination of the freshly broken surfaces with the naked eye shall not reveal any dye penetration. Any dye penetration into small cracks formed during the initial breaking process shall be neglected.

6.1.5.12 Galvanization Test :

The uniformity, adherence and mass of zinc coating shall be tested in accordance with specification no. ETI/OHE 13 (4/84) and the results of the tests shall meet the requirements specified. The mass of zinc coating shall be as specified in clause 4.1.10 herein.

6.1.5.13 Verification of eccentricity :

Insulators which have undergone mechanical load test shall be examined to verify the eccentricity of the metal fittings with respect to the porcelain shell by breaking the porcelain shell as near to the edge of the metal fitting as is possible. The eccentricity shall be not more than 2 mm in any case.

6.1.5.14 Determination of Bulk Density :

This test shall be conducted in accordance with clause 4 – Method B of IEC Publication 672-2. The test specimen shall consist of at least three fragments of total mass between 50g and 80g. Chips liable to become detached during further handling shall be eliminated and any dust shall be carefully removed by brushing under a water jet. The mass (m1) in g of the dry test specimen shall be determined. It shall be placed in a vessel on a wide-mesh brass netting located 1 cm from the bottom and covered with distilled water. The distilled water shall then be heated upto the boiling point and maintained at that temperature for 30 minutes. It shall then be allowed to cool to ambient temperature. The test specimen shall be removed, wiped lightly with a damp cloth to remove water on the surface only and the mass (m2) in g of the specimen when suspended in distilled water at about 23 °C shall be determined. The mass (m3) in g in air of the soaked sample shall be determined. The bulk density shall be calculated as follows : m1 x pw Bulk density = --------------- where pw is the density in g/cm3 of water at the

m3 – m2 test temperature.

The test shall be made on at least three samples of unglazed test specimens broken in the test for flexural strength and on al least three samples of

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porcelain shell obtained from the insulators broken during the mechanical load tests. The results of the tests shall be not less than the value specified in TABLE-1 for each sample of test specimen and porcelain shell.

6.1.5.15 Test for Flexural Strength :

This test shall be conducted in accordance with clause 5 of IEC Publication 672-2. the method of test shall be Method A – Three point bend method. The choice of the shape of test specimens shall be left to the manufacturer. The test shall be conducted both for the unglazed as well as glazed test specimens and the value for flexural strength for each specimen shall be not less than the value specified in TABLE-1.

6.1.5.16 Test for Modulus of Elasticity :

This test shall be conducted in accordance with clause 6 of IEC Publication 672-2 or by dynamic method with ultrasonic resonance frequency measurement using elastosonic non-destructive testing equipment. The value of the Modulus of Elasticity for each specimen shall be not less than the value specified in TABLE-1

6.1.5.17 Analysis of chemical composition :

One fragment or piece from the core of the insulator broken during mechanical load tests and one fragment or piece of porcelain of the unglazed test specimen broken during the test for flexural strength shall be subjected to complete chemical analysis. The test report shall be submitted along with the type test and acceptance test reports.

6.1.5.18 Power arc test :

The power arc test comprises flashing over at the maximum arc current of 6 kA for 0.2 s followed by 2 kA for 0.2 s followed after a pause of 60 s by 6 kA for 0.2 s and the insulator shall not part. It is understood that facilities available at present in the country do not permit of the test being conducted in the sequence required and therefore, the power arc test shall be done at 6 kA for 0.2 s followed after a pause of 60 s by 2 kA for 0.2 s followed after a pause of 60 s by 6 kA for 0.2 s, till such time as this sequence is modified. The insulator shall not part at the end of the test. Chipping / breakage of sheds shall however, be permitted. After completion of the test the insulator shall be subjected to mechanical load test in accordance with clause 6.1.5.8 of this specification. The original oscillograms recorded during the test shall form part of the type test report.

6.1.6 ACCEPTANCE CRITERIA 6.1.6.1 A single batch of insulators and test specimens manufactured and offered for

type tests in accordance with clause 6.1.3 shall pass all the type tests stipulated in clause 6.1.5 hereof.

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6.1.6.2 Apart from passing all the type tests, the quality index calculated on the basis of the results of the mechanical load test and mechanical performance test shall be equal to or more than the Acceptance Constant given in IEC Publication 591.

6.1.7 Only after approval of the original tracings of drawings incorporating

changes, if any, necessitated during the type tests and clear written approval of the results of the tests on the prototype is communicated by the Purchaser / Director General (TI) Research, Design and Standards Organization, to the manufacturer, shall he take up bulk manufacture of the insulator – which shall be strictly with the same materials and process of manufacture as adopted for the prototype. In no circumstances shall materials other than those adopted in the design / drawings and/or during the manufacture of prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

6.1.8 If the prototype of an insulator conforming to this specification has already

been approved in connection with previous supplies to Indian Railways, fresh testing of prototype of the insulator may be waived at the discretion of the Purchaser, provided that no changes whatsoever in the design or materials or process of manufacture have been made. However, the Purchaser reserves the right to test any insulator if he deems it necessary to do so in the light of experience gained from previous supplies.

6.1.9 Notwithstanding approval having been accorded to manufacture the bulk of

the insulators on the basis of the results of the type tests, the Purchaser reserves the right to conduct any type and number of tests, including destructive tests at any time during the process of bulk manufacture – without prior advice to the manufacturer. All facilities shall be made available to the Purchaser to conduct such tests – without any charge.

6.2 Acceptance Tests 6.2.1 The following shall constitute the acceptance tests.

1. Visual examination 2. Verification of dimensions 3. Temperature cycle test 4. Mechanical load test 5. Mechanical performance test 6. Porosity test 7. Galvanization test 8. Verification of eccentricity 9. Determination of Bulk density 10. Analysis of Chemical composition.

6.2.1.1 The tests shall be conducted as laid down in the relevant clauses hereof.

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6.2.2 CUSTOMER HOLD POINT

The manufacturer shall within 30 days after the placement of a purchase order

furnish the Quality assurance plan to Director General (Traction Installation) Research, Design and Standards Organization, Lucknow, who shall indicate in the Quality Assurance Plan the CUSTOMER HOLD POINT / POINTS (CHP) beyond which the next step in the manufacturing process will not be taken up and shall advice the CHP to the Purchaser / Inspecting O fficial, as the case may be, as well as to the manufacturer. The lot size to be offered for the acceptance tests shall be decided by the manufacturer. The Inspecting Official shall pick up at random 5% of the lot offered and conduct the test prescribed immediately preceding the first CHP. If the sample passes the test, the Inspecting Official shall give written permission to the manufacturer to proceed with the next step in the manufacturing process. This written permission shall form part of the acceptance test report. This procedure shall be repeated for each CHP. If during the test immediately preceding a CHP the sample fails, the manufacturer shall be advised in writing by the Inspecting Official. The manufacturer shall rectify the defect and offer the insulators again for tests. This written advice will also form part of the acceptance test report. A distinct numbering shall be given to identify the manufacturing / firing schedule. The format on the report of CHP shall be supplied to the Inspecting Official by Director General (TI) Research, Design and Standards Organization, Lucknow

6.2.3 The number of insulators (sample size) to be picked up at random from the lot

offered for acceptance tests shall be in accordance with the TABLE-4. NOTE : If the order is for a small quantities, the sample size shall be 3% of the quantity

ordered subject to a minimum of 3 and a maximum of 15 insulators in case of stay arm, bracket tube, 9-tonne, operating rod and post insulators and in the case of sectioning insulators, the sample size shall be 2% of the quantity ordered subject to a minimum of 2 and a maximum of 10 insulators. The insulators picked up at random in accordance with the above sample size shall be equally distributed for mechanical load and mechanical performance tests given in TABLE-3.

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TABLE – 4 NUMBER OF INSULATORS (SAMPLE SIZE) TO BE SELECTED.

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Stay arm, Bracket tube, 9-Tonne and Operating rod insulators Lot size Sample size i) Less than 800 15 ii) 801 to 3200 20 iii) 3201 to 8000 25 iv) 8001 and above 30

Post insulator

Lot size Sample size i) Less than 500 15 ii) 501 to 800 25 iii) 801 and above 35

Sectioning insulator Lot size Sample size i) Less than 500 10 ii) 501 to 800 15 iii) 801 and above 25 ------------------------------------------------------------------------------------------------------------ 6.2.4 If the lot of insulators offered for acceptance tests are manufactured in more

than one manufacturing / firing schedule, then the number of insulators to be picked up at random in accordance with Clause 6.2.3 shall be proportionately distributed among the manufacturing / firing schedules giving specific serial numbers to identify the manufacturing / firing schedule and subjected to different tests as under:

6.2.4.1 Three insulators shall be visually examined and their dimensions verified. 6.2.4.2 Then all the insulators shall be treated for temperature cycle test.

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6.2.4.3 If all the insulators pass the temperature cycle test, then the number of insulators as indicated in TABLE-5 shall be tested for mechanical load and mechanical performance tests.

6.2.4.4 At least one fragment of porcelain from each of the insulators broken during

the mechanical load test and the mechanical performance test shall be tested for porosity.

6.2.4.5 At least 3 samples of each type of metal fittings from the insulators broken in

the mechanical load test and the mechanical performance test shall be tested for galvanization. In the case of stay arm insulator, at least 3 hooks shall be tested for galvanization.

6.2.4.6 At least one fragment of porcelain from each insulator broken during the

mechanical load test and the mechanical performance test shall be tested for bulk density while any one fragment of porcelain broken during the mechanical load test and the mechanical performance test shall be analyzed for chemical composition.

6.2.4.7 At least 3 insulators broken during the mechanical load test and the

mechanical performance test shall be verified in regard to eccentricity.

TABLE – 5

DISTRIBUTION OF INSULATORS FOR MECHANICAL LOAD AND MECHANICAL PERFORMANCE TESTS

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Stay arm, Bracket tube, 9-Tonne and Operating rod insulators

No. of samples Distribution

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Bending Tensile Mechanical Performance test test test -------------------------------------------------------------------------------------------------------------

15 5 5 5

20 10 5 5 25 15 5 5 30 20 5 5 --------------------------------------------------------------------------------------------------------------------------------

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Post insulator ------------------------------------------------------------------------------------------------------------ No. of samples Distribution

-----------------------------------------------------------------------------------------------------------

Bending Torsion Mechanical Performance test test test ------------------------------------------------------------------------------------------------------------

15 5 5 5 25 10 10 5 35 15 15 5 ------------------------------------------------------------------------------------------------------------ Sectioning insulator ---------------------------------------------------------------------------------------------------------- No. of samples Distribution

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Eccentric tensile Eccentric Mechanical test Performance test ------------------------------------------------------------------------------------------------------------

10 5 5 15 10 5 20 15 5 ------------------------------------------------------------------------------------------------------------ 6.2.5 ACCEPTANCE CRITERIA 6.2.5.1 If any insulator fails either in the porosity test or in the test for determination

of the bulk density, the lot shall be rejected and every insulator of the lot shall be destroyed in the presence of the Inspecting Official.

6.2.5.2 If the lot of insulators offered for acceptance tests are manufactured in more

than one manufacturing/ firing schedule and if only one insulator of any of the manufacturing/ firing schedules fails either in the mechanical load test or in the mechanical performance test, a re-test procedure shall be followed in accordance with clause 6.2.6 of this specification. If more than one insulator manufactured in a particular manufacturing/ firing schedule fails either in the mechanical load test or in the mechanical performance test or in both the tests

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taken together, then all the isolators manufactured in that manufacturing/ firing schedules shall be destroyed in the presence of the Inspecting Official. The manufacturer shall have the option to offer all the remaining insulators of the lot manufactured in the manufacturing/ firing schedules other than the one rejected and destroyed as a fresh lot again or to manufacture more insulators afresh to obtain the full lot size and then offer the insulators along with the above left over insulators as a fresh lot later. If the failure is only to hooks failing in the case of stay arm insulator (both standard and polluted zone), then all the hooks of the lot obtained by the manufacturer shall be destroyed in the presence of the Inspecting Official and the lot shall be offered again with hooks of improved quality.

6.2.5.3 Despite the insulators passing in the mechanical load test and in the

mechanical performance test, if the quality index calculated on the basis of the results of mechanical load test and mechanical performance test is less than the ACCEPTANCE CONSTANT indicated in the IEC Publication 591, the lot shall be rejected and every insulator of the lot shall be destroyed in the presence of the Inspecting Official.

6.2.5.4 If the results of test(s) other than the mechanical load test, mechanical

performance test, determination of bulk density and porosity tests, do not meet the requirements of this specification, then the balance samples shall be subjected to the particular test(s) in which it had failed. If all the remaining samples meet the requirements of the specification the lot shall be accepted.

6.2.5.5 When a lot is rejected and every insulator of the lot is destroyed in the

presence of the Inspecting Official, the procedure given in clause 6.2.7 of this specification shall also be complied with by the Inspecting Official.

6.2.6 Re-test procedure :

If only one insulator fails either in the mechanical load test or in the mechanical performance test the remaining insulators of the lot shall first be subjected to the routine mechanical load test and those insulators which do not pass the test shall be destroyed in the presence of the Inspecting Official. From out of those insulators which have passed the routine mechanical load test, a fresh sample size equal to twice the quantity indicated in clause 6.2.3 shall be picked up at random and subjected to the acceptance tests, the insulators for each test being twice that indicated in clause 6.2.3. If any failure occurs in any test including meeting the ACCEPTANCE CONSTANT indicated in IEC Publication 591, the lot shall be rejected.

6.2.7 If any lot is rejected after following the re-test procedure given in clause 6.2.6,

the insulators forming the lot shall be destroyed in the presence of the Inspecting Official. If part of the quantity of insulators manufactured during a particular manufacturing/ firing schedule has been included in forming the lot offered for acceptance tests and that the lot fails for any reason after the re-test

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procedure, then the remaining insulators of that manufacturing/ firing schedule shall be considered as suspect and therefore they shall be destroyed in the presence of the Inspecting Official, even though they are not included in the lot. Full details in regard to the rejection and destruction of insulators under this clause shall be advised to Director General (Traction Installation) Research, Design and Standards Organization, Lucknow, and the Purchaser.

6.2.8 The following shall form part of the acceptance test report. 6.2.8.1 The written consent given by the Inspecting Official in regard to the passing

of the insulators at each CHP. 6.2.8.2 A certificate by the Inspecting Official to the effect that he has checked the

records of the routine tests conducted by the manufacturer. 6.2.8.3 A statement from the manufacturer, countersigned by the Inspecting Official,

showing the rejection rate of insulators in the routine tests conducted by the manufacturer for each manufacturing/ firing schedule for the lot offered.

6.2.9 The test report shall also include the details of number of insulators

manufactured in each manufacturing/ firing schedule for the lot offered. If the lot has been formed out of insulators manufactured in more than one manufacturing/ firing schedule, then the samples to be picked up at random for acceptance tests shall be more or less equally distributed between the different manufacturing/ firing schedules. Serial numbers shall be given to the insulators to identify the manufacturing/ firing schedule from which they have been picked up and this shall also be clearly indicated in the acceptance test report.

6.2.10 A copy of the acceptance test report shall be sent immediately after

acceptance or rejection of a lot, as the case may be, to Director General (Traction Installation) Research, Design and Standards Organization, Lucknow, and the Purchaser.

6.2.11 The manufacturer shall, as far as practicable, offer the insulators manufactured

in one manufacturing/ firing schedule in one lot for acceptance tests. In case the insulators manufactured in a particular manufacturing/ firing schedule have to be divided into two lots for acceptance tests and in case one of the two lots has been accepted based upon the results of the acceptance tests while the other lot is rejected subsequently, then the insulators of the lot already accepted become suspect and therefore the manufacturer shall have to replace, free of cost, all the insulators dispatched against the accepted lot under advise to Director General (Traction Installation) Research, Design and Standards Organization, Lucknow, and the Purchaser.

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6.3 Routine Tests : 6.3.1 The following shall constitute the routine tests :

1. Routine porosity test. 2. Ultrasonic test. 3. Routine mechanical load test. 4. Visual examination.

Note : Every insulator shall pass the routine tests in the order given above. The tests shall be conducted by the manufacturer. The Purchaser shall have the right to witness routine tests. The detailed record shall be maintained of the number of insulators tested, number rejected and other essential data for the purpose of examination by the Inspecting Official. 6.3.1.1 Routine Porosity Test :

The porcelain shall have been manufactured with an extension at the top end having a diameter equal to that of the core and of length at least half the dimension of the diameter. This extension piece shall be carefully cut off and then broken into fragments. The porcelain shell and the fragments shall be marked for identification that they belong to one porcelain shell. Some fragments from the central portion of the extension shall be tested for porosity as per clause 6.1.5.11. If any of the fragments so tested shows porosity, the porcelain shell from which the fragments were obtained shall be rejected and destroyed. If none of the fragments shows any porosity, then the porcelain shell from which the fragments have been obtained shall be considered as having passed the test. Such porcelain shells shall be affixed with a clear label or stamp on the glazed portion so as not to be covered by the metal fittings.

6.3.1.2 Ultrasonic Test : This test shall be made on every porcelain shell after the extension piece required for routine porosity test has been cut off, the ends of the shell machined and prior to fitment of the metal fittings. Using a suitable ultrasonic testing equipment which can produce ultrasonic waves of frequency between 0.8 and 5 MHz and the speed of propagation of the waves not less than 5800 m/s, the porcelain shell shall be tested both in the longitudinal direction as well as in the transverse direction using appropriate probes. There shall be no defective echo between the initial echo and the back wall echo and the amplitude of the back wall echo shall be equal to the initial echo. Any porcelain shell which does not comply with this acceptance criteria and shows cracks or internal flaws of any nature shall be rejected and destroyed. The test may be repeated on the insulators after fitment of the metal fittings. Every insulator passing in the ultrasonic test shall be affixed with a clear label or stamp on the glazed portion so as not to be covered by the metal fittings.

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6.3.1.3 Routine Mechanical Load Test :

All insulators except for sectioning insulator shall be subjected to axial tensile load of 60% of the value specified in TABLE-3. In the case of sectioning insulator, the tensile load shall be applied eccentric as indicated in clause 6.1.5.8.3. If any insulator cracks or its metal fittings loosen or deform or crack, it shall be rejected. If the metal fitting gets marked at the locations where they are connected to the fixtures in the testing machine / mechanism, such marks shall not be regarded as deformations. Every insulator passing in the routine mechanical load test shall be affixed with a clear label or stamp on the glazed porcelain so as not to be covered by the metal fittings

6.3.1.4 Visual Examination :

The visual examination shall be conducted as per clause 6.1.5.1. 7. INFORMATION TO BE GIVEN BY THE TENDERER 7.1 The tenderer shall furnish along with his offer, the schedule of Guaranteed

Performance, Technical and Other Particulars (SOGP) in the proforma at Appendix-“C”, for each type of insulator. The particulars shall be correct and complete in all respects. If there is any entry like “shall be furnished later” or a blank is left against any item, the offer is not likely to be considered as the evaluation of the offer is rendered difficult as it cannot be compared with other offers, if any.

7.2 The tenderer shall specifically indicate in a “Statement of Compliance” attached with

the offer his compliance with each and every clause of this specification. In case the tenderer wishes to deviate from any clause of this specification he may do so giving reference to the clause(s) with the reason / justification for the deviation. This shall be in the form of a separate statement called the “Statement of Deviations”. If there is no deviation at all, a specific “Nil” “Statement of Deviations” shall be attached with the offer. If the “Statement of Compliance” and “Statement of Deviations” are not attached with the offer, it is not likely to be considered for the reason that it is an incomplete offer which cannot be properly evaluated and compared with other offers, if any.

7.3 The tenderer / manufacturer shall also furnish the following information with the

tender bid : 7.3.1 A detailed drawing indicating all dimensions of the insulator and showing also the

actual creepage distance, guaranteed electrical and mechanical particulars and other parameters of the insulator profile in accordance with IEC Publication 815.

7.3.2 A detailed drawing indicating all dimensions of the porcelain shell including every

dimension of shed profile, spacing, creepage distance and type of porcelain.

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7.3.3 A detailed drawing of each of the metal fittings indicating the internal angle and all other dimensions.

7.3.4 Details of the manufacturing process, the Quality Assurance Plan being adopted and

other facilities including testing facilities available at the tenderer’s / manufacturer’s works.

7.3.5 Micrographs of the porcelain, results of petrographic tests of materials proposed for

the porcelain of the insulators and results of autoclave test for compatibility of glaze with the porcelain.

7.3.6 A note describing the salient features of the design of the insulators, profile of the

sheds of the porcelain shell and the jointing process between porcelain shell and metal fittings.

8. PACKING 8.1 The insulators shall be securely packed in wooden crates. Not more than two

insulators shall be packed in a crate so as to facilitate manual loading and un-loading by one person.

9. AFTER SALES SERVICE 9.1 The manufacturer shall make necessary arrangements for closely monitoring the

performance of the insulators through periodical (preferably once in two months) visits to the offices of the consignees to whom they have been dispatched for interaction with the operating and maintenance personnel of the Indian Railways.

9.2 The manufacturer shall respond promptly and in a workman like manner to any call

given by Indian Railways for any assistance by way of attending to failures, investigation into the causes of the failures including tests, if any, to be done and such other items with a view to seeing that the insulator serves the purpose for which it is intended.

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APPENDIX “A”

CORRECTION OF TEST VOLTAGES FOR ATMOSPHERIC CONDITI ONS

A – 1. GENERAL A – 1.1 Variation in barometric pressure and humidity of the atmosphere cause

variation in the electric strength of the air and hence in the flashover voltage of an insulator exposed to atmosphere.

A – 2. CORRECTION FACTORS A – 2.1 When the atmospheric conditions around an insulator during test differ from

the reference conditions, adjustments are required to be made to certain of the test voltages by the application of the following correction factors in accordance with TABLE A-1 at the end of this Appendix.

(a) Correction factor (d) for air density: 0.289 p

d = ------------ (d lies between 0.95 and 1.05) 273 + t where p = atmospheric pressure in mbar, and t = temperature in °C

For a wider range of density and for higher accuracy, the factor k shall be used instead of factor d. The values of factor k corresponding to various values of factor d are given below :

d k ------- -------- 0.70 0.72 0.75 0.77 0.80 0.82 0.85 0.86 0.90 0.91 0.95 0.95 1.00 1.00 1.05 1.05 1.10 1.09 1.15 1.13

123

(b) Correction factor (h) for humidity : Figure A-1 attached gives the values of absolute humidity value for wet and dry bulb temperatures (when the velocity of air over the wet bulb exceeds 3 m/s) for the standard atmospheric pressure of 1013 mbar. For better accuracy, a correction should be applied to the absolute humidity value obtained from Figure A-1 for any deviation of ambient atmospheric pressure from the standard value of 1013 mbar. This correction is obtained from Figure A-2 as follows:

Locate the point corresponding to the deviation of ambient atmospheric pressure from 1013 mbar on the left hand side of Figure A-2B and join it with the right hand side top corner by a straight line. Then locate the point on the curve in Figure A-2A corresponding to the observed value of the difference of dry and wet bulb temperatures. Draw a vertical line through this point to intersect the straight line drawn in Figure A-2B. Read the correction to be applied to humidity from the right hand side of Figure A-2B corresponding to the point of intersection. The correction is positive for a positive deviation and negative for negative deviation from the standard atmospheric pressure. For the corrected value of absolute humidity thus obtained, the correction factor (h) of TABLE A-1 shall be determined from Figure A-3.

TABLE A-1

CORRECTION OF VOLTAGES FOR ATMOSPHERIC CONDITIONS .

TYPE OF TEST ----------------------

ADJUSTMENT REQUIRED ------------------------------------

Dry lightning impulse withstand voltage

Voltage applied shall be the appropriate value specified in TABLE – 2 multiplied by k and divided by h.

Wet power frequency withstand voltage

Voltage applied shall be the appropriate value specified in TABLE – 2 multiplied by k.

Wet power frequency maximum withstand voltage

Measured voltage shall be divided by k.

124

APPENDIX “B”

HIGH VOLTAGE TESTS

B – 1. ARRANGEMENT OF INSULATOR B – 1 – 0 GENERAL - The insulator shall be clean and dry and in thermal

equilibrium with its surroundings. B – 1.1 Insulators tested in vertical position : B – 1.1.1 The insulator shall be hung vertically from an earthed support by means of a

wire rope or metal rod. The distance between the top of the insulator metal fitting and the point of support shall be less than 1m. At the lower end of the insulator shall be attached, if required, a metallic rod of weight adequate to ensure that the insulator remains in vertical position during test.

B – 1.1.2 No object shall be nearer to the axis of the insulator than 1 m or 1.5 times the

length of the insulator whichever is the greater. B – 1.1.3 The test voltage shall be applied between the metal rod at the bottom of the

insulator and the earthed point of suspension. B – 1.2 Insulators tested in horizontal position : B – 1.2.1 The insulator shall anchored by means of a cable or metal rod connected to

earth. The distance between the top of the insulator metal fitting and the point of anchorage shall be less than 1m.

B – 1.2.2 The other end of the insulator shall be provided with a metal rod about 1 m long and the whole arrangement maintained in an approximately horizontal position by any convenient means.

B – 1.2.3 No object shall be nearer to the axis of the insulator than 1 m or 1.5 times the

length of the insulator whichever is the greater. B – 1.2.4 The test voltage shall be applied between the end of the metal rod and the

earthed point of anchorage. B – 2 HIGH VOLTAGE TEST B – 2.1 The high voltage test shall be conducted in accordance with IS:2071 (Part I to III).

125

B – 3 PRECAUTIONS AGAINST EXCESSIVE HUMIDITY B – 3.1 Special precautions shall be taken to avoid condensation on the surface of the

insulator when the relative humidity is high. For example, the insulator shall be maintained at the ambient temperature at the test location for a sufficient period to attain thermal equilibrium before commencing the test. Except by agreement between the manufacturer and the purchaser, the test shall not be made if the relative humidity exceeds 85%.

126

APPENDIX “C”

Appendix to Specification No. ETI/OHE/15 (9/91)

SCHEDULE OF GUARANTEED PERFORMANCE TECHNICAL AND OTHER PARTICULARS.FOR SOLID CORE PORCELAIN INSU LATORS

FOR 25 kV, AC, 50 Hz, SINGLE PHASE OVERHEAD TRACTION LI NES

S.No Description Unit of measurement

1. Name of manufacturer

2. Country of origin

3. Standard specification on which performance data is based

4. Manufacturer’s type designation

5. Type of porcelain

6. Bulk density For test specimen For insulator

g/cm2 g/cm2

7. Flexural strength of test specimen Unglazed Glazed

MPa MPa

8. Modulus of elasticity of test specimen

GPa

9. Creepage distance (minimum guaranteed)

mm

10. Grade and specification of metal fittings.

11. Mass of zinc coating of metal fittings.

g/cm2

12. Rated voltage

KV

13. Corona initiation voltage

kV (rms)

14. Corona extinction voltage

kV (rms)

15. Dry lightning impulse withstand voltage

kV (peak)

127

16. Wet power frequency withstand voltage.

kV (rms)

17. Wet power frequency maximum withstand voltage

kV (rms)

18. Maximum value of Equivalent Salt Deposit Density (ESDD) at 30 kV (rms)

mg/cm2

19. Minimum tensile breaking load (eccentric tensile in case of sectioning insulator)

kgf

20. Minimum breaking bending moment

kgf.m

21. Minimum breaking torsional moment

kgf.m

22. Ultimate tensile breaking load (eccentric tensile in case of sectioning insulator)

kgf

23. Ultimate breaking bending moment

kgf.m

24. Ultimate breaking torsional moment

kgf.m

25. Sequence of power arc test offered

26. Tensile and bending strength after completion of power arc test.

kgf / kgf.m

27. Frequency of ultrasonic wave

MHz.

28. Speed of propagation of ultrasonic wave obtained

m/s

29. Weight of unit kg

128

ADDENDUM & CORRIGENDUM SLIP NO. 1 to RDSO’s Specification No. ETI/OHE/15 (9/91)

for “Solid core porcelain insulators for 25 kV AC, 50 Hz, Single phase

overhead traction lines”. Para 4.1.4 Delete the entire para and rewrite as given below:

The minimum alumina content shall be 45%. No quartz powder shall be added as raw material. The values of essential ceramic properties of the insulator are indicated in the Table - 1.

TABLE –1 CERAMIC PROPERTIES

Property Value

i)

Bulk density 2.60 g/cm3 (minimum) on test specimen. 2.50 g/cm3 (minimum) on fired porcelain.

ii)

Modulus of elasticity 105 Gpa (minimum)

iii) Flexural strength Unglazed Glazed

140 Mpa (minimum) 160 Mpa (minimum)

Para 4.3.1 Delete Table – 3 of para 4.3.1 and rewrite as follows:

TABLE –3 MINIMUM MECHANICAL FAILING LOADS AND

BENDING AND TORSIONAL MOMENTS

Type of insulator Tension (kgf)

Tension with 80 mm eccentricity of

load (kgf)

Bending moment (kgf.m)

Torsional moment (kgf.m)

Stay arm 7000 --- 200 --- Bracket tube 7000 --- 200 --- 9-tonne 9900 --- 210 --- Operating rod 2200 --- 70 --- Post 6000 --- 370 550 Sectioning --- 5000 --- ---

Para 6.1.3.1 (g) Delete the words “Visual examination and”.

129

Para 6.1.5 (vii) Add the following :

If the facility for conducting this test on glazed test specimen is not available, the test shall be conducted on insulators as per DIN 40658 Part II.

Para 6.1.5.1 Delete the entire para and rewrite as follows :

The insulator shall be visually examined to see that it is free from physical distortion of shape and that the vitrified glaze is hard and smooth and the surface is free from cracks or any other defect likely to be prejudicial to satisfactory performance in service. The cement for jointing shall be finished flush with the edge of the metal fittings and in any case shall not project more than 2 mm above the edge. The exposed surface of the cement shall not show any sign of crack or blow hole. The metal fittings shall be smooth without any excrescence. Before accepting the lot for tests, each insulator shall be checked for the following defects in case of type tests and 15% of the lot of insulators shall be checked for these defects in case of acceptance tests.

3 Glaze Defects – The glaze defects shall not exceed the limits permissible for the

appropriate class of the insulator as specified in JIS-C-3802.

4 Tilt, Mis-alignment and Threads of Metal Fittings – Generally no tilt of metal fitting is acceptable for all types of insulators. However, a maximum tolerance of 2 mm for the tilt of metal fitting shall be permitted if the tilt could not be avoided totally. Wherever thread cutting is required in the metal fittings, each insulator shall be checked for the diameter of thread and depth of threaded portion as per the specification / approved drawing using suitable gauges. The mis-alignment shall be checked for each isolator separately for the following types of insulators as detailed below:

(a) Stay arm insulator : i) Tube side metal fitting : Each insulator shall be checked for the

diameter of transverse holes and the distance between the transverse holes as well as from the ends of metal fittings using suitable gauges.

ii) Stay arm insulator hook : Each hook shall be checked for the diameter

of thread and length of the threaded portion as per specification using suitable Go and No Go gauges.

(b) Bracket insulator :

i) Tube side metal fitting : Each insulator shall be checked for the

machining of the hole as per the specification using suitable gauge and U bolts.

(c) Sectioning insulator :

130

Each metal fitting shall be checked for the critical dimensions of the metal fittings using suitable gauges. The insulators which do not comply with the requirements of the specification / approved drawings in case of the above defects shall be rejected and destroyed in presence of the inspecting official. The details of rejection such as batch number and quality shall form part of the type / acceptance reports.

Para 6.1.5.8.1 In the 5th line correct existing “60%” as “70%”. Para 6.1.5.8.2 In the 9th line correct existing “60%” as “70%”. Para 6.1.5.8.3 In the 9th line correct existing “60%” as “70%”. Para 6.1.6.3 Add new para :

The results of failing bending moment in mechanical load test shall be computed for (X-3) and this value shall not be less than the specified minimum failing bending moment.

Para 6.2.1.2 Add new para :

The visual examination shall be conducted as per clause 6.1.5.1 on 15% of the lot offered and then other acceptance tests shall be conducted on the samples selected from the lot for conducting acceptance tests. If any failure occurs, a further quantity of 30% of the lot shall be visually examined. If any insulator fails in the retest, the entire lot shall be rejected.

Para 6.2.1.3 Add new para :

The lot offered shall be considered for acceptance tests only after the lot has been inspected and cleared of CUSTOMER HOLD POINTS indicated in the approved Quality Assurance Plan of the manufacturer.

Para 6.2.4.1 Rewrite as follows : The dimensions of three insulators shall be verified. Para 6.2.5.1 Delete the entire para and rewrite as follows :

If any insulator fails either in the porosity test or in the test determination of the bulk density or in the minimum percentage of alumina content, the lot shall be rejected and every insulator of the lot shall be destroyed in the presence of the Inspecting Officer.

131

Para 6.2.5.4 The existing para 6.2.5.4 to be renumbered as 6.2.5.5 and the following shall

form para 6.2.5.4 :

The results of failing bending moment in mechanical load test shall be computed for (X-3 ) and this value shall not be less than the specified minimum failing bending moment.

Para 6.2.5.5 Renumber as 6.2.5.6. Para 6.2.10 Delete the entire para and rewrite as follows :

A copy of the acceptance test report shall be sent immediately by the manufacturer after acceptance or rejection of a lot as the case may be, to Director General (Traction Installation), Research Designs and Standards Organization, Lucknow and the Purchaser.

Para 6.3.1.3 Delete the entire para and rewrite as follows : Routine Mechanical Load Test:

All insulators except for sectioning insulator shall be subjected to axial tensile load of 70 % of the value specified in Table-3. In the case of sectioning insulator, the tensile load shall be applied eccentric as indicated in clause 6.1.5.8.3. If any if any insulator cracks or its metal fittings loosen or deform or crack, it shall be rejected. If the metal fitting gets marked at the locations where they are connected to the fixtures in the testing machine / mechanism, such marks shall not be regarded as deformations. Every insulator passing in the routine mechanical load test shall be affixed with a clear label or stamp on the glazed porcelain so as not to be covered by the metal fittings.

Para 6.3.1.4 Delete the entire para and rewrite as follows :

The visual examination shall be conducted on each insulator as per clause

Encl: Nil Lucknow – 226 011, Dated : 24-05-99.

132

ADDENDUM & CORRIGENDUM SLIP NO. 2

to RDSO’s Specification No. ETI/OHE/15 (9/91) for “Solid core porcelain insulators for 25 kV AC, 50 Hz, Single phase

overhead traction lines”. Para 4.1.2 Delete the second sentence and rewrite as given below:

All the six types of insulators for Normal zone and the three types of insulators for Polluted zone shall be manufactured with aluminous porcelain only and they shall be fired in shuttle kiln only with precise temperature control.

Para 4.1.11 Delete the second sentence and rewrite as given below :

The jointing process shall be done by a mechanized method and care shall be taken to ensure that the porcelain shell and the metal fittings are properly aligned and that no part of the porcelain shall come in direct contact with the metal fittings.

Para 6.3.1 Add the following as Sl. No. 3 Routine temperature cycle followed by wooden mallet test. Renumber Sl. No. 3 and 4 as Sl. No. 4 and 5. Para 6.3.1.2 Add the following in the ninth line after the words “using appropriate probes” The ultrasonic test in the longitudinal direction shall be done on both sides. Para 6.3.1.3 Add the new para

The routine temperature cycle test shall be conducted as per clause 6.1.5.7 on each shell manufactured. The number of heating and cooling cycle shall be three and the period of immersion in hot and cold bath shall be 15 minutes. After completion of the routine temperature cycle test, each shell shall be subjected to a wooden mallet test on both ends. The insulators which fail in this test shall be rejected and destroyed. Every insulator passing in the routine temperature cycle test shall be affixed with a clear label or stamp on the glazed portion so as not to be covered by the metal fittings.

Para 6.3.1.3 Renumber as 6.3.1.4 Para 6.3.1.4 Renumber as 6.3.1.5

---------------- :o:---------------- Encl: Nil Lucknow – 226 011, Dated : 04-02-2000.

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overhead traction lines”. Para 6.2.1.2 Add the new para

The acceptance tests shall be conducted by the authorized representative of the Director General (Traction Installation), Research Designs and Standards Organization, Lucknow. The manufacture shall combine different orders for different types of insulators placed on him and plan to offer the lots for acceptance tests by RDSO for not more than five times in a year.

Para 6.2.2 Delete the entire para and rewrite as follows: CUSTOMER HOLD POINT.

During the development of prototype as per this specification, the manufacturer shall furnish the Qquality Assurance Plan to Director General (Traction Installation), Research Designs and Standards Organization, Lucknow who shall indicate in the Quality Assurance Plan the CUSTOMER HOLD POINT / POINTS (CHP) beyond which the next step in the manufacturing process will not be taken up. The lot size to be offered for the acceptance tests shall be decided by the manufacturer as per guidelines given in clause 6.2.1.2. The Inspecting Official shall pick up at random a minimum of 5% of the lot offered and conduct the test prescribed for clearance of the CHP. If the samples pass the test, the Inspecting Official shall give written permission to the manufacturer to proceed with the next step in the manufacturing process. This written permission shall form part of the acceptance test report. This procedure shall be repeated for each CHP. If during the test for CHP the sample fails, the manufacturer shall be advised in writing by the Inspecting Official. The manufacturer shall rectify the defect and offer the insulators again for tests. This written advise will also form part of the acceptance test report. A distinct numbering shall be given to identify the manufacturing / firing schedule. The format of the report on CHP, framed by Director General (Traction Installation), Research Designs and Standards Organization, Lucknow, shall be followed.

Para 6.2.2.1 Add the new para

The validity of the approval of QAP shall be till the validity of the prototype approval accorded. Whenever the extension of the approval of prototype is sought or whenever a repeat prototype test is conducted, as the case may be, the QAP shall be submitted by the manufacturer for approval of RDSO.

134

Para 6.2.2.2 Add the new para

The tests for clearance of each CHP shall be conducted by the authorized representative of Director General (Traction Installation), Research Designs and Standards Organization, Lucknow during the manufacture of insulators. After clearance of all the CHPs indicated in the QAP, the acceptance tests shall be conducted by the authorized representative of Director General (Traction Installation), Research Designs and Standards Organization, for accepting the lot as mentioned in para 6.2.1.2 above.

---------------- :o:---------------- Encl: Nil Lucknow – 226 011, Dated : 29-02-2000.

135



overhead traction lines”. Para 6.1.5 Add the following test at S.No.19

Analyses by X-Ray Diffractomery (XRD) and Scanning Electron Microscopy and Energu Dispensive X-Ray Analysis IM & EDXA) Add under Note at S.No.(xi) as under These analyses shall be conducted on one insulator broken in the mechanical load and mechanical performance tests. Three pieces of porcelain out of the insulator selected will be sealed by the Inspecting Official One sealed Piece will be sent to the Independent Organisation/ Institution for conducting the test and submitting the report. One sealed piece shall be retained by the manufacturer and one sealed piece shall be retained at RDSO.

Para 6.1.5 19 Add New Para XRD and SEM & FDXA Analyses

Atleast three fragments will be taken from the pofeclain piece sealed for the purpose of conducting XRD and SEM & EDXA analysis. Each fragment shall be individually subjected to the above analyses. Resulting to be based on the values obtained during the analysis at live different on each fragment and reported as aggregate or range for each SEM & EDXA Analysis : By this method, the Microstructure and Chemical composition analysis will be made and the following will be evaluated. i) Total % A/203 (Alumina ) ii) Percentage impurities viz. Fe203, DO2, CaO iii) Percentage of Mulhte & other Alumino Silicates iv) licrostructural Details For Free Alumina in glassy matrix, parosify, defects and for variation in composition between different regionsin the glassy matrix apart from the free alumina phase. XRD Analysis By this method, the followings will be evaluated j) Percentage free a – Alumina (Corundum Phase ) ii) Percentage free a – Quartz (Quartz Phase )

136

Para 6.1.6.4 Add New Para

No Acceptance Criteria has been specified at present for the results of XRD and SEM & EDXA analysis. Data will be accumulated and after study of sufficient data the limiting values shall be specified.

Para 6.2.1 Add the following test at S.No.11

11. Analyses by X-Ray Diffractometry (XRD) and Scanning Electron Microscop and Energy Dispensive X-Ray Analysis (SEM & EDXA ).

Para 6.2.3.1 Add New Para

The sample size for conducting XRD and SEM & EDXA analysis will be atleast one insulator for every 1000 insulators or part thereof offered for CHP clearance. The insulators shall be selected normally from the firing cycles in which large number of insulators have been fired. Three pieces out of each insulator selected will be sealed by the Inspecting Official One sealed piece will be sent to the Independent Organisation/Institution for conducting the test and submitting the report. One sealed piece shall be retained by the manufacturer and one sealed piece shall be retained at RDSO. The results of the analyses shall be submitted while offereing the assembled insulators for final inspection. The authority for issue of Inspectiion Certificate for the Final Inspection without the receipt of the results of the analyses shall be with Director General/TI, RDSO, Lucknow.

Para 6.2.5.7 Add New Para as below :

No Acceptance Criteria has been specified at present for the results of XRD and SEM & EDXA Analysis. Data will be accumulated and after study of sufficient data the limiting values shall be specified.

…………..

137

ADDENDUM & CORRIGENDUM SLIP NO. 5

to RDSO’s Specification No. ETI/OHE/15 (9/91) FOR “Solid core porcelain insulators for 25 kV AC, 50 Hz, Single phase

overhead traction lines”. 4.1.9 Replace contents of entire para with contents as below :

4.1.9 Metal fittings shall be made of black heart malleable cast iron conforming to Grade BM : 340 of IS : 2108 or spheroidal graphite cast iron to Grade :400/12 of IS:1865 or Forged steel fittings to BS-970(Part-II). Approval of the type test of an insulator implies employment ofmetal fitting of the particular insulator implies employment of metal fitting of the particular make & design approved during type test. In event of insulator manufacturer employing alternate material or make of metal fitting all prototype test will be required to be repeated.

In addition to the above, RDSO may carry out the checks on incoming metal fittings. Para 6.2.1 Delete S.No.11 Para 6.2.1.2 Delete the entire para Para 6.2.2 Replace contents of entire para with contents as below : 6.2.2 CUSTOMER HOLD POINT 1.0 Stage inspection at CUSTOMER HOLD POINT (CHP) for shells and metal fittings

will not be carried out for insulators manufactured by sources appearing in Part-I category of RDSO’s list of approved vendors. This clause is to be read in conjuction with clause 6.2.3(b)

1.1 For insulators from Part-II sources, CHP will be conducted by the nominated Inspecting agency. 2.0 For CHP inspection, the inspecting official shall pick up at ramdom a minimum of

5% of the lot offered and conduct the test prescribed for clearance of the CHP. If the samples pass the test, the Inspecting official shall give written permission to the manufacturer to proceed with the next step in the manufacturing process. This written permission shall form part of the acceptance test report. This procedure shall be repeated for each CHP. If during the test for CHP the sample fails, the manufacturer shall be advised in writing by the Inspecting official. The manufacturer shall rectify the defect & offer the insulators again for test. This written advise will also form part of the acceptance test report. A distinct numbering shall be given to identify the manufacturing/ firing schedule. The format of the

138

report on CHP, issued by Director General (Traction Installation), Research Designs and Standards Organisation, shall be followed.

Para 6.2.2.1 Replace contents of entire para with contents as below :-

Para 6.2.2.1 Prototype approval shall be accorded for a period of 12 months only. Thereafter

extensions for periods of 12 months may be tranted on application by the manufacturer. The approval of QAP shall also be valid till the expiry of the prototype approval. Whenever an extension of the approval of prototype is sought of whenever a repeat prototype test is conducted, the QAP shall be submitted by themanufacturer for approval of RDSO.

In addition a quality audit shall be done minimum twice a year for checking quality of

the manufacturing/process”. Para 6.2.2.2 Delete the entire para. Para 6.2.3 Replace contents of entire para with contents as below : “ Sampling Plans shall be as under : (b) When CHP inspection is required to be carried out, the sampling plan will be as per

Table 4A and as under.

The number of insulators (sample size) to be picked up at ramdom (by any random number generation method ) from the lot offered for acceptance tests as tabulated below :

NOTE :- If the order is for a smallquantities, the sample size shall be 3% of the quantity ordered subject to a minimum of 3 and a maximum of 15 insulators in case of stay arm, bracker tube, 9-tonne, operating rod and post insulators and in the case of sectioning insulator, the sample size shall be 2% of the quantity ordered subject to a minimum picked up at ramdom in accordance with the above sample size shall be equally distributed for mechanical load and technical performance tests given in TABLE-5.

TABLE-4A NUMBER OF INSULATORS (SAMPLE SIZE) TO BE SELECTED

Stay arm, Bracket tube, 9-Tonne and Operating rod insulators

Sl.No. Lot size Sample size i Less than 800 15 ii 801 to 3200 20 iii 3201 to 8000 25 iv 8001 and above 30

139

Post Insulator

Sl.No. Lot size Sample size i Less than 500 15 ii 501 to 800 25 iii 801 and above 35

Sectioning Insulator

Sl.No. Lot size Sample size i Less than 500 10 ii 501 to 800 15 iii 801 and above 25

(b) For Regular (Part-I) sources, where CHP inspection is not required to be carried out,

the sampling plan will be as per Table 4B, as under. The number of insulators (sample size) to be picked up at random (by any random

number generation method) from the lot offered for acceptance tests shall be in accordance with the TABLE-4B.

TABLE-4B NUMBER OF INSULATORS (SAMPLE SIZE) TO BE SELECTED

Stay arm, Bracket tube and 9-Tonne Insulators.

Sl.No. Lot size Sample size i Less than 800 20 ii 801 to 3200 25 iii 3201 to 8000 30 iv 8001 and above 35

Post Insulator and Operating rod insulators

Sl.No. Lot size Sample size i Less than 500 5%(Min. 6Nos. & Max. 25 Nos.) ii 501 to 800 35 iii 801 and above 45

Sectioning Insulator

Sl.No. Lot size Sample size i Less than 500 3%(Min. 4 Nos. & Max. 15 Nos.) ii 501 to 800 25 iii 801 and above 35

6.2.3.1 Delete the entire para. 6.2.4.7 Replace contents of entire para with contents as below :

140

Atleast 3 Insulators broken during the mechanical load test and the mechanical performance test shall be verified in regard to eccentricity.

TABLE-5

DISTRIBUTION OF INSULATORS FOR MECHANICAL LOAD AND MECHANICAL PERFORMANCE TEST

Stay arm, Bracket tube & 9-Tonne

No. of Samples Distribution

Develop mental

Regular Bending Test Tensile Test Mechanical Performance

test Develop mental

Regular

15 20 5 10 5 5 20 25 10 15 5 5 25 30 15 20 5 5 30 35 20 25 5 5

Post Insulator and Operating rod Insulators.

No. of Samples Distribution Develop mental Regular

Bending Test Torsion for Post) or Tensile (for Operating

rod) Test

Mechanical Performance

test

Develop mental

Regular Develop mental

Regular

15 25 5 10 5 10 5 25 35 10 15 10 15 5 35 45 15 20 15 20 5

Sectioning Insulator :

No. of Samples Distribution Eccentric Tensile Test Eccentric Mechanical

Performance Test

Develop mental



Regular

10 15 5 10 5 5 15 20 10 15 5 5 20 25 15 20 5 5

Para 6.2.5.3 Replace contents of entire para with contents as below :

Despite the insulators passing in the tensile load test and in themechanical performance test, if the quality index calculated on the basis of the results of tensile load test and mechanical performance test is less than the

141

ACCEPTANCE CONSTANT indicated in the IEC Publication 591, the lot shall be rejected and every insulator of the lot shall be destroyed in the presence of the Inspecting Official.

6.2.5.3.1 Add new Para Despite the Insulators passing in the bending moment test, if the value of X-

3on-1 is not achieved, the lot of insulators shall be destroyed in the presence of the Inspecting Official.

Para 6.2.6 Replace contents of entire para with contents as below :- Re-Test Procedure :

If only one insulator fails either in the tensile load test or in the mechanical performance test the remaining insulators of the lot shall first be subjected to the routine tensile load test and those insulators which do not pass the test shall be destroyed in the presence of the inspecting Official. From out of those insulators which have passed the routine tensile load test, a fresh sample size equal to twice the quantity indicated in clause 6.2.3 shall be picked up at random and to the acceptance tests, the insulators for each test being, twice that indicated in clause 6.2.3. If any occurs in any test including meeting the ACCEPTANCE CONSTANT indicated in IEC Publication 591, the lot shall be rejected.

Para 6.2.6.1 Add new para

If only one insulator fails in the beinding moment test, the remaining insulators of the lot shall first be subjected to the routine bending moment test at 70% of the specified load and those insulators which do not pass the test shall be destroyed in the presence of the Inspecting Official. From out of those Insulators which have passed the routine bending moment test, a fresh sample size equal to twice the quantity indicated in clause 6.2.3 shall be picked up at random and to the acceptance tests, the insulators for each test being twice that indicated in clause 6.2.3.

If more than one insulator failed in bending moment test lot shall be destroyed in the presence of the Inspecting Official. However, if all insulators passed, but the value of X-3on-1 not achieved the whole lot shall be destroyed in the presence of the Inspection Official.

6.2.12 Add New Para

The manufacturer shall offer for acceptance tests of batches/firing cycle same or dated later but not of those batches which are prior to the last inspected lot.

……….. Encl : Nil Lucknow – 226011 Dated 01.09.2004

142

143

144

145

146

147

148

149

150

151

152

153

154

155


SPECIFICATION

FOR

220kV OR 132kV OR 110kV OR 66kV OR 25kV

POTENTIAL TRANSFORMERS

NO.TI / SPC / PSI / PTs / 0990

156

MAY 2003

SPECIFICATION NO. TI / SPC / PSI / PTs / 0990


RESEARCH DESIGNS AND STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW – 226011


FOR

220kV OR 132kV OR 110kV OR 66kV OR 25Kv

POTENTIAL TRANSFORMERS

ISSUED BY


MANAK NAGAR, LUCKNOW 226011

157

ANNEXURES

ANNEXURE-1

DRAWING FOR GENERAL SCHEME OF POWER SUPPLY FOR TRACTION SUBSTATION.

ANNEXURE-2

TERMINAL CONNECTOR FOR PRIMARY SIDE (RIGID TYPE)

ANNEXURE-3

TITLE FORMAT SHEET FOR DRAWINGS.

ANNEXURE-4

SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND OTHER PARTICULARS.

ANNEXURE-5

TERMINAL PLATE DETAIL

ANNEXURE-6

LIST OF ABBREVIATION

158

Specification No. TI/SPC/PSI/PTs/0990

POTENTIAL TRANSFORMERS, 220kV or 132kV or 110kV or 66kV or 25kV.

1.0 SCOPE 1.1 This specification applies to outdoor type single phase, oil immersed 220kV or

132kV or 110kV or 66kV or 25 kV (Type I & II) Potential Transformers (PT) to be installed at unattended / attended railway traction substations / switching stations for operation of protective devices, metering and indication.

1.2 The potential transformers shall be complete with all parts and accessories necessary

for their efficient operation. All such parts and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not.

1.3 This specification supersedes the earlier specification no. ETI/PSI/35 (4/75),

ETI/PSI/56 (3/80) and ETI/PSI/08 (10/92) which was meant for 132kV, 66kV and 25 kV potential transformers respectively, while this specification has been prepared to cater the need of potential Transformer for system voltages of 220kV, 132kV, 110 kV, 66kV or 25 kV latest modification / test suggested by IS : 3156-1992 have been incorporated in this specification. Hence, the equipment approved (includes prototype approval) as per either of these above superseded specifications, shall be considered as approved as per this specification also. This specification is a combined specification for all type of PTs, used in traction distribution system.

1.4 The PT shall be erected by the purchaser / Indian Railways. However, in case a defect

/ deficiency noticed, the manufacturer / successful tenderer, will have to depute his engineer for necessary remedial action without any cost to the Railways.

2. SERVICE CONDITIONS 2.1 The potential transformers are intended for use in normally polluted moist tropical

climate and in areas subject to heavy rain and lightning in India. The maximum ambient temperature may reach 50 °C in shade, the daily maximum average ambient in shade reaching 40 °C, with maximum humidity upto 100%.

2.2 The potential transformers are required to be used for connection between phase

conductors and earth of a 220 or 132 or 110 or 66 or 25 kV three phase or one phase system with neutral effectively earthed, for operation of protection schemes and for connection to metering / indicating instruments.

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3. GOVERNING SPECIFICATION 3.1 In the preparation of this specification assistance have been derived from the

following standards and codes of practices (latest version) and Indian Electricity Rules, wherever applicable:

1. IS : 5-1994 : Colours for ready mixed paints and enamels

2. IS : 335-1993 : New insulating oils

3. IS : 2062-1992 : Specification for structural steel (Standard quality).

4. IS : 1271-1985 : Classification of insulating materials for electrical

machinery and apparatus in relation to their thermal stability in service.

5. IS : 1367-1996 : Technical supply conditions for threaded steel

fasteners.

6. IS : 1570-1991 : Stainless and heat resisting steels.

7 IS : 1554 (Pt I)-1988 : Specification for PVC insulated (Heavy duty) electrical cables for working voltage upto and including 1100 volts.

8. IS : 1866-1991 : Code of practice for maintenance and supervision of

mineral insulating oil in the equipment. 9. IS : 3024-1996 : Specification for electrical steel sheets (oriented). 10. IS: 3156-1992 : Specification for Voltage transformer (Part 1 to 4) 11. IS : 4253 (Pt II)-1989 : Cork and Rubber 12. IS: 5561-1992 : Specification for Electric Power connectors 13. IS : 5621-1988 : Specification for hollow insulator for use in

electrical equipments. 14. IS : 9224-1993 : Specification for low voltages fuses. (Part I & II) 15. IS : 10028-1991 : Code of practice for selection, installation and

(Part I to III) maintenance of transformer.

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16. IS : 11322-1990 : Method of Partial discharge measurement in instrument transformer.

3.2 In case of any conflict between the contents of the above specifications and this

specification, the latter shall prevail. 3.3 Any deviation from this specification, to improve the performance, utility and

efficiency of the equipment, proposed by the Tenderer, will be given due consideration, provided full particulars with justification thereof, are furnished.

4. ENVIRONMENTAL CONDITIONS

4.1 The Potential Transformer shall be suitable for outdoor use in moist tropical climate

and in areas subject to heavy rainfall, pollution due to industry and saline atmosphere and severe lightning. The limiting weather conditions which the transformer has to withstand in service are indicated below:

i) Maximum ambient air temperature 50 °C. ii) Average ambient air temperature over 40 °C. a period of 24 hours. iii) Maximum relative humidity 100 % iv) Annual rainfall Ranging from 1750 mm to

6250 mm.

v) Maximum number of thunder storm 85 days per annum.

vi) Maximum number of dust storm 35 days per annum.

vii) Number of rainy days per annum 120 viii) Basic wind pressure 200 kgf/mm2

ix) Altitude Not exceeding 1000 m.

x) Minimum ambient air temperature 0 °C

4.2 The Potential Transformer would also be subjected to vibrations on account of trains

running on nearby railway tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 to 70 milli-second lies in the range of 30 to 150 microns at present, with the instantaneous peak going upto 350 microns.

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These vibrations may become more severe as the speeds and loads of trains increase in future.

5. TRACTION POWER SUPPLY SYSTEM

5.1 General Scheme 5.1.1 The single phase 50 Hz power supply for railway traction system at 25 kV is obtained

from 220/132/110/66 kV three phase grid system through a step down, single phase power transformer, the primary winding of which is connected to two of the phases, the three phase effectively earthed transmission line network of the State Electricity Board or Railways. The primary voltage of the Traction transformer being 220 kV or 132 kV or 110 kV or 66 kV and no load secondary voltage being 27.5 kV (Nominal secondary voltage is 25 kV). In order to reduce the imbalance on the three-phase transmission line are tapped in a cyclic order for feeding the successive traction sub stations (TSS). The distance between adjacent TSS is normally between 50 km to 80 km depending upon density of traffic, gradient in the section and other factors.

5.1.2 One terminal of the 25 kV secondary winding of the traction transformer is connected

to the OHE through circuit breakers / interrupters and the other terminal is solidly earthed and connected to the appropriate traction rail(s). The current flows through the OHE, to the locomotives and returns through the rail(s) and earth to the TSS. The sections where booster transformers and return conductor are provided the current returns through these; the traction rail(s) and partly through the earth in the vicinity of TSS. Approximately midway between two adjacent TSS a dead zone known as ‘neutral section’ or ‘phase break’ is provided to separate the two sections of OHE by different phases. The power fed to the OHE on one side of the TSS is controlled by a feeder circuit breaker while the power fed to the OHE of each track is controlled by an interrupter. In the case of a fault on the OHE, the feeder circuit breaker trips isolate the faulty OHE. A schematic diagram No. ETI.PSI/702 – 1 showing general arrangement at a TSS is at Annexure 1.

5.1.3 Normally power supply from a TSS extends upto the SP on either side of the TSS, but

in case of an emergency necessitating total shut down of the substation, power supply from the adjacent TSS on either side of the failed substation can be extended upto the failed substation by closing the bridging interrupters at the two Sectioning & Paralleling post (SPs).

5.2 Nature of Load on the 25 kV System

The traction load is of frequent and rapidly varying nature and fluctuates between no load and overloads. The load cycle varies from day to day due to non-uniform pattern of traffic.

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5.3 Electrical Parameters 5.3.1 The OHE is made up of a stranded cadmium copper catenary of 65 mm2 cross section

or a stranded aluminum alloy catenary of 116 mm2 cross section and a grooved contact wire of 107 mm2 or 150 mm2 cross section, making up a total of 150 mm2 or 210mm2 copper equivalent. The OHE impedance values are generally taken as under:

(i)

Single track OHE without return conductor

0.41 ∠ 70° Ohm/km

(ii)

Double track OHE without return conductor

0.24 ∠ 70° Ohm/km

(iii)

Single track OHE with return conductor

0.70 ∠ 70° Ohm/km

(iv)

Double track OHE with return conductor

0.43 ∠ 70° Ohm/km

(v)

Add booster transformer impedance where these are provided

@ 0.15 Ohms per booster transformer.

(vi)

Percentage impedance of traction transformer at 27 kV.

(12 +/- 0.5)% (21.6 MVA base)

5.4 Scheme of Protection.

5.4.1 The scheme of protection to be provided at each of the TSS shall comprise of the following :

a) Protection of the 220/27 kV or 132/27 kV or 110/27 kV or 66/27 kV traction

transformer installed at TSS. b) Protection of the 25 kV overhead equipment.

5.4.2 The following relays / instrument shall be fed by the potential transformer of 52 kV

class metering and indicating protection of transformer and feeder:

(i) Relays / instruments fed by protection type PTs. a) Admittance (Mho) relay for distant protection b) Admittance (Mho) relay for wrong phase coupling. c) Voltmeter at control relay panel at TSS to indicate 220kV or 132kV or

110 kV or 66 kV or 25 kV bus voltage. d) Transducer for telemetry of voltage.

(ii) Relays / instruments fed by line indication type PTs a) Catenary indication relay. b) Transducer for telemetry of line voltage

(iii) Supply to metering.

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6. RATING AND GENERAL DATA

6.1 The potential transformer shall be designed for the following rating and other particulars:

(i) Type : Core type, single phase, outdoor

installation, oil immersed, self-cooled suitable for mounting on structural steel supports.

(ii) System voltage :

a) Nominal system : 220 132 110 66 25 voltage kV (rms) b) Highest system : 245 145 123 72.5 52 voltage kV (rms)

(iii) Rated frequency : 50 Hz. ± 3%.

(iv) (i) Rated primary voltage kV (rms) : 220/3 or 132/ 3 or 110/ 3 or 66/ 3

For 25 kV : (a) 27.5 kV – Where the no-load voltage

of OHE and SCADA system are calibrated at 27.5 kV.

(b) 25 kV – Where the existing OHE voltage having SCADA and the relevant meters for indication / protection calibrated at 25 kV.

(ii) Rated secondary voltage, V : 110/ 3 for 220kV or 132kV or 110kV or 66kV

For 25 kV : (a) 100 V (type I for line indication) (b) 110 V (type II for protection ).

(v) Rated burden at 0.8 power factor (VA) :

(a) For 220 kV or 132kV or 110kV or 66kV 30 VA

(b) 25 kV (i) 30 VA (For type I) (ii) 100 VA (For type II)

(vi) Class of insulation A

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(vii) Rated voltage factor 1.2 for 30 sec.

(viii) Rated Insulation level

a) Highest system : 245 145 123 72.5 52 voltage kV (rms) b) Rated power frequency : 395 275 230 140 95 withstand voltage kV (rms) c) Lightning impulse : 950 650 550 320 250 withstand voltage kV (peak)

(ix) Temperature rise limits The temperature rise over an ambient of

(temperature measured by 50ºC shall not exceed the value indicated resistance method) below:

(a) Winding : 45 ºC. (b) Oil : 35 ºC.

(c) Current carrying parts in air : 40 ºC.

(x) Bushings (Porcelain Housing) :

i) Type Single piece construction and free from

ribs on the under side ii) Highest voltage for equipment, kV rms 245 145 123 72.5 52 iii) Minimum creepage distance in air, mm 6125 3625 3075 1813 1300

6.2 Accuracy Class

The potential transformers of 220kV or 132kV or 110 kV or 66 kV shall have the following accuracy as per clause of IS : 3156-1992. (i) For the burden varying between 25% and 100% of the rated burden and with

the applied primary voltage varying from 90% to 110% of the rated voltage, the ratio error shall not exceed +/- 1% and the phase angle error +/- 30 minutes.

(ii) With the applied primary voltage varying between 5% and 120% of the rated

voltage and with burden 25% to 100% of the rated burden at a power factor of 0.8 lagging, the ratio error shall not exceed +/- 3% and the phase angle error +/- 120 minutes.

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The potential transformers of 25kV (Type-I & Type-II) shall have the following accuracy as follows : (i) For type – I, potential transformer (line indication) shall conform to accuracy

class 6P of IS 3156 (Part III)-1992. Relevant details are indicated below :

At rated frequency, for any voltage between 5% and 120% of the rated voltage and with burdens between 25% and 100% of the rated burden at a power factor of 0.8 lagging the voltage error and phase displacement shall not exceed +/- 6% and +/- 240 minutes respectively.

(iii) For type – II, potential transformers (protection) shall conform to accuracy

class 1.0 of IS: 3156 (Part-II)-1992 and to accuracy class 3P of IS : 3156 (Part-III)-1992. Relevant details are indicated below :-

At rated frequency, for any voltage between 80% and 120% of rated voltage and with burdens 25% and 100% of rated burden at a power factor of 0.8 lagging, the voltage error and phase displacement shall not exceed +/- 1% and +/- 40 minutes respectively.

At rated frequency, for any voltage between 5% and 120% of the rated voltage and with burdens between 25% and 100% of the rated burden at a power factor of 0.8 lagging, the voltage error and phase displacement shall not exceed +/- 3% and +/- 120 minutes respectively.

7. CONSTRUCTIONAL FEATURES

7.1 The core shall be built up of high grade, cold rolled grain oriented, non-ageing steel

laminations conforming to IS : 3024-1996, the laminations shall be coated on both sides with suitable insulation, capable of withstanding short circuit forces.

7.2 One terminal of the primary winding shall be connected to the phase conductor of the

220kV / 132kV / 110kV / 66 kV / 25kV system and the other terminal brought out through a 3.6 kV class bushing and connected to the tank externally by means of a suitable tin coated copper link. The tank shall be provided with two terminals suitable for taking double earth connections by means of 50 mm x 6 mm MS flat.

Both the ends of the secondary winding shall be brought out and terminated on

suitable insulated terminals which shall be fully protected by a weather-proof terminal box designed to accommodate cartridge fuses as mentioned in Clause 7.6 below and fitted with a cable gland suitable for 2.5 sq.mm PVC insulated and PVC sheathed 1.1 kV grade conforming to IS:1554 (Part I)-1998 Copper cable.

7.3 The connection between primary terminal and primary winding shall be by means of

flexible copper wire and shall be provided with crimped copper lugs, nuts and bolts for proper fixing. For better mechanical strength and reliability, it is preferable that

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primary winding lead connection with the terminal plate are provided at two / three places as shown in the sketch at Annexure – 5.

7.4 The potential transformer shall be of sealed construction with inert gas (Nitrogen)

above the insulating oil, and adequately protected against any leakage of gas or oil. A pressure release device capable of releasing abnormal internal pressure shall however, be provided. The number of gasketted joints shall be restricted to the minimum

7.5 Class ‘A’ insulation, immersed in insulating oil shall be used. The transformer shall

be supplied complete with insulating oil conforming to IS:335-1993 and ready for commissioning. The characteristics of insulating oil before energizing the new potential transformer shall conform to the parameters as stipulated in IS: 1866-1991.

7.6 Cartridge type fuse links conforming to BS:9224 (Part-II)-1993 shall be provided in

the weather proof terminal box for the secondary circuit with continuous current rating of 4A except for 25 kV PT (Type – I) of 2A.

7.7 The tank shall be of welded mild steel construction designed to withstand internal

stresses due to short circuits. All cover seats, flanged joints, threaded connections and pipe fittings shall be properly machined, fitted and gasket to ensure oil tightness. The construction of the tank shall be such as to shed off any rain water.

7.8 A port shall be provided on the oil expansion chamber to serve the purpose of oil

filling and also for fixing the nitrogen gas filling assembly. The nitrogen gas filling assembly shall be screwed into the oil filling port and shall have its own leak-proof sealing. A screwed cap shall be provided on the oil filling port with gasket or ‘O’ ring provided at suitable location. The internal and external threads provided on the oil filling port shall be of an adequate length and shall conform to the “precision grade” as defined in IS: 1367-1996.

7.9 The oil draining pipe provided on the bottom tank shall have suitable internal threads

over an adequate length and a threaded plug should be screwed into this pipe. The assembly of the threaded pipe and plug shall conform to the “precision grade” as defined in IS: 1367-1996. In addition, a gasket or ‘O’ ring shall be provided at suitable location in the assembly.

7.10 All the bolted mechanical and electrical connections in the transformer shall be

positively prevented from loosening in the service due to vibration. Standard locking arrangements shall be employed for this purpose.

7.11 The electrical joints (if any) within the transformer winding shall be minimum, and

shall be brazed. 7.12 The transformer assembly shall be dried under vacuum till appropriate values of

insulation resistance have been obtained. It shall then be impregnated under vacuum with transformer oil conforming to IS:335-1993.

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7.13 No Grading ring shall be used in the construction of the 25 kV PT. 8. PORCELAIN HOUSING AND TERMINAL CONNECTORS 8.1 The porcelain housing shall be of single piece construction i.e. there shall be no joint

in the porcelain body. The shed profile shall have a lip at the extremities but free from ribs on the underside.

8.2 The design and construction of the porcelain housing shall be such that stresses due to

expansion and contraction in any part there of shall not lead to its deterioration / breakage.

8.3 The porcelain housing shall conform to IS:5621-1988 and shall withstand the

ollowing test voltages:-

a) Highest system voltage for : 245 145 123 72.5 52 equipment, kV (rms)

b) Rated short duration wet/dry: 460 275 230 140 95 power frequency withstand voltage kV (rms)

c) Rated lightning impulse: 1050 650 550 320 250 withstand voltage kV (peak)

8.4 The primary terminal of potential transformer shall preferably be of stainless steel and

suitable for vertical take off for fixing a rigid type terminal connector. This terminal plate shall be carefully welded at the location where it passes through the top plate of the expansion chamber. The joint between the terminal plate and the oil expansion chamber shall have adequate mechanical strength and shall be proof against leakage of nitrogen gas and ingress of moisture.

8.5 The terminal connector shall be as per Research Designs and Standard Organization

(RDSO), drawing No. ETI/PSI/P/11120 and shall conform to IS:5561-1992. The terminal connector drawing is placed at Annexure-2. Terminal connectors shall be procured only from RDSO’s approved manufacturers.

9. FASTENERS

9.1 All fasteners of 12 mm diameter and less, exposed to atmosphere shall be of stainless

steel and those above 12 mm diameter shall preferably be of stainless steel or of mild steel hot dip galvanized. The material of the stainless steel fasteners shall conform to IS: 1570 (Part V)-1991 Grade 04, Cr 17 Ni 12 MO 2.

10. PAINTING (i) All steel surfaces in contact with insulating oil shall be properly treated and

then painted with heat resistant, oil insoluble insulating varnish.

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(ii) All steel surfaces exposed to atmosphere shall be properly treated and then

painted with one primer coat of zinc chromate and two coats of enamel gray paint to shade 631 of IS: 5-1994.

11. RATING PLATE 11.1 The potential transformer shall be provided with a rating plate (both in Hindi and

English) of weather proof material, fitted in a visible position, showing the items indicated below. The lettering / numbering on the plate shall be indelibly marked by etching / engraving.

(i) Type designation of potential transformer (ii) Governing specification (iii) Manufacturer’s name and country of origin (iv) Manufacturer’s serial number (v) Year of manufacture (vi) Rated voltage factor and corresponding rated time (vii) Rated frequency (viii) Highest voltage for equipment (ix) Rated voltage

(a) Primary (b) Secondary

(x) Rated output and corresponding Accuracy class (xi) Maximum temperature rise over an ambient of 50 Deg. C

(a) of oil (b) of winding

(xii) Rated Insulation levels (xiii) Total weight (xiv) Connection diagram.

12. PARTS, FITTINGS AND ACCESSORIES

The following accessories shall be provided with each potential transformer : (i) Rating and diagram plate (ii) Terminal marking plate (iii) Weather proof terminal box (iv) Lifting lugs (v) Cable gland to take cable 2.5 mm2 / 1100 V grade PVC insulated / PVC

sheathed (Heavy Duty) Copper cables. (vi) Oil filling port and nitrogen gas filling valve (vii) Oil drain pipe with plug (viii) Two equipment earthing terminals (ix) Pressure relief device (x) Terminal connector

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(xi) Oil level sight gauge (tough acrylic plastic) (xii) Plain rollers (xiii) Adjustable arcing horn.

13. DRAWINGS 13.1 The successful tenderer shall submit the following detailed dimensioned drawings

along with three prints of each as per Railway Standards in sizes of 210 mm x 297 mm or any integral multiple thereof for scrutiny / approval. A format to title sheet to be adopted for preparation of these drawings is attached at Annexure- 3.

(i) Outline general arrangement showing overall dimensions of the PT, position

of terminals and base mounting channels. (ii) Cross sectional view showing core, winding, expansion chamber and

connection of primary side terminal to primary winding. (iii) Detailed drawing of porcelain housing indicating shed profile, creepage

distance and salient electrical and mechanical technical parameters. (iv) Clamping arrangement for porcelain housing. (v) Details of Pressure relief device (vi) Details of Oil filling port and Nitrogen gas filling valve (vii) Details of Secondary terminal assembly (viii) Details of Secondary terminal box (ix) Details of Primary terminal plate (x) Details of Oil drain plug arrangement (xi) Details of cable gland, ‘O’ ring and gaskets used. (xii) Details of oil level indicator (xiii) Rating and diagram plate (English and Hindi version). (xiv) Insulation details for active part. (xv) Arrangement of earthing terminal

13.2 The provisionally approved drawings shall be modified, if need be, as a result of

changes necessitated during type testing or as desired by the Purchaser. The modification shall be first got approved from the Purchaser / Director General (Traction Installation) Research Designs and Standards Organisation, [DG(TI)RDSO], Lucknow and then incorporated in the drawing and each such modification shall be got signed by the authority concerned on the drawings. If there are no modifications at all the provisionally approved drawings shall be finally approved.

13.3 Six copies of approved drawings alongwith two sets of reproducibles shall be sent to

each consignee(s), as indicated in the purchase order. Besides two copies of drawings alongwith one set of reproducible tracings shall be supplied to CEE/CORE/ALD and one set of drawing to DG / TI / RDSO, Lucknow.

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13.4 The successful tenderer shall also be required to supply at least two copies of the “Inspection and Maintenance Manual” for potential transformer to each consignee, CEE/CORE/ALD and two copies to DG (TI) RDSO, Lucknow – 226 011.

14. TESTING OF TRANSFORMER 14.1 General 14.1.1 Once a purchase order is placed for supply of a potential transformer (PT) the designs

and drawings shall be furnished to the Purchaser/DG (TI), RDSO, Lucknow as the case may be within the period stipulated in the purchase order. Only after all the designs and drawings as well as quality assurance plan (QAP) have been approved for prototype tests and written advice given to that effect, successful tenderer / manufacturer shall take up manufacture of the prototype of the potential transformer. It is to be clearly understood that any change or modification required by the above authorities to be done in the prototype shall be done expeditiously, not withstanding approval having already been given for the designs and drawings. Such change or modification shall be incorporated in the drawing as indicated in Clause 13.0.

14.1.2 Prior to giving a call to the Purchaser/DG (TI), RDSO, Lucknow, for inspection and

testing of the prototype, the successful tenderer / manufacturer shall submit a detailed test schedule containing procedures and schematic circuit diagrams for each of the tests and the number of days required to complete all the tests at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the purchaser reserves the right to conduct any additional test(s), besides those specified herein, on any equipment / item so as to test the equipment / item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and representative of the Purchaser / DG(TI), RDSO, Lucknow, during the process of testing as regards the procedure for type tests and/or the interpretation and acceptability of the results of type tests, it shall be brought to the notice of the Purchaser / DG(TI), RDSO, Lucknow, as the case may be, whose decision shall be final and binding. Only after the prototype transformer is completed and ready in each and every respect, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with at least 15 days notice for the purpose.

14.1.3 In the event of the test not being completed at one stretch for any reason attributable

to the successful tenderer / manufacturer and it is required for the representative of the Purchaser / Director General (Traction Installation), Research Designs & Standards Organisation DG (TI) RDSO, Lucknow to go again or more number of times to the works of the successful tenderer / manufacturer or other place(s) for continuing and / or completing the tests on the prototype(s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser / DG (TI) RDSO, Lucknow, the costs for the representative having to visit to the works or other place(s) for the tests more than once. The cost as claimed by the Purchaser / DG (TI), RDSO,

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Lucknow, shall be paid through a demand draft to the concerned accounts officer of the Purchaser / DG (TI), RDSO, Lucknow, as shall be advised to the successful tenderer / manufacturer. However, it shall be reviewed by Purchaser / DG (TI), RDSO, Lucknow, based upon the factual conditions / circumstances at the time of conducting tests.

14.1.4 The type tests shall be carried out on the prototype transformer at the works of the

successful tenderer / manufacturer or at a reputed testing laboratory in the presence of the representative of the Purchaser / DG (TI), RDSO, Lucknow, in accordance with the relevant specifications and as modified or amplified by this specification.

14.2 Type Tests 14.2.1 The type tests shall be carried out on the prototype PT at the works of the successful

tenderer / manufacturer or at any reputed laboratory in the presence of the representative of the Purchaser / DG (TI) RDSO, Lucknow, and in accordance with the relevant specifications and as altered, amended or supplemented by this specification.

(i) Temperature rise test. (ii) Lightening Impulse test (iii) Chopped Lightening Impulse test (iv) High voltage wet power frequency withstand test (v) Determination of errors (vi) Short Circuit withstand capability test.

14.2.1.1 Temperature Rise Test

This test shall be done in accordance with clause 9.5 of IS: 3156 (Part-I)-1992. The maximum temperature rise of the PT after continuous operation shall not exceed the following values over an ambient temperature of 500 C.

(i) For windings 450 C (by resistance method)

(ii) For insulating oil 350 C (by thermometer).

14.2.1.2 Lightning Impulse Test

The test shall be done in accordance with Clause 9. 6 of IS: 3156 (Part-I)-1992. The PTs shall withstand an impulse t est voltage of :

i) Highest voltage for equipment kV (rms) 245 145 123 72.5 52 ii) Lightning impulse withstand 950 650 550 320 250

voltage, kV (peak).

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14.2.1.3 Chopped Lightning Impulse Test This test shall be carried out on primary winding in accordance with Clause 9.8 of IS: 3156 (Part-I)-1992 and the test voltage are same as under clause 14.2.1.2.

14.2.1.4 High Voltage Wet Power Frequency Withstand Test

The test shall be conducted in accordance with Clau se 9.7 of IS: 3156 (Part-I)-1992. The test voltage shall be appli ed as under :

i) Highest voltage for equipment kV (rms) 245 145 123 72.5 52 ii) Rated power frequency withstand 395 275 230 140 95

voltage (wet), kV (rms). 14.2.1.5 Determination of Errors

Determination of errors shall be carried out in accordance with IS: 3156 (Part-II)-1992 & IS: 3156 (Part-III)-1992 in conformity with clause 6.2 of this specification.

14.2.1.6 Short Circuit Withstand Capability Test

The test shall be conducted in accordance with Clause 9.9 of IS: 3156 (Part-I)-1992.

14.3 Type Test on Accessories 14.3.1 Porcelain Housing

The porcelain housing shall be tested in accordance with IS: 5621-1988 and shall also meet the requirements of clause 8 of this specification.

14.3.1.1 Terminal Connectors

The terminal connectors shall be tested in accordance with IS: 5561-1992. 14.3.1.2 Pressure Relief Device

The pressure relief device shall be subjected to air pressure test and leakage test. The pressure relief device should operate at a pressure between 2.5 to 4.5 kg/cm2.

14.3.2 Insulating Oil

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The sample of insulating oil drawn from the prototype unit shall be tested in accordance with IS: 335-1993.

14.4 Routine Tests 14.4.1 The following routine tests shall be performed on each PT including prototype in in

accordance with IS: 3156 –1992. (i) Visual Examination (ii) Verification of polarity of terminal markings. (iii) Measurement of winding resistance (iv) Measurement of insulation resistance (v) Power frequency dry withstand test on primary winding (vi) Power frequency dry withstand test on secondary winding (vii) Determination of errors (viii) Partial discharge measurement (Applicable for nominal system voltage above

66 kV). 14.4.1.1 Visual examination

A general examination shall be made to check that the potential transformer conforms to the approved drawing, various items are accessible for maintenance, the quality of workmanship and finish are of acceptable standards and all parts, fittings and accessories are provided.

14.4.1.2 Verification of terminal marking and polarity

Terminal markings and polarity shall be verified as per clause 9.2 of IS:3156 (Part – I)-1992.

14.4.1.3 Measurement of winding resistance

The resistance of primary and secondary windings shall be measured and computed at 75°C.

14.4.1.4 Measurement of insulation resistance The insulation resistance between primary and secondary windings and between secondary winding and earth shall be measured with 500 V megger.

14.4.1.5 Power Frequency Dry Withstand Test on Primary Winding This test shall be done in accordance with clause 9.3 of IS:3156 (Part – I)-1992. The test voltage shall be applied as under :

i) Highest voltage for equipment, kV (rms) 245 145 123 72.5

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52 ii) Rated short duration power frequency 395 275 230 140 95 withstand voltage, kV (rms).

The induced over voltage withstand test shall be done in accordance with clause 9.3.2.2 of IS:3156 (Part – I)-1992. As one end of the primary winding is solidly earthed in these PTs, separate source withstand voltage test can’t be conducted.

14.4.1.6 Power Frequency Dry Withstand Test on Secondary Winding

This test shall be conducted in accordance with clause 9.4 of IS:3156 (Part – I)-1992. The test voltage applied shall be 3 kV rms for one minute between secondary winding terminals and earth.

14.4.1.7 Determination of Errors (Accuracy Class) Determination of errors shall be carried out in accordance with IS:3156 (Part – II and III)-1992 and it shall meet the requirement indicated in clause 6.2 of this specification.

14.4.1.8 Partial Discharge Measurement

This test shall be conducted in accordance with IS : 11322 – 1990. 14.5 In the event of the potential transformer failing in any one of the tests, further tests

will not be carried out by the representative of the Purchaser/ DG/TI/RDSO. The manufacturer; after carrying out the necessary rectification / modifications as required on the potential transformer with the further approval from the Purchaser / DG(TI) RDSO, offer a fresh prototype for carrying out all the tests stipulated above.

15 TECHNICAL DATA AND DRAWINGS. 15.1 The tenderer shall furnish alongwith his offer, in the proforma at Annexure – 4, the

Schedule of Guaranteed Performance and Other Particulars (SOGP) for the potential transformer. The particulars shall be correct and complete in all respects. If there is any entry like “shall be furnished later” or a blank against any item, the offer is not likely to be considered as the evaluation of the offer is rendered difficult and cannot be compared with other offers, if any.

15.2 The tenderer shall specifically indicate in a “Statement of Compliance” attached with

the offer, his compliance with each and every clause of this specification. In case the tenderer wishes to deviate from any clause of this specification he may do so giving reference to the clause(s) with the reasons/justification for the deviation. This shall be in the form of a separate statement called the “Statement of Deviations”. If there is no deviation at all, a specific “NIL” “Statement of Deviations” shall be attached with the offer. If the “Statement of Compliance” and “Statement of Deviation” are not

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attached with the offer, it is not likely to be considered for the reason that it is an incomplete offer which cannot be properly evaluated and compared with other offers, if any.

15.3 The tenderer shall furnish the following drawings, alongwith the offer :

(i) Outline general arrangement drawing giving the overall dimensions of the potential transformer along with a cross sectional view.

(ii) Rating and diagram plate. (iii) Internal arrangement of the PT including cross-sectional views.

16. SPARES

Wherever required, the tenderer shall quote apart from main equipment, separately for recommended spares required for five years operation The tenderer shall also quote separately for the following essential spares. (i) Primary porcelain housing (ii) Primary terminal connector

17. TRANSPORTATION OF THE POTENTIAL TRANSFOR MER 17.1 The potential transformer may be transported according to the transport facilities

available for the route, viz. by rail, road or sea. All parts, fittings and accessories which are liable to damage during transit shall be removed and packed / crated separately. Detached parts may be packed / crated and sent with potential transformer along with the check list, so that all the parts are available at the destination with the unit. The packing has to be done properly so that no damage occurs during transit.

17.2 The various components of each potential transformer shall be securely packed in

wooden crates / boxes. General packing list, together with weight and overall dimensions of packing cases shall be furnished for each transformer indicating the following particulars : -------------------------------------------------------------------------------------------------- Crate No. Description of Item / Approx. gross Approx. outside component in the crate weight in Kg. Dimensions

17.3 As far as possible, the gross weight of the crate / box shall be so kept that it can be conveniently handled by two persons.

17.4 In case of overseas supplies, packing shall be sea-worthy. 17.5 Necessary instructions for handling and storage of all items shall be included along with the packing lists. 18. AFTER SALES SERVICE

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18.1 The successful tenderer shall make necessary arrangements for closely monitoring the performance of the potential transformers through periodical (preferably once in two months during the warranty period) visits to the location where they have been erected for observations and interaction with the operating and maintenance personnel of the Indian Railways. Arrangements shall also be made by the successful tenderer for emergency / standby spare parts being kept readily available to meet exigencies warranting replacement so as to keep the transformer in service with least down time.

18.2 The successful tenderer shall respond promptly and in workman like manner to any

call given by Indian Railways for any assistance by way of attending to failures, investigation into the causes of failures including tests, if any, to be done and such other items with a view to seeing that the potential transformer serves the purpose for which it is intended. Besides technical guidance to ensure proper operation and maintenance of the potential transformer shall be constantly rendered.

19. WARRANTY 19.1 The successful tenderer/manufacturer shall warrant that all equipment shall be free

from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally accepted standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

19.2 This warranty shall cover inspection of, payment for and acceptance of the equipment,

but shall expire 24 (Twenty Four) months after the delivery at ultimate destination, or 18 (Eighteen) months from the date of commissioning and proving test of the equipment at ultimate destination in India, whichever period expires earlier, except in respect of complaints, defects and/or claims notified to the successful tenderer / manufacturer within 3 (Three) months of the expiry of such date. Any approval or acceptance by the Purchase of the equipment shall not in any way limit the successful tenderer/manufacturer’s liability.

19.3 The successful tenderer/manufacturer’s liability in respect of any complaint, defects

and/or claims shall not be limited to the furnishing and installation of replacement of parts free of any charge or the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer/manufacturer within 3 (Three) months of their being first discovered during the warranty period of 3 (Three) months form the date of expiry of warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned.

19.4 The successful tenderer/manufacturer shall, if required, replace or repair the

equipment of such portion thereof as is rejected by the Purchaser free of cost at the ultimate destination or at the option of the Purchaser, successful tenderer/manufacturer shall pay to the Purchaser value thereof at the contract price or in the absence of such price at a price decided by the Purchaser and such other

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expenditure and damages as may arise by reason of the breach of the conditions herein specified.

19.5 All replacement and repairs that the Purchaser shall call upon the successful

tenderer/manufacturer to deliver or perform under this warranty shall be delivered and performed by the successful tenderer/manufacturer, promptly and satisfactorily and in any case within 2 (Two) months of the date of advice to this effect.

19.6 If the successful tenderer/manufacturer so desires, the parts that are removed may be

taken over by him or his representative for disposal as he deems fit at the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.

19.7 The warranty herein contained shall not apply to any material which shall have been

repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer/manufacturer, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

19.8 The decision of the Purchaser in regard to successful tenderer/manufacturer’s liability

and the amount, if any, payable under this warranty shall be final and conclusive.

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____________________________________________________________________

SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS . --------------------------------------------------------------------------------------------------------------- S. No. Description Unit of Value / formation

Measurement 220kV/132kV/ 110kV/66kV/25kV. (type I & II)

--------------------------------------------------------------------------------------------------------------- 1. Name of the manufacturer 2. Country of origin 3. Standard governing specification 4. Manufacturer’s Type designation 5. Rated (System) voltage

(a) Highest system voltage for equipment kV rms. (b) Rated primary winding voltage kV rms. (c) Rated secondary winding voltage kV rms

6. Rated frequency Hz. 7. Insulation resistance between secondary Mohm

Winding & earth and between primary & secondary winding.

8. Rated burden VA 9. Rated voltages and transformation ratio 10. Class of accuracy.

Ratio error (%) and phase angle error (minute) (a) for voltage varying from 90% to 110%

or 80% to 120% of rated voltage. (b) for voltage varying from 05% to 120%

of rated voltage.

11. Rated voltage factor

12. Maximum temperature rise after continuous

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full load operation of: (a) oil by thermometer °C (b) winding by resistance °C

13. Winding particulars

(a) Type of primary winding (b) Current density in primary winding A/mm2 (c) Size and no. of turns of conductors

for primary / secondary winding (d) Class of insulation (e) Rated insulation level

(i) Impulse withstand voltage kV peak. (ii) Power frequency induced

withstand voltage kV rms. (f) Resistance of primary winding at 75°C Ohms (g) Resistance of secondary winding at 75°C Ohms.

14. Core particulars

(a) Type of core (b) Flux density at rated voltage and frequency Tesla (c) Thickness of steel laminations mm (d) Whether CRGO steel stamping used? yes/no.

15. Porcelain housing / bushing particulars.

(a) Name of manufacturer (b) Standard Governing Specification (c) One minute dry power frequency withstand kV rms. (d) One minute wet power frequency withstand kV rms. (e) Lightning impulse withstand kV peak. (f) Under oil flashover or puncture withstand,

Power frequency voltage kV rms. (g) Under oil flashover or puncture withstand,

Impulse voltage kV peak. (h) Creepage distance in air mm (i) Weight of bushing / porcelain housing kg

16. LT. Fuse Particulars :

(a) Make & Type (cartridge & rewirable) (b) Continuous current rating A (c) Fusing current A (d) Governing specification

17. Weights and dimensions :

(t) Net weight of core kg

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(u) Net weight of copper kg (v) Net weight of Primary winding kg (w) Net weight of Secondary winding kg (x) Quantity of insulating oil (volume) l (y) Weight of insulating oil kg (z) Total weight of potential transformer with oil kg (aa) Overall dimensions of the assembled transformer

(i) Height (topmost) mm (ii) Length mm (iii) Breadth mm 18. Whether the PT is of sealed construction with

inert gas at top ? Yes / No

19. Whether terminal connectors will be provided? Yes / No 20. Are the exposed fasteners of 12 mm dia or less of stainless steel? Yes / No 21. Are the exposed fasteners of more than 12 mm dia. exposed to

atmosphere are of stainless steel or of MS hot dip galvanized? ---- 22. Is the porcelain housing of single piece construction? Yes / No 23. Is the shed profile of porcelain housing free from under ribs,

but has a lip? Yes / No 24. Pressure release device are provided or not? Yes / No 25. Whether deviation statement submitted? Yes / No 26. Is the warranty as per clause 19.0? Yes / No 27. Is the list of spares furnished? Yes / No 28. Are all the drawings required as per Clause - 15.3 attached? Yes / No

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LIST OF ABBREVIATIONS

ABBREVIATIONS FULL FORM OF THE ABBREVIATION

OHE

Over Head Equipment

PT Potential Transformer

TSS Traction Sub Station

SP Sectioning and Paralleling Post (Switching Station)

QAP Quality Assurance Plan

DG (TI) Director General (Traction Installation)

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RDSO Specification No.TI/SPC/PSI/PTS/0990 for Potential Transformers The following amendments are made in addition to the addendum and corrigendum slips issued to this specification. S.No. Clause No. Amendment In the title of the specification add “or 22 kV ‘after “25 kiV”. 1. Clause 1.1 Add in 2nd line, “or 22 kV” aftaer 25 kV (Type-I & II) 2. Clause 1.3 Deleted. 3. Clause 1.4 Deleted 4. Clause 2.1 In 3rd line, substitute 50ºC with 45ºC and in 4th line, substitute 40ºC with 35ºC 5. Clause 4.1 I) Change 50ºC to 45ºC ii) Change 40ºC to 35ºC vii) Change 200 Kgf/m2 to 112.5 Kgf/ m2

x) Change 0ºC to 5ºC 6. Clause 5.1.1 In line No.9, substitute 50 km to 80 km with “6.5.km to 25 km” 7. Clause 5.1.2 In line 11, substitute the word “interrupter” wotj “circuit breaker” 8. Clause 5.3.1 Add at the end. However the confifguratiion of OHE at the particular TSS is 242 sq.mm. catenary and 193 sqmm contact wire. 9. Clause 5.4.2 (i) (a) Substitute the words “Admittance (Mho) relay for distance protection” with “Directional parallelogram characteristics time graded distance relay” 10. Clause 6.1 Add another column to the table at the right hand side and read the following (ii) (a) 22 (b) 24

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(iv) (i) or 22/3 kV (ii) or 22/3 V (v) (a) Add “or 22 kV” after the word “66kV” Add another column to the table at the right hand side and read the following. (viii) (a) 24 kV (b) 50 (c) 125 (ix) Change 50ºC in line 1 to 45ºC (x) Add another column to the table at the right hand side

and read the following. (ii) 22kV (iii) 1300mm 11. Clause 6.2 Add in line 1 after 66kV “or 22kV” 12. Clause 7.2 In line 2 add “/22 kV” after 25kV 13. Clause 8.3 Add another column to the table at the right hand side and read the following. a) 24 b) 50 c) 125 14. Clause 13.2 Deleted 15. Clause 13.3 Delete the sentence staring the “Besides two

copies:…….upto………….”Lucknow”. 16. Clause 13.4 Delete 3rd line. 17. Clause 14.1.1 In line 4 & 5, delete words staring with “for prototype

tests”…….till…….”to that effect”.

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18. Clause 14..1.2& Delete 14.1.3 19. Clause 14.1.4 In line 1 delete the word ”prototype”. 20. Clause 14.2.1 In line 1 delete the word ”prototype”. 21. Clause 14.2.1.1 In line substitute 50ºC with 45ºC. 22. Clause 14.2.1.2 Add another column to the table at the right hand side

and read the following. (i) 24 (ii) 125 23. Clause 14.2.1.4 Add another column to the table at the right hand side

and read the following. (i) 24 (ii) 50 24. Clause 14.4.1 In line 1, delete the works”including prototype” before

the works “in accordance”. 25. Clause 14.4.1.5 Add another column to the table at the right hand side

and read the following. (i) 24 (ii) 50 26. Clause 14.5 Delete 27. Clause 16.0 Delete line 3,4 & 5 28. Clause 19.2 Change the existing clause as follows “The warranty

shall expire 36 (Thirty six) months after the delivery of equipment at the ultimate detination or 24 (twenty four) months from date of commissioning of the equipment whichever period occurs first.”

29. Clause 19.3 In line 8 delete the wors from “or” onwards till end. 30. In annexure 4, in the heading of the column 4 add / 22kV after 25kV (Type-I & II)

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Addendum/Corrigendum Slip No.2 (May 2003) to the specification No.TI/SPC/PSI/PTs/0990 for Potential transformer on 110 kV side of 30 MVA transformer at railway traction sub-stations which may be operated in parallel on the 25 kV side.

S.No. Clause No./

Page No. Description As amended

1 6.1 (4)-ii Page 9 Rated secondary voltage Read 110 V in place of 110/√3 V

( B.P. Singh ) For Director General/TI

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Addendum/Corrigendum Slip No.3 (August 2005) to the specification No.TI/SPC/PSI/PTs/0990 for Potential transformer on 110 kV side of 30 MVA transformer at railway traction sub-stations which may be operated in parallel on the 25 kV side.

S.No. Clause No./ Page No.


1. Annexure-7 Details of 110 kV potential transformers to be used in Mumbai area. This is to be read along with details given in the subject specifications.

New Annexure-7 added.

( B.P. Singh ) Director/TI-I

For Director General/TI

ANNEXURE-7

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1. SCOPE This part of specification cover design, manufacture, testing, inspection, packing and supply of 110 kV potential transformers to the specification given below to be used in Mumbai area at traction sub-station with 30 MVA transformers and required to be operated in parallel with adjacent traction sub-stations. 2.0 RATING AND OTHER PARTICULARS

1. Type Single phase, oil filled natural air cooled outdoor.

2. Nominal system voltage, kV 110 kV 3 Highest operating voltage 123 kV 4 Rated frequency 50 Hz +/- 3% 5 Neutral earthing Effectively grounded 6 Maximum temperature rise of

windings immersed in oil 45 °C over an ambient of 50°C

7 One minute 50 Hz withstand voltagae/induced over voltage

230 kV (rms)

8 Impulse withstand voltage, positive and negative polarity 1.2/50 microsecond wave.

550 kV peak

9 Minimum creepage distance of insulator (31mm/kV), mm

3813

10 P.T.Ratio 1) Rated primary voltage, kV (rms) 2) Rated secondary voltage V

100 kV -- 110 kV √3 √3 110 V & 110 V √3 √3

11 Application Metering on winding 1, Protection on winding 2.

12 Rated Burden 100 (Winding –1) 200 (Winding – 2)

13 Rated P.F. 0.8 14 Accuracy Class 0.2 for winding 1 and

3P for winding 2 15. Rated voltage factor 1.2 Continuous & 1.5 for 30 Sec. 16. The ratios corresponding to 110 kV 110 V - 110 V

√3 √3 √3 and 100 kV 110 V - 110 V √3 √3 √3 should be achieved by providing tap on lthe secondary windings.

17. The neutral terminal for the HT winding should be brought out through a bushing rated for 3.6 kV.

3.0 CONSTRUCTIION

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The Potential transformers shall be hermetically sealed. They shall be suitable for upright mounting on steel structures. They shall be provided with nitrogen cushions.

4.0 GENERAL 4.1 The Potential transformers shall be designed to withstand forces corresponding to a

seismic acceleration 0.1 g. 4.2 Potential transformers shall be provided with unthreaded stud/flat terminals made of

tinned copper at top for connections to consumer’s 110 kV bus comprising of IPS pipes.

4.3 The PT secondary shall be provided with disconnecting tupe links and necessary

fuses either in the secondary terminal box or in a separate junction box. 4.4 Design and construction of Potential transformers shall be sufficient to withstand the

thermal and mechanical stresses that they may be subjected to while in service. The core lamination shall be of high grade steel or other equivalent alloy. The exciting current shall be as low as possible and the Potential transformer shall be capable of maintaining its rated accuracy for burdens and saturation limits specified in Part one.

The secondary terminal shall be brought out in a weather-proof terminal box. The terminal box shall be provided with glads suitable for 2 Nos. 1100 V grade, steel wire armoured, PVC sheathed multicore, 2.5/4 sq.mm cables.

4.6 Polarity marks shall be indelibly marked on the primary terminals of the Potential

transformer and on the secondary lead terminations at the associated terminal block. For PT the secondary fuses shall be incorporated in the secondary terminal box.

4.7 Potential transformer shall be provided with nameplate showing particulars and

diagram of the connections. They shall be made of non-corrosive material, shall be indelibly marked and firmly fixed on to the body of Potential transformer.

4.8 The potential transformers shall be supplied complete with insulating oil conforming

to IS : 12463 and railway requirements. The insulating oil shall be procured from the manufacturers approved by RDSO. The successful tenderer/manufacturer shall submit test certificates as per IS:12463 for oil.

4.9 All ferrous parts exposed to atmosphere including main tank, secondary terminal box

& top metallic should be hot dip galvanized. 4.10 Equipment covered under this specification shall withstand seismic acceleration force

corresponding to 0.1 g.

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4.11 The tenderer shall furnish their compliance or otherwise against each clause/sub-clause of the technical specification. If the tenderer wishes to deviate from the provision of any clause/sub-clause, he shall furnish the full details with justification for such deviation.

4.12 Detailed drawings of PT alongwith SOGP shall be furnished for RDSO’s approval

before manufacture is taken up. 5.0 TESTS

The following Type & Routine tests as per RDSO specification No.TI/SPC/PSI/PTs/0990 with A&C slip No.1 & 2, IS: 3156 and relevant IEC shall be conducted on the potential transformer required for Mumbai area under DC-AC conversion.

5.1 Type tests. 5.1.1 Temperature rise test 5.1.2 Lightning impulse test 5.1.3 Chopped Lightning impulse test 5.1.4 Hiigh voltage wet power frequency withstand test 5.1.5 Determinatiion of errors 5.1.6 Short circuit withstand capability test 5.1.7 Determination of capacitance dissipation factor. 5.2 Routine tests. 5.2.1 Visual examination 5.2.2 Verification of polarity and terminal markings 5.2.3 Measurement of winding resistance 5.2.4 Measurement of insulation resistance 5.2.5 Power frequency dry withstand test on primary winding 5.2.6 Power frequency dry withstand test on secondary winding 5.2.7 Determination of errors 5.2.8 Partial discharge measurement 5.2.9 Oil leakage test.

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SPECIFICATION FOR

25kV DROP OUT FUSE SWITCH AND

OPERATING POLE

No. ETI / PSI / 14 (1 / 86)

191

SPECIFICATION NO. ETI/PSI/14 (1/86)

GOVERNMENT OF INDIA MINISTRY OF TRANSPORT


SPECIFICATION

FOR

25kV DROP OUT FUSE SWITCH AND

OPERATING POLE

ISSUED BY


MANAK NAGAR, LUCKNOW 226 011.

192


(DEPT. OF RAILWAYS) RESEARCH DESIGNS AND STANDARDS ORGANISATION

-------- Specification No. ETI/PSI/14(1/86)

25 kV DROP OUT FUSE SWITCH AND OPERATING POLE

1. SCOPE 5.1 This specification applies to outdoor, expulsion, drop out type fuse switches for

protection of 25 kV / 230 V, 10 KVA and 100 KVA LT supply transformers at the various traction installations.

5.2 The specification also covers insulated operating poles for opening / closing the fuse

link from ground level under live condition of the fuse switch. 5.3 The fuse switches and operating poles shall be complete with all parts and accessories

necessary for their efficient operation. All such parts and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not.

6.0 SERVICE CONDITIONS 6.1 The fuse switches are required to be used as isolating links-cum-fuses for protection

of the 25 kV / 230 V, 10 KVA and 100 KVA, 50 Hz single-phase LT supply transformers at traction substations, switching stations and way side railway stations. The transformer and fuse switch are mounted on the same mast, the line end or upper terminal of the fuse switch being connected to the substation switching station busbar or traction overhead equipment as the case may be, and the outgoing end or lower terminal, to the transformer.

6.2 Weather Conditions

The weather conditions under which the drop out fuse switch and operating pole are used vary widely. The limiting conditions which have to be withstood in service are indicated below : - Maximum temperature of air in shade 450C - Minimum temperature of air in shade 00C - Maximum temperature attainable by an 650 C object exposed to sun - Maximum relative humidity 100%

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- Average Annual rainfall 1750 to 6250 mm. - Number of thunder storm days / annum 85 days Max. - Average number of dust-storm days / annum 35 days Max - Number of rainy days / annum 120 days Max - Maximum wind pressure 200 kg/m2

- Altitude Not exceeding 1000 m.

6.3 In some area, the drop out fuse switch and operating pole are also subject to chemical

pollution from the effluent gases of chemical / fertiliser plants and to saline atmosphere on the lines near sea.

7.0 GOVERNING SPECIFICATION 7.1 The fuse switches shall, unless otherwise specified, conform to IS:9385(Part-II)-1980,

which shall be applied in the manner altered, amended or supplemented by this specification and the latest Indian Electricity Rules, wherever applicable.

7.2 The synthetic resin bonded glass fibre tube for operating pole shall conform to BS 8953-1976 (latest version).

7.3 Any deviation from this specification, calculated to improve the performance, utility and efficiency of the equipment proposed by the tenderer, will be given due consideration, provided full particulars with justification thereof, are furnished.

8.0 RATING AND OTHER PARTICULARS OF THE FUSE SWITCH

8.1 The fuse switches shall be designed for the following rating and other particulars:

(i) Type Outdoor, expulsion rewirable dropout type. (ii) Rated voltage 25 kV subject to rise up to 27.5 kV (iii) Rated current 1 Amp / 5 Amp (iv) Rated breaking capacity 5000A at a recovery voltage of 27.5 kV (v) Rated frequency 50 Hz (vi) Number of poles One

8.2 The fuse links shall be continuously rated for 1 Amp. In case of 10 kVA transformer

and 5 Amp in case of 100 kVA transformer. The fuse link rated for 1 Amp shall blow off within one second for a fault current of 10 A and fuse link rated for 5 Amp shall blow off within 0.5 sec. For a fault current of 75 Amp. The fuse link shall be of materials which effectively resist deterioration under normal climatic condition. The fuse link shall be mechanically robust to ensure that no damage results in from normal handling or operation of the associated equipment. A minimum tensile strength of 7 Kg shall be ensured, for the fuse link. The fusing element shall be protected with a strong fibre sleeve so as to prevent damage to the fuse carrier tube at

194

the time of operation. Suitable end terminals shall be crimped / soldered on fuse link to ensure its proper fixing in position. The length of fuse link shall be 650 mm.

9.0 TYPE, CONSTRUCTION AND MOUNTING OF THE FUSE SWITCH 9.1 The fuse switch shall be of robust construction ensuring no damage from normal

operation, handling and vibration and free operation at all times.

9.2 The fuse shall be of the rewirable, expulsion type in which the length of the break is increased by expulsion of part of or full fuse element and in which the arc quenching is assisted by the movement of gases from the fuse carrier. The mounting shall be such that in the event of the fuse blowing out, the fuse link or carrier drops down and hangs suspended from the lower contact.

9.3 The fuse link shall be designed for use as an isolator blade to be operated with a protable insulated operating pole from ground level. It shall also be possible to remove the fuse link bodily from the fuse switch, when it is hanging from the lower contact, with the operating pole.

9.4 The fuse carrier shall be of synthetic resin bonded glass fibre tube conforming to BS:3953-1976. The tube shall be of 500 mm length having an inside dia. of 16mm and an outside dia of 32mm.

9.5 The fuse switch shall be complete with its mounting frame. Bolts, nuts and other fasteners of 12 mm dia. and less shall be of stainless steel. Higher size of fasteners may be made of galvanised steel.

9.6 All ferrous parts shall be hot dip galvanised and other parts including top and bottom contacts shall be made of tin bronze. The zinc coating shall satisfy the requirements of IS:2633-1972 and tin bronze of IS: 306-1968

9.7 The fuse switch shall be suitable for mounting on the vertical face of a structural steel support, with four 16 mm dia. bolts spaced vertically 450 mm apart and horizontally 340 mm apart.

9.8 The fuse switch shall be provided with terminals suitable for connection to 19/2.10 mm (10.5 mm dia.) cadmium copper wire on the line side. At the load side the terminals shall cater for connection to 2 SWG (7 mm dia.) copper wire.

9.9 The fuse switch shall strictly conform to Drg. ETI/PSI/082 for general assembly and Drg. No. ETI/PSI/038 for part details. These drawings are enclosed with the specification. The workmanship shall be good and the castings of different components shall be free from any defects and shall have a good finish. The manufacturer’s monogram shall be stamped on different components for an easy identification.

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6. SUPPORT INSULATORS 6.1 The support insulators shall be of solid core construction conforming to the

provisions and requirements of IS:4318-1967, as applicable to Post Insulators. The insulators shall be procured from the approved manufacturers only.

6.2 The porcelain shall be sound, free from defects, thoroughly vitrified and smoothly

glazed. The caps shall be made of black heart malleable cast iron conforming to grade BM 340 of IS: 2108-1977 and the ferrous parts shall be hot dip galvanised.

7. OPERATING POLE 7.1 The operating pole shall be designed for opening / closing as well as removal / refixing

of the fuse carrier from ground level under live conditions of the fuse switch. 7.2 The operating pole shall have a total length of about 6 m made of four pieces with

necessary joints in brass metal caps, to facilitate quick assembly. 7.3 Suitable attachment made of aluminium alloy to engage the fuse link shall be provided

at the top end of the pole. 7.4 The main insulation in the operating pole shall comprise glass fibre insulating piece of

not less than 500 mm long at the top end, and rigidly fixed on to the supporting piece below. The remaining portion of the operating pole below the insulating piece shall be made of either Permali wood encased in PVC sleeving or synthetic resin bonded glass fibre tube coated with three coats of polyurethene. In case of Permali wood, the PVC sleeving shall maintain a firm bond with the wood base, the joint between the sleeve and the wooden pole being impervious to ingress of moisture.

7.5 The operating pole shall be robust in construction and light in weight. The complete

assembly, which shall not be too flexible, shall be capable of taking a cantilever load of 2 kg without cracking or breaking.

7.6 The operating pole shall strictly conform to Drg No. ETI/PSI/039 enclosed with the

specification. 7.7 A suitable canvas carrying case, to hold the four pieces of the pole, with a strap for

slinging, shall be provided with each operating pole for packing and transport. 8. TESTS 8.1 All the tests on the drop out fuse switch and operating pole assembly shall be carried

out at the manufacturer’s works. The electrical tests may be carried out at any

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reputed laboratory where testing facilities are available subject to prior approval of the Purchaser. The manufacturer shall arrange without making claim or charges, all the necessary apparatus, labour assistance etc. required to conduct the specified tests.

8.2 Type tests. 8.2.1 The following type tests shall be carried out on the prototype fuse switch:

(i) Visual examination and general observations.

(ii) Dimensional measurements

(iii) One-minute dry and wet power frequency withstand voltage test

(a) To earth 95 kV (rms)

(b) Across isolating distance 110 kV (rms)

(iv) Lightning impulse withstand voltage test (positive and negative polarity)

(a) To earth 190 kV (peak)

(b) Across isolating distance 235 kV (peak)

(v) Breaking capacity test at 5 kA with a recovery voltage of 27.5 kV

(vi) Test for current / time characteristics for fuse link.

8.2.2 The following type tests shall be carried out on the prototype operating pole:

(i) Visual examination and general observations.

(ii) Dimensional measurements

(iii) One-minute dry and wet power frequency voltage withstand test at 105 kV

(rms) on main insulating piece in vertical position.

(iv) Lightning impulse withstand voltage test (positive and negative polarity) at

250 kV (p) on main insulating piece in vertical position.

(v) One-minute dry power frequency voltage withstand test on permali

wood/glass fibre portion of operating pole at 40 kV (rms) across ferrules

clamped on pole at 300 mm apart.

(vi) Cantilever load test:

(a) The complete assembly of operating pole shall be subjected to a cantilever load of 8 kg on the top end, the base being clamped horizontally at intervals of 300 mm and 1000 mm from the bottom end. The deflection of the top end from the horizontal level shall be

197

measured and recorded. The operating pole should withstand this test without any permanent deformation.

(b) Base remaining clamped, the load shall then be removed from the top end. The deflection at the top end measured from the horizontal level should not exceed 300 mm.

(vii) Impact test : With a load of 8 kg tied at the top end, the completely assembled

operating pole shall be lifted up and the top of the pole swung over an angle of 460 from vertical 20 times. There should be no sign of cracking, distortion or damage at the end of the test.

(viii) Mechanical endurance test :

(a) The operating pole assembly shall be tested for mechanical endurance

by assembling and dissembling the operating 300 times each time pulling out and putting back the fuse carrier tube on to the DO fuse switch. After this test, there shall be no surface defects in the glass fibre tube. Also, no loosening of joints should take place.

(b) The cantilever load test shall be repeated after the mechanical endurance test and it shall be verified that deflection do not exceed the values measured/specified in para 8.2.2(vi) above.

(ix) Determination of weight of assembly.

8.2.3 If the prototype of the fuse switch and operating pole conforming to this specification has already been approved in connection with previous supplies to Indian Railways, fresh prototype testing may be waived if the equipment had passed the prototype tests earlier and no changes in the design or material have been made.

9. Routine test:

All the fuse switches and operating poles shall be subjected to the routine tests detailed below at the manufacturer’s works :

(i) Visual examination (ii) Dimensional measurements (iii) One-minute dry power frequency withstand voltage test on fuse switch at 95

kV (rms). (iv) One-minute dry power frequency withstand voltage test on the fibre glass

insulating piece of the operating pole at 105 kV (rms). (v) Cantilever load test on operating pole as per clause 8.2.2(vi)

9.1 Technical data and drawings: 9.2 The tenderer shall furnish guaranteed performance, technical and other particulars for

the equipment offered in the proforma attached as Annexure-A.

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9.3 The tenderers shall indicated their compliance or otherwise against each clause and sub-clause of the Technical Specification. The tenderers shall for this purpose enclose a separate statement, if necessary, indicating the annexure and clause reference and compliance or otherwise. Wherever the tenderer deviates from/the provisions of the clause, he shall furnish his detailed remarks.

(This specification supersedes specification No. ETI/PSI/14(11/78) and No. ETI/PSI/14(7/82). Encl : Annexure-A and Drawings No. ETI/PSI/032 Mod-D ETI/PSI/038 Mod-B

ETI/PSI/039 Mod-B

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Annexure –A to

Specification No. ETI/PSI/14(1/86)

SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS

Description

Unit of measurement


2. Country of origin.

3. Standard Governing Specification.

4. Manufacturer’s type and designation

5. Rated voltage

kV

6. Rated current

A

7. Rated breaking capacity

kA

8. Total operating time at the rated breaking current

ms

9. Operating time a) at 10 A for 1 A fuse link b) at 75 A for 5 A fuse link

ms ms

10. Minimum fusing current for the fuse element a) 1 A fuse link b) 5 A fuse link

A A

11. Insulation level of fuse switch a) One minute wet power frequency withstand (i) To earth (ii) Across isolating distance b) Impulse withstand (i) To earth (ii) Across isolating distance

kV (rms) kV (peak)

12. Insulator particulars

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a. Name of manufacturer b. Standard Governing Specification. c. Manufacturer’s type and designation d. One minute dry power frequency withstand kV (rms) e. One minute wet power frequency withstand kV (rms) f. Impulse withstand

i) Positive polarity ii) Negative polarity

kV (peak)

g. Minimum failing loads i) In tension ii) In bending iii) In torsion iv) In compression

kgf kgf.m kgf.m kgf

h.

Weight of each insulator kg

13. Materials of fuse switch contacts

14. Temperature rise of contact at rated current above ambient

ºC

15. Minimum clearance in air a) Across isolating distance b) Live parts to earth.

16. Type of terminal connectors 17. Type of fuse switch

(whether outdoor / dropout, expulsion type).

18. Fuse link particulars i. Name of manufacturer

ii. Standard Governing Specification. iii. Manufacturer’s type and designation iv. Rated current v. Rated breaking capacity at a recovery voltage of

27.5 kV.

vi.

Minimum tensile strength in kg.

Kg

19. Material of fuse carrier tube and the name of its manufacturer

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20. Weight of fuse switch assembly

kg

21. Particulars of operating pole:

a. Name of manufacturer b. Manufacturer’s type and designation c. Material of insulating pieces

i) Top piece ii) Other pieces

d. Material of top attachment e. Insulation strength of insulating piece:

i) One minute wet power frequency withstand ii) Impulse withstand

kV (rms) kV (peak)

f. One minute dry power frequency withstand across ferrules 30 cm apart on permali wood / glass fibre portion on the pole.

kV (rms)

g. Weight of the operating pole assembly.

kg.

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ADDENDUM / CORRIGENDUM SLIP NO. 1 OF TRACTION INSTA LLATION, DIRECTORATE, SPECIFICATION NO. ETI/PSI/14 (1/86) FO R 25 kV DROPOUT FUSE SWITCH AND OPERATING POLE. The existing paras 8.2.2 (vi) & (viii) at page 7 shall be reread as under:- 8.2.2 (vi) Cantilever load test:-

a) The complete assembly of operating pole shall be subjected to a cantilever load of 2 kg on the top end, the base being clamped horizontally at intervals of 300 mm and 1000 mm from the bottom end. The deflection of the top end from the horizontal level shall be measured and recorded. The operating pole should withstand this test without any permanent deformation.

b) Base remaining clamped, the load shall then be removed from the top end.

The deflection at the top end measured from the horizontal level should not exceed 300 mm.

8.2.2 (viii) Mechanical endurance test:-

a) The operating pole assembly shall be tested for mechanical endurance by assembling and disassembling the operating pole 200 times, each time putting out and putting back the fuse carrier tube on to the DO fuse switch. After this test, there shall be no surface defects in the glass fibre tube. Also, no loosening of joints should take place.

b) The cantilever load test shall be repeated after the mechanical endurance test

and it shall be verified that deflection do not exceed the value measured / specified in para 8.2.2 (vi) above.

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RDSO Specification No. ETI / PSI / 14 / (1/86) 25 kV Dropout Fuse Switch and operating pole. The following amendments are made in addition to the addendum and corrigendum slips issued to the specification. Sl.No. Para No. Amendment 1. Para 2.2 Minimum Temperature of air in Shade : Substitute 0ºC with 5ºC Maximum wind pressure : Substitute 200 kg / m2 With 112.5 kg / m2

2. Para 8.2.3 In line 5, delete “Indian”

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RESEARCH DESIGNS AND STANDARDS

ORGANISATION

SPECIFICATION

FOR

25 kV, 240V, 5kVA AND 10KVA, & 50 KVA, 50Hz. SINGLEPHASE, OIL FILLED

AUXILIARY TRANSFORMERS

No. ETI / PSI / 15 (08 /2003)

205


MINISTRY OF RAILWAYS, GOVERNMENT OF INDIA,

RESEARCH DESIGN AND STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW 226 011.

SPECIFICATION

FOR

25 kV / 240 V, 5 KVA AND 10 KVA, 50 KVA, 50 Hz. SINGLE PHASE, OIL FILLED

AUXILIARY TRANSFORMERS

FOR

RAILWAY AC TRACTION SYSTEM


RESEARCH DESIGN AND STANDARDS ORGANISATION MINISTRY OF RAILWAYS, GOVERNMENT OF INDIA,


206

Specification No. ETI/PSI/15 (08/2003)

For 25 KV/ 240 V, 5 ,10,25 and 50 KVAAuxiliary Transformer.


25 KV/ 240 V, 5 KVA ,10 KVA, 25 KVA & 50 KVA OIL FILLED AUXILIARY TRANSFORMER.

1.0 SCOPE 1.1 This specification applies to 25 KV/ 240 V, 50 Hz a.c. (i) 5 kVA and (ii) 10 kVA (iii)

25 KVA and ( iv) 50 KVA oil filled single phase, auxiliary transformer (AT) for installation at 220/27 kV, 132/27 kV, 110/27 kV and 66/27 kV Railway’s traction substations, switching stations and other outdoor locations. The voltage on the primary side will vary from 19 kV (minimum) to 27.5 kV (maximum) and the AT should deliver the rated power within this specified voltage range at any of the provided taps.

1.2 The AT shall be complete with all parts, fittings and accessories necessary for its

efficient operation. All such parts, fittings and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not.

1.3 This specification supersedes the earlier specification no. ETI/PSI/15 (11/92) with

A&C Slip No.1 to 2 which was meant for 5 kVA, 10 kVA and 50 kVA AT. 1.4 The AT shall be erected by the Purchaser/Indian Railways. However, in case, a

defect/deficiency is noticed, the manufacturer / successful tenderer will have to depute his engineer for necessary remedial action without any cost to the Railways.

2.0 GOVERNING SPECIFICATION 2.1 The AT shall, unless otherwise specified, conform to the following standards and

codes of practices (latest version) which shall be applied in the manner altered, amended or supplemented by this specification and Indian Electricity Rules, wherever applicable:

1. IS : 5 Colours for ready mixed paints and enamels.

2. IS : 226 Specification for structural steel (standard quality) 3. IS : 335 Specification for New Insulating Oils.

207

4. IS : 1271 Classification of insulating materials for electrical machinery and apparatus in relation to their thermal stability in service.

5. IS : 1367 Technical supply conditions for threaded steel fasteners. 6. IS : 1554 Specification for PVC insulated (heavy duty), (Part I) electrical cables for working voltage upto and including 1100 volts. 7. IS : 1570 Schedule for wrought steel for general (Part V) engineering purposes.

8. IS : 1576 Specification for solid press board for electrical

purposes. 9. IS : 1866 Code of practice for maintenance and supervision of insulating oil in service. 10. IS : 2071 Methods of high voltage testing. 11. IS : 2074 Ready mixed paint, air drying red oxide zinc chrome, priming. 12. ISO/EN : 12944 Protective Paint Systems. 13. IS : 2026 Specification for Power Transformers.

(Part I to IV) 14. IS : 2099 Specification for bushings for alternative voltages above 1000 V. 15. IS : 2927 Brazing alloys. 16. IS : 3024 Specification for electrical steel sheets (oriented). 17. IS : 3347 Dimensions for porcelain transformer bushings. 18. IS : 3639 Specification for fittings and accessories for power transformer.

19. IS : 4253 pecification for Cork and Rubber. (Part II) 20. IS : 5561 pecification for Electric Power connectors.

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21. IS : 5621 Specification for Hollow insulators for use in electrical equipments. 22. IS : 6600 Guide for loading of oil immersed transformers. 23. IS : 8570 Press paper for electrical purposes. 24. IS : 8572 Paper covered flexible/stranded copper

conductor for transformer leads. 25. IS : 9224 Specification for low voltage fuses. 26. IS : 10028 Code of practice for selection, installation and (Part I toIII) maintenance of transformers.

27. IEC : 76 Power Transformers.

28. IEC : 137 Bushing for alternating voltage above 1000 V.

29. IEC : 815 Guide for the selection of insulator in respect of polluted conditions.

2.2 In case of any conflict between the contents of the above specifications and the

contents of this specification, the latter shall prevail. 2.3 Any deviation from this specification, proposed by the tenderer, intended to improve

the performance, utility and efficiency of the equipment, will be given due consideration, provided full particulars of the deviation with justification thereof, are furnished. In such a case, the tenderer shall quote according to this specification and the deviation, if any, proposed by him shall be quoted as an alternative(s).

3.0 ENVIRONMENTAL CONDITIONS 3.1 The AT shall be suitable for outdoor use in moist tropical climate and in areas

Subject to heavy rainfall, pollution due to industry and marine atmosphere and severe lightning. The limiting weather conditions which the AT has to withstand in service are indicated below: i) Maximum ambient air temperature 50 °C. ii) Average ambient air temperature over 35 °C. a period of 24 h. iii) Maximum relative humidity 100 % iv) Annual rainfall Raining from 1750 mm to

6250 mm.

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v) Maximum number of thunder storm 85 days per annum.

vi) Maximum number of dust storm 35 days per annum.

vii) Number of rainy days per annum 120 viii) Basic wind pressure 200 kgf/mm2

ix) Altitude Not exceeding 1000 m.

3.2 The AT shall be subjected to vibrations on account of trains running on nearby railway

tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 to 70 ms lies in the range of 30 to 150 microns at present, with the instantaneous peak going upto 350 microns. These vibrations may become more severe as the speeds and loads of trains increase in future.

4.0 SERVICE CONDITIONS 4.1 The AT shall be suitable for pole mounting along the railway track for supplying

power to electric signaling and/or substation/switching station loads. 5.0 RATING AND GENERAL DATA

5.1 The rating and other particulars of the auxiliary transformer shall be as follows:

(i) Type Double wound, single phase, ONAN(oil natural air natural)

cooled, step-down transformer for outdoor installation.

(ii) Rated voltage for primary winding a)Nominal Voltage 25kV b)Minimum Voltage 19kV c)Maximum Voltage 27.5kV iii) Rated voltage for secondary 240 V.

winding.

iv) Rated current – at rated nominal voltage (a) For primary winding (i) 0.2 A for 5 kVA. (ii) 0.4 A for 10 kVA. (iii) 1.0 A for 25kVA (iv) 2.0 A for 50kVA

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(b) For secondary winding (i) 21 A for 5 kVA. (ii) 42 A for 10 kVA. (iii) 105 A for 25kVA (iv) 210A for 50kVA

v) The maximum current at the lowest primary voltage at extreme tap position must be worked out and the conductor sizes must be decided accordingly.

vi) Rated frequency 50 Hz +/- 3%.

vii) Rated power at rated nominal

voltage (i) 5 kVA (at all tap positions) (ii) 10 kVA

(iii) 25kVA (iv) 50kVA

viii) Insulation level of winding Primary Secondary

(a) Rated lightning impulse 190 kV -- withstand voltage peak

(b) Rated short duration power 70 kV rms 3 kV rms frequency withstand voltage

(c) Rated induced over voltage 80 kV rms

ix) Tappings Off-circuit tap changer to give the rated secondary winding voltage for a primary winding voltage variation of plus 5% to minus 10% from nominal voltage of 25kV in steps of 5%. Tapping may be provided either on primary or secondary windings. All tappings shall be capable of carrying maximum full load current continuously at lowest primary voltage.

x) Polarity Subtractive

xi) Temperature rise limits The temperature rise over an ambient

temperature of 50ºC at maximum full load current at lowest primary voltage shall not exceed the value indicated below: a) Winding : 50ºC (measured by the resistance method).

211

b) Insulating oil : 40ºC (measured by thermometer).

c)Current carrying parts in air : 40ºC.

d)Hot spot temperature : not to exceed 115ºC.

xii) Impedance voltage at rated 5 %.

current at 75ºC

xiii) Type of cooling “ONAN” xiv) Temperature class of insulation Class A for all the windings.

xv) Current density for primary & 2.5 A/mm2

secondary windings (max).

xvi) Maximum permissible losses

a) No load loss (i) 50 W for 5 kVA (at max. primary voltage of 27.5kV) (ii) 60 W for 10 kVA. (iii) 80W for 25kVA (iv) 150 W for 50kVA b) Load loss at 75ºC (i) 200 W for 5 kVA (at max. current at lowest primary voltage of 19kV) (ii) 300 W for 10 kVA. (iii)500W for 25kVA (iv)950W for 50kVA

xvii) Minimum creepage distance (i) 900 mm for 35 kV class, of the porcelain housing (ii) 90 mm for 3.6 kV class.

xviii) Acoustic sound level when not more than 75 db at a distance of

energized at rated voltage 0.3 m from the transformer. And at no load. (xix) Maximum permissible efficiency At 50% of rated load. 6.0 SALIENT DESIGN FEATURE 6.1 General Construction.

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6.1.1 The dimensions of the 5kVA, 10kVA, 25kVA and 50kVA auxiliary transformers shall not exceed those shown in drawing at Annexure 2. The AT shall be provided with two hot dip galvanized channels at the bottom of the steel enclosure in order to make it suitable for mounting on the mast and the disposition of primary bushing and secondary bushings shall be as shown in the above drawing. The fixing hole distances and slot dimensions on the transformer base channels shall be strictly adhered to.

6.1.2 The overall dimensions of the AT shall be kept, as low as possible and in any case shall not exceed the values given below.

(i) Length x Width : 650 x 500 mm for 5 and 10kVA( Also shall not exceed the values as per drawing at Annexure -3) (ii) Length x Width : 825 x 700 mm for 25kVA( Also shall not exceed the values as per drawing at Annexure -3) (iii) Length x Width : 1000 x 900 mm for 50kVA( Also shall not exceed the values as per drawing at Annexure -3) (iv) Height of the top most point of the primary bushing (mm) - 1700 (v) Height of the top most point of any part including conservator tank should not exceed 1950mm

6.2 Transformer tank. 6.2.1 The tank for the auxiliary transformer shall be constructed from good commercial

grade low carbon steel suitable for welding with a single tier construction, so shaped as to reduce welding to the minimum while fabricating. The tank shall be adequately strengthened to permit hoisting of the transformer filled with oil by a crane or other means.

6.2.2 Welded joints shall be made using the latest welding techniques. 6.2.3 The tank shall be provided with lifting lugs suitable for lifting the transformer filled

with oil. The lifting lugs shall be provided on the side walls of the tank. Separate lifting arrangement for the tank cover and the core shall be provided.

6.2.4 The rubberised cork / nitrile gaskets or any other gaskets shall conform to IS

: 4253 (Part II). 6.2.5 Silicagel breather shall be suitably clamped to the tank. Silicagel breather shall have

flange type of connecting arrangement. The silicagel container shall be made of a seamless tough acrylic tube and so designed as to facilitate easy replacement and filling and removal of silicagel. The colour of silicagel shall be visible to a person standing on the ground.

6.2.6 Auxiliary transformer shall be provided with the channel at the bottom of the tank in

order to make it suitable for pole mounting as shown in the drawing at Annexure-3.

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The centre to centre fixing hole distance and slot dimentions on the base channel shall be rigidly complied with. Undirectional rollers shall also be provided on the transformers base channel.

6.3 Core. 6.3.1 The core shall be made of high permeability cold-rolled grain oriented / non- ageing

electrical silicon steel laminations conforming to IS:3024. The flux density in any part of the core and yoke with the primary winding excited at the rated voltage and rated frequency shall not exceed 1.55 tesla.

6.3.2 The laminations used for stacking the core, shall be free from defects due to storage /

atmospheric effects. Both sides of the laminations shall be coated with suitable insulation, capable of withstanding stress relief annealing. In assembling the core, air gaps shall be avoided.

6.3.3 The core shall be electrically connected to the tank to drain off any electro static

potential that may have built up. 6.3.4 Yoke / core clamping bolts shall have adequate threaded length beyond the face of the

nuts for tightening at a later stage, if need arises. Each of the core clamping bolts and the core clamping frame work shall be insulated from the core laminations and tested after completion of the core assembly to ensure that they withstand a voltage of 2 kV r.m.s, with respect to core for a duration of 60 s.

6.4 Windings. 6.4.1 Primary and secondary windings shall be of spiral / helical type and shall have class

‘A’ insulation. These shall be made of continuous electrolytic copper conductor. 6.4.2 Normally, no joint shall be used in the winding conductor. If a joint becomes

inescapable, it shall be brazed with high silver alloy grade Ba Cu Ag6 conforming to IS : 2927 or electrically butt-welded.

6.4.3 The auxiliary transformer windings shall have the following insulating levels:

S.No. Primary Secondary

a) Rated voltage between winding 25 kV 240 V and earth.

b) Rated short duration power 70 kV rms 3 kV rms frequency withstand voltage.

c) Rated lightening impulse 190 kV peak -- withstand voltage.

d) Induced over-voltage with stand 80 kV rms --

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6.4.4 As the AT is subject to frequent short circuit currents while in normal operation, the

winding shall be specially designed and suitably brazed to withstand electro magnetic forces without any injury. Windings shall be so assembled as to be magnetically balanced with respect to each other to minimize mechanical stresses.

6.4.5 The winding assembly shall be thoroughly dried in vacuum, shrunk to final dimensions

and impregnated under vacuum with insulating oil conforming to IS : 335. 6.4.6 All leads and connections shall be mechanically strong, adequately insulated, protected

against mechanical injury and rigidly clamped to withstand dynamic stresses due to short circuit.

6.5 Bushings and Terminal Arrangement. 6.5.1 The bushings shall comply with IS : 2099 and IS : 3347. The line terminal of the

primary winding shall be brought out through 36 kV class bushing for connection to the overhead equipment and the neutral terminal brought out through a 3.6 kV class bushing and connected to the tank externally by means of a suitable tin coated copper link. The steel enclosure of the AT shall be connected to earth during service.

6.5.2 The 3.6 kV bushing and connection of the link to the tank shall be covered by a sheet

steel of not less than 2 mm thickness welded on to the tank and should have a captive bolted cover.

6.5.3 The porcelain housings of both bushing shall comply with the requirements laid down

in IS : 5621 and shall be of a single piece construction i.e. there shall be no joint in the porcelain housing. The shed profile shall have a lip at the extremities, but free from ribs on the underside so as to avoid accumulation of dust and pollutants and to permit easy cleaning.

6.5.4 The design of the bushing shall be such that stresses due to expansion and contraction

in any part of the bushing shall not lead to its deterioration. 6.5.5 The bushing shall be free from corona. 6.5.6 Primary and secondary bushings shall be provided with identical tinned copper stems

of 20 mm diameter for 36 kV class bushing and 12 mm diameter for 3.6 kV class bushing. The stem shall be threaded to metric size at suitable places as per IS : 1367.

6.5.7 The bushings shall withstand the following test voltages.

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S.No.

Primary (line end)

Secondary (including neutral end

of primary winding bushing)

(a) Highest voltage for equipment Um.

36 kV rms 3.6 kV rms

(b) Rated short duration

wet power frequency withstand voltage.

70 kV rms

10 kV rms

(c) Rated lightening impulse 190 kV peak 40 kV peak withstand voltage.

(c) Minimum creepage distance 900 mm 90 mm

6.5.8 The adjustable arcing horns shall be provided on the primary bushing side. The horn gap setting shall be variable between 125 to 250 mm.

6.5.8 The secondary terminal box shall be suitable for following cable sizes for the

different ATs.

S.No. AT Type Cable Size 1 5 KVA 2X25 Sq.MM Al. Cable 2 10 KVA 2X70 Sq.MM Al. Cable 3 25 KVA 2X150 Sq.MM Al. Cable 4 50 KVA 2X300 Sq.MM Al. Cable

6.5.10 The primary and secondary bushings and terminal connectors shall be procured from

Research Designs and Standards Organisation’s (RDSO) approved manufacturers only.

7.0 INSULATING OIL 7.1 The auxiliary transformers shall be supplied complete with insulating oil conforming to

IS : 12463. The transformer shall be shipped with windings and core completely under oil. The insulating oil shall be procured from the manufacturers approved by RDSO. The successful tenderer / manufacturer shall submit test certificates as per IS : 12463 for oil.

7.2 The Characteristics of insulating oil before energisation of the new AT and during its

maintenance and supervision in service shall conform to the parameters stipulated in IS : 1866.

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8.0 FASTENERS 8.1 All fasteners of 12 mm diameter and less, exposed to atmosphere shall be of stainless

steel and those above 12 mm diameter shall preferably be of stainless steel or of mild steel hot dip galvanised. The material of the stainless steel fasteners shall conform to IS: 1570 (Pt.V) Grade 04, Cr 17 Ni 12 Mo 2.

9.0 PAINTING 9.1 All steel surfaces in contact with insulating oil shall be painted with heat resistant, oil

insoluble insulating varnish. 9.2 All steel surfaces exposed to weather shall be properly descaled/grit blasted. The

epoxy and polyurethane protective paints as per ISO/EN 12944 have to be provided for proper protection against corrosive and coastal environments and give life of approx. 12-15 years. The external surfaces of the AT shall be given first coat of epoxy zinc rich (having minimum 83% metallic zinc) primer (50 micron thickness), intermediate coat of epoxy chemical and corrosion resistant paint (100 micron thickness) and final coat of polyurethane paint (50 micron thickness). The total dry film thickness of the paints shall be minimum 200 micron. The shade of paint shall be garay as shade 631 of IS : 5

10.0 SOURCES OF SUPPLY FOR WINDING WIRE, GASKETS AND ‘O’ RINGS. 10.1 The winding wire, gaskets and ‘O’ rings used in the manufacture of the AT shall be procured only from suppliers having BIS certification for the items. 10.2 The successful tenderer / manufacturer shall be required to furnish the following

information in respect of winding wire, gaskets and ‘O’ rings:

(i) Source of supply

(ii) Reference to standard specification to which the material conforms.

(iii) Reports of type tests carried out in terms of relevant Indian Standard Specification.

11.0 RATING PLATE 11.1 The auxiliary transformer shall be provided with a rating plate (both in Hindi and

English) of weather proof material, fitted in a visible position, showing the items indicated below:

(i) Type of transformer

(ii) Governing specification

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(iii) Manufacturer’s name (a) Manufacturer’s serial number

(iv) Year of manufacture (v) Rated output (vi) Rated frequency (vii) Highest voltage for equipment (viii) Rated voltage

(a) Primary (b) Secondary

(ix) Rated current (a)Primary

(b) Secondary (x) Maximum temperature rise over an ambient of 50 Deg. C


(xi) Total weight (xii) Class of insulation (xiii) Insulation levels (xiv) Connection diagram indicating the taps.

The letters / figures on the plate shall be indelibly marked by etching, engraving or stamping.

12.0 FITTINGS AND ACCESSORIES 12.1 The following fittings and accessories shall be supplied with each AT :

(i) Conservator with oil filling hole and cap (ii) Drain hole with plug for conservator

(iii) Oil level indicator (iv) Silicagel breather with oil seal

(v) Upper filter valve (vi) Lower filter cum drain valve (vii) Adjustable arching horn of range 125 – 250 mm (viii) Rating plate with connection diagram indicating the taps. (ix) Lifting lugs (for complete transformer)

(x) Air release device (xi) Thermometer pocket (xii) Lifting lugs (for cover, core and windings) (xiii) Oil sampling valve (20 mm) with plug (xiv) Two earthing terminals (xv) Terminal connectors for both HV & LV terminals (xvi) Off circuit tap changer with locking arrangement and tap position indicator.

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13.0 DRAWINGS 13.1 A format of the title sheet to be adopted by the successful tenderer / manufacturer for

preparation of the drawings is attached at Annexure- 4.. 13.2 The successful tenderer / manufacturer shall submit for approval the following

detailed dimensioned drawings to the Purchaser / Director General (Traction Installation), Research, Design and Standards Organisation (DG(TI), RDSO) Lucknow as per Indian Railway .Standards in sizes of 210 mm x 297 mm or any integral multiple thereof.

(bb) Outline general arrangement of the AT showing plan, front elevation, side elevationdetails as well as salient guaranteed particulars indicated therein. (ii) Internal arrangement of the AT indicating primary and secondary bushing lead

connections, core to core and core to tank earthing. (iii) Cross sectional view of the core and windings with material specifications. (iv) Details of ‘O’ rings and gaskets. (v) Details of oil level indicator. (vi) Bushing for primary side including cross sectional view, shed profile, arcing horns and salient electrical and mechanical characteristics. (vii) Bushing for secondary side including cross sectional view, shed profile and

salient electrical and mechanical characteristics. (viii) Terminal connectors for primary and secondary side bushing terminals. (viii) Rating plate both in English and Hindi with connection diagram indicating

the taps. (x) Details of off-circuit tap changer with locking arrangement. (xi) Details of silicagel breather. (xii) Any other drawing considered necessary by the successful tenderer /

manufacturer and / or purchaser / (DG(TI)RDSO), Lucknow. 13.3 The provisionally approved drawings shall be modified, if need be, as a result of

changes necessitated during or as a result of type tests or as desired by the purchaser / FOR DIRECTOR GENERAL/TI-IV (TI), RDSO, Lucknow. The modification shall be first got approved by the Purchaser / FOR DIRECTOR GENERAL/TI-IV (TI), RDSO, Lucknow and then incorporating the drawing and each such modification shall be got signed by the authority concerned on the drawings. If there are no modifications at all the drawings shall be finally approved.

13.4 Six copies of approved drawings alongwith two sets of reproducibles shall be sent to

each consignee(s), as indicated in the purchase order. Besides two copies of drawings alongwith one set of reproducible and on floppy along with hard copy (in Autocad 2000) after final approval of the drawings shall be supplied to shall be supplied to DIRECTOR GENERAL/TI-IV (TI), RDSO, Lucknow (INDIA)

219

13.5 The successful tenderer / manufacturer shall also be required to supply at least six copies of the Instruction and Maintenance Manual for AT to each consignee and two copies to DG (TI) RDSO, Lucknow – 226 011.

14.0 TESTING OF TRANSFORMER 14.1 General

Once a purchase order is placed for supply of a auxiliary transformer the designs and drawings shall be furnished to the Purchaser/DG (TI), RDSO, Lucknow as the case may be within the period stipulated in the order. Only after all the designs and drawings have been approved for prototype tests and a written advice given to that effect, shall the successful tenderer/manufacturer take up manufacture of the prototype of the transformer. It is to be clearly understood that any change or modification required by the above authorities to be done in the prototype shall be done expeditiously, not withstanding approval having already been given for the designs and drawings. Such change or modification shall be incorporated in the drawing as indicated in Clause 13.0.


testing of the prototype, the successful tenderer/manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the tests and the number of days required to complete all the tests at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the purchaser reserves the right to conduct any additional test(s), besides those specified herein, on any equipment / item so as to test the equipment / item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and representative of the Purchaser / DG (TI), RDSO, Lucknow, during the process of testing as regards the procedure for type tests and/or the inspection and acceptability of the results of type tests, it shall be brought to the notice of the Purchaser / DG (TI), RDSO, Lucknow, as the case may be, whose decision shall be final and binding. Only after the prototype transformer is completed and ready in each and every respect, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with atleast 15 days notice for the purpose.

14.1.3 In the event of the tests not being carried through to completion at one stretch and if

due to any reason attributable to the successful tenderer / manufacturer and it is required for the representative of the purchaser / DG (TI) RDSO to go again or more number of times to the works of the successful tenderer / manufacturer or other place(s) for continuing and / or completing the tests on the prototype(s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser / DG (TI) RDSO, Lucknow, the costs for the representative having to visit to the works or other place(s) for the tests more than once. The costs as claimed by the Purchaser / DG (TI), RDSO, Lucknow, shall be paid through a demand draft to the concerned

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accounts officer of the Purchaser / DG (TI), RDSO, Lucknow, as shall be advised to the successful tenderer / manufacturer.

14.1.4 The type tests shall be carried out in accordance with “Quality plan for Auxiliary

Transformer prototype Testing” and with the relevant standards as modified by the specification where ever applicable, at the works of the successful tenderer/manufacturer or at a reputed testing laboratory in the presence of the authorized representative of the purchaser FOR DIRECTOR GENERAL /TI, RDSO, Lucknow.

14.2 Tests during manufacture.

Following type tests shall be carried out on the prototype unit during manufacture, (a)Vacuum Test (b)Pressure Test.

14.2.1 Vacuum Test. The AT tank only shall be tested at a vacuum of 3.33 kN/m2 (0.033 kg /cm2) for 60 min. The permanent deflection of flat plates after release of vacuum shall not exceed the value indicated below:

-------------------------------------------------------------------------------------------------- Horizontal length of Permanent deflection flat plate mm. -------------------------------------------------------------------------------------------------- Upto and including 750 mm 5.0 751 mm to 1250 mm 6.5 1251 mm to 1750 mm 8.0 1751 mm to 2000 mm 9.5 ---------------------------------------------------------------------------------------------------

14.2.2 Pressure Test

Every AT tank and conservator tank shall be subjected to an air pressure corresponding to twice the normal static level of oil or to the normal static level of oil pressure plus 35 kN/m2 (0.35 kg /cm2) whichever is lower, as measured at the base of the tank. The pressure shall remain constant for 1 h to indicate that there is no leakage from any point.

14.3 Type Tests.

The following type tests shall be carried out on the prototype at the works of the successful tenderer / manufacturer or at any reputed laboratory in the presence of the representative of the purchaser / DG (TI) RDSO, Lucknow, and in accordance with the relevant specifications – altered, amended or supplemented by this specifications.

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i) Temperature rise test. ii) Lightening Impulse withstand voltage test. ii) Short circuit test. iii) Type tests on accessories

14.3.1 TemperatureRrise Test

The temperature rise test shall be done in accordance with clause 4 of IS : 2026 (Part II). The test shall be done continuously without any interruption due to power supply failure. In case interruptions of power supply do take place for some reason, then the entire test shall be repeated after steady state conditions are attained.

14.3.1.1 During the temperature rise test, the following shall be ensured:

(i) The ambient temperature shall be measured as per clause 4.1 of IS:2026(Part II).

Only alcohol in glass thermometers shall be used for the measurement.

(ii) The winding temperature shall be determined by the resistance method only. (iii) The temperature of the top oil shall be measured by an alcohol in glass

thermometer placed in an oil filled thermometer pocket. (iv) The temperature of the hot-spot in the winding shall be the sum of the

temperature of the top oil and 1.1 times the temperature rise of the winding above the average oil temperature.

14.3.1.2 The test shall be carried out as described below :

i) A quantum of power equal to the sum of the measured losses viz. no load and load losses at maximum current, achieved at lowest primary voltage of 19 kV and at appropriate tap, corrected to 75ºC plus 10% of such sum shall be fed to the primary winding of the transformer with the secondary winding short circuited.

ii) The losses so fed to the transformer shall be continuously maintained till

such time as the steady state temperature is reached i.e. the top oil temperature rise does not vary by more than 1ºC during four consecutive hourly readings.

iii) On attaining the steady state temperature, the current in the primary

winding of the transformer shall be brought to the rated maximum current achieved at lowest primary voltage 19 KV which shall be maintained for 1 h. At the end of the period the power supply to the

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transformer shall be switched off and the time of switching off recorded.

iv) The measurement of hot resistance shall commence as soon as is

possible after switching off. The first reading of the resistance shall be taken before the expiry of 90 s from the instant of switching off and the first 10 readings shall be taken at intervals of 15 s apart. Thereafter, another 10 readings shall be taken at intervals of 30 s apart.

v) The time at which each of the resistance values is read shall also be

recorded.

vi) The temperatures of the ambient, top oil and radiator inlet / outlet shall also be recorded at half hourly intervals throughout the test starting from the instant power supply is switched on to commence the test till it is switched off.

14.3.2 Lightning Impulse test

This test shall be done as per Clause 12 of IS: 2026 (Part-III). The test impulse shall be a full standard lightning impulse i.e. 1.2 ± 30% / 50 ± 20% µs. the voltage shall be applied to the line terminal of the primary winding with the neutral terminal of the winding earthed through a current measuring shunt. The tank and the terminals of the secondary winding shall be earthed. The oscillographs for voltage as well as neutral current shall be recorded. The AT shall withstand a lightning impulse of 190 kV peak.

14.3.3 Short circuit test

The short circuit test shall be done in accordance with clause 16.11 of IS : 2026 (Part I).

14.3.4 Type Tests on Accessories The type tests on bushings, terminal connectors and other accessories shall be done as per the relevant specifications.

14.4 In addition to the above all routine tests detailed in clause 14.7 below shall also be

carried out on the prototype. 14.5 If the prototype of an AT conforming to this specification has already been approved in

connection with previous supplies to Indian Railways, fresh testing of prototype of the auxiliary transformer may be waived at the discretion of the purchaser, provided that no changes whatsoever in the design or materials used have been made. However, the purchaser reserves the right to test an AT against any purchase order if he deems it necessary to do so in the light of experience gained from previous supplies.

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14.6 Only after approval of original tracings of drawings incorporating changes, if any, as a result of the type tests and clear written approval of the results of the tests on the prototype is communicated by the Purchaser / Director General (TI), Research Designs and Standards Organisation to the successful tenderer / manufacturer, shall be take up bulk manufacture of the auxiliary transformer, which shall be strictly with the same materials and process as adopted for the prototype. In no circumstances shall materials other than those approved in the design / drawings and/or during the prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

14.6.1 The prototype approval shall be accorded after conducting all the type tests (clause

14,3) and routine tests (clause 14.7) stipulated under this specification and in TIQ 0006 Rev.1 (Quality Plan for Auxiliary Transformer Prototype Testing). The validity of the Prototype approval shall normally be for a period of two years.

14.7 Routine Tests

Every AT shall be subjected to the routine tests in accordance with relevant parts of IS : 2026 in the presence of the Purchaser’s representative.

i) Visual Examination ii) Verification of terminal markings and polarity iii) Measurement of voltage ratio on all tap positions iv) Measurement of winding resistance iv) Measurement of insulation resistance v) Measurement of impedance voltage on principal tap, short circuit impedance

and load loss. vi) Measurement of no load loss and current vii) Induced over voltage withstand test for primary winding viii) Separate source power frequency withstand voltage test.

14.7.1 Visual examination

A general examination shall be made to check that the AT conforms to the approved drawings, various items are accessible for maintenance, the quality of workmanship and finish are of acceptable standards and all parts, fittings and accessories are provided.

14.7.2 Measurement of winding resistance

The resistance of the windings shall be measured and computed at 75ºC.

14.7.3 Measurement of voltage ratio Voltage ratio of primary and secondary winding shall be measured on all tap positions.

14.7.4 Verification of terminal markings and polarity

The markings of the terminals and the polarity shall be verified.

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14.7.5 Insulation Resistance

The insulation resistance of each of the windings with respect to the earth and with respect to each other shall be measured by using 2.5 kV megger.

14.7.6 Measurement of impedance voltage, short circuit impedance and load losses.

Load losses shall be measured with rated maximum current achieved at lowest primary voltage of 19 kVat ambient temperature and computed at 75ºC. The percentage impedance voltage at principal tap shall be measured with rated current, (copy of above) at ambient temperature and computed at 75ºC.

14.7.7 Measurement of No-load loss and current

No-load loss and current referred to the primary winding shall be measured at maximum rated voltage of 27.5 KV.

14.7.8 Induced over voltage withstand test

The secondary winding shall be fed at a convenient voltage and frequency, so as to obtain 80 kV between the primary terminals which shall be kept open circuited with one terminal earthed. Duration of the test at full test voltage shall be 60 sec for any test frequency upto and including twice the rated frequency. When the test frequency exceeds twice the rated frequency, the duration of the test in second shall be:

120 x Rated Frequency --------------------------- Test Frequency

But not less than 15 s. 14.7.9 Separate source power frequency withstand voltage test

This test shall be done as per clause 10 of IS : 2026 (Part III). A voltage of 3000V shall be applied between line terminal of the secondary winding, the other terminal of the primary winding, the core, the frame and the steel enclosure of the transformer, connected together and then to earth.

15.0 INFORMATION TO BE GIVEN WITH THE TENDERER 15.1 The tenderer shall furnish along with his offer, in the performa at Annexure-I, the

Schedule of Guaranteed Performance and other particulars (SOGP, Part-I)) for the AT. The particulars shall be correct and complete in all respects. The values / information given in this SOGP, Part-I, will be used for technical evaluation of the tender.

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15.2 Only the successful tenderer shall furnish the consolidated information as given in the proforma at Annexure-2, the schedule of Guaranteed Performance, Technical and Other Particulars (SOGP, Part-II) for the AT. This SOGP, Part-II will have to be approved by the indenting Railway / RDSO.

15.3 The tenderer shall specifically indicate in a “statement of compliance” attached with

the offer his compliance with each and every clause of this specification. In case the tenderer wishes to deviate from any clause of this specification he may do so giving reference to the clause(s) with the reasons / justification for the deviation. This shall be in the form of a separate statement called the “statement of deviation”. If there is no deviation at all, a separate “NIL” “Statement of Deviation” shall be attached with the offer. If the “Statement of Compliance” and “Statement of Deviation” are not attached with the offer, it is not likely to be considered for the reason that it is an incomplete offer which can not be properly evaluated and compared with other offers, if any.

15.4 The tenderer shall furnish the following drawings along with the offer:

i) Outline general arrangement drawing giving the overall dimensions of the AT. ii) Rating and diagram plate. iii) Internal arrangement of the transformer including cross-sectional views.

15.5 The tenderer shall furnish the following documents as a part of the tender documents.

i) Quality Assurance Plan for the tendered AT ii) ISO certification regarding quality system and R&D facilities. iii) List of essential plants, machinery and testing facilities and should conform to

the P&M as stipulated in RDSO’s STR No.019. iv) Up-dated calibration certificate for the testing equipment. v) Type test reports for the relevant rating for the tendered AT.

16.0 SPARES

16.1 Wherever required, the tenderer shall quote apart from main equipment, separately for recommended spares required for five years operation. 16.2 The tenderer shall also quote separately for the following essential spares:

i) 36 kV bushing. ii) Primary terminal connector

17.0 AFTER SALES SERVICE

17.1 The successful tenderer shall make necessary arrangements for closely monitoring the performance of the auxiliary transformers through periodical (preferably once in two months during the warranty period) visits to the location where they have been erected for observations and interaction with the operating and maintenance personnel of the Indian Railways. Arrangements shall also be made by the successful tenderer for emergency / standby spare parts being kept readily available to meet exigencies

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warranting replacement so as to keep theAauxiliary Transformer in service with least down time.

The successful tenderer / manufacturer shall respond promptly and in a workman like

manner to any call given by Indian Railways for any assistance by way of attending to failures, investigation into the causes of failures including tests, if any, to be done and such other items with a view to seeing that the auxiliary transformer serves the purpose for which it is intended. Besides technical guidance to ensure proper operation and maintenance of the AT shall be constantly rendered.

18.0 WARRANTY

18.1 The successful tenderer / manufacturer shall warrant that all equipment shall be free from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally acceptable standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

18.2 This warranty shall survive inspection of, payment for and acceptance of the

equipment, but shall expire 24 (Twenty four) months after the delivery at ultimate destination in India, or 18 (Eighteen) months from the date of commissioning and proving test of the equipment at ultimate destination in India, whichever period expires earlier, except in respect of complaints, defects and/or claims notified to the successful tenderer / manufacturer within 3 (Three) months of the expiry of such date. Any approval or acceptance of the Purchaser of the equipment shall not in any way limit the successful tenderer / manufacturer’s liability.

18.3 The successful tenderer / manufacturer’s liability in respect of any complaints, defects

and/or claims shall be limited to the furnishing and installation of replacement parts free of any charges or the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer / manufacturer within 3 (Three) months of their being first discovered during the warranty period of 3 (Three) months from the date of expiry of warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned.

18.4 The successful tenderer / manufacturer shall, if required, replace or repair the

equipment of such portion thereof as is rejected by the Purhaser free of cost at the ultimate destination or at the option of the Purchaser, successful tenderer / manufacturer shall pay to the Purchaser value thereof at the Contract Price or in the absence of such price at a price decided by the Purchaser and such other expenditure and damages as may arise by reason of the breach of the conditions herein specified.

18.5 All replacement and repairs that the Purchaser shall call upon the successful tenderer /

manufacturer to deliver or perform under this warranty shall be delivered and performed by the successful tenderer / manufacture, promptly and satisfactorily and in any case within 2 (Two) months of the date of advice to this effect.

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18.6 If the successful tenderer / manufacturer so desires, the parts that are removed may be

taken over by him or his representative in India for disposal as he deems fit at the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.


repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer / manufacturer, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

18.8 The decision of the Purchaser in regard to the successful tenderer / manufacturer’s

liability and the amount, if any, payable under this warranty shall be final and conclusive.

19.0 TRANSPORTATION OF THE AT.

19.1 The transformer may be transported according to the transport facilities available for the route, viz. by rail, road or sea. All parts, fittings and accessories which are liable to damage during transit shall be removed and packed / crated separately. Detached parts may be packed / crated and sent with AT along with the checklist, so that all the parts are available at the destination with the unit. The packing has to be done properly so that no damage occurs during transit.

19.2 The various components of each AT shall be securely packed in wooden crates and boxes. General packing list, together with weight and overall dimensions of packing cases shall be furnished for each AT indicating the following:

--------------------------------------------------------------------------------------------------- Crate No. Description of Approx. gross Approx. outside Item / component weight in kg. dimensional In the crate --------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------

19.3 As far as possible, the gross weight of the crate / box shall be so kept that it can be conveniently handled by two persons.

19.4 In case of overseas supplies, packing shall be sea-worthy.

19.5 Necessary instructions for handling and storage of all items shall be

included along with the packing lists.

**************

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ANNEXURE-I

For 25 KV/240V, 5 KVA,10 KVA, 25 KVA and 50 KVA Auxiliary Transformer. SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS, SOGP-Part-I (GUARANTEED PARTICULARS AR E TO BE ESTABLISHED BY INSPECTION, ACTUAL TESTS/TEST REPORT S) – Values / Information are to be furnished by each of the tenderers and this will be used for technical evaluation of the tenders.

S.No. Description Specified Value/ Information Value/Information to be furnished by the bidder

1 Name of the manufacturer 2 Standard specification on

which the performance data are based.

3 Type designation. Single Phase oil filled ONAN 4 Continuous rating for

specified cooling, temperature rise and ambient temperature.

i. 5 KVA ii. 10 KVA

iii. 25 KVA iv. 50 KVA

5 Rated temperature rise under normal operating conditions over a maximum ambient of 50°C.

(i) Of oil by thermometer (ii)Of winding by resistance

40°C. 50°C.

6 Rated primary voltage 25 KV (may vary from 19 KV to 27.5 KV)

7 Rated Secondary voltage at all the tap positions on the primary / secondary windings.

240 V

8 Losses 5 KVA

10 KVA

25 KVA

50 KVA

No load Loss, watts 50 60 80 150 Load Loss at 75°C, watts 200 300 500 950 Total Loss, watts 250 360 1300 1100

9 Impedance voltage at rated current for the principal tapping referred to the primary at 75°C.

5%

10 Max. permissible efficiency is to be at

50% of the rated load.

11 Core Type CRGO

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Max. Flux density in any part of lthe core and yoke at principal tap and winding excited with rated voltage / frequency.

1.55 Tesla

12 Max. current density in any of the winding.

2.5 A/mm ²

13 Class of the insulation Class A 14 Insulation withstand strength

of primary winding with 1.2/50 micro-second wave. i) Impulse full wave ii) Impulse chopped wave

190 kV (p) 190 kV (p)

15 Short duration power frequency withstand voltage.

70 kV

16 Tap changer Type Off Circuit No. of plus taps One (+ 5%) No. of minus taps Two (-5%, -10%)

17 Bushings Primary HV end

Primary earthed

Secondary side

Standard specification on which the performance data are based

BIS 2099 - 1973

Impulse withstand voltage (Full wave), KV peak

190 40 40

One minute dry / wet power frequency withstand voltage, KV rms.

70 10 10

Minimum creepage distance, mm

900 90 90

18 Dimensions of assembled transformer

Type of AT 5 kVA

10 kVA

25 kVA

50 kVA

Base to topmost point, mm 1950 1950 1950 1950 Overall breadth, mm 500 500 700 900 Overall length, mm 650 650 850 1000

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ANNEXURE-2 For 25 KV/240V, 5 KVA,10 KVA, 25 KVA and 50 KVA Auxiliary Transformer. SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS, SOGP-Part-II (GUARANTEED PARTICULARS A RE TO BE ESTABLISHED BY INSPECTION, ACTUAL TESTS/TEST REPORT S) S.No. DESCRIPTION UNIT OF

MEASURE MENT

5 Kva 10 kVA 25 kVA 50 kVA

1 Name of the manufacturer 2 Country of origin 3 Reference to specification

based on which performance data is prescribed.

4 Normal rated power KVA 5 Rated primary winding

voltage kV

6 Primary voltage Variation Range

kV

7 Rated secondary winding voltage at all the tap positions.

V

8 Rated frequency Hz 9 Temperature rise over a

maximum ambient temperature of 50°C.

i) Of oil (by thermometer) °C. ii)Of winding (by resistance)

°C.

10 Losses a) No load loss at max. rated primary voltage on principal tapping and at rated frequency.

W

b) Load loss at max. rated current achieved at min. primary voltage of 19 kV and at principal tapping at 75°C.

W

c) Total Loss at rated voltage at principal tapping and at rated frequency.

W

S.No. DESCRIPTION UNIT OF MEASUR

5 Kva 10 kVA 25 kVA 50 kVA

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EMENT 11 Impedance voltage at rated

current for the principal tapping referred to primary at 75°C.

%

12 Reactance voltage at rated current and rated frequency referred to primary at 75°C.

%

13 No load current ata rated voltage and rated frequency rererred to primary.

A

14 a) Full wave lightning impulse withstand voltage for winding

kV peak

b)Separate source short duration power frequency voltage withstand.

i) Neutral terminal of primary winding. ii) Secondary winding.

kV rms.

kV rms.

a) Induced over Voltage withstand of primary winding.

kV rms.

15 Efficiency at unity and 0.8 power factor (At 75 °C) . a) 100% load b) 75% load c) 50% load

% % %

16 Regulatiion at full load at 75°C. a) At unity power factor b) At 0.8 power factor lagging.

% %

17 Core particulars a) Type of core b) Flux density at rataed voltage and 50 Hz (max.) c) Thickness of steel laminations. d) Insulatiion between corelamination (material) e) Type of joint between core limbs and yokes. f) Whether CRGO steel stamping used. g) Conforming to IA

T

mm

232

specification No. h) Core bolt insulation flash over voltage (1 minute )

18 Winding particulars :- a) Type of winding i) Primary ii) Secondary b)Current density in winding : i) Primary winding ii) Secondary c) Size and No. of turns of i) Primary winding wire ii)Secondary winding wire d) Resistance of i) Primary winding at 75°C. ii) Secondary winding at 75°C. e) Conforming to IS Specification No. f) Insulation on winding conductor. g) Type of joints in the winding, if any. h) Minimum flash over distance to earth between

i) Secondary winding

and core. ii)Primary winding and yoke.

A/mm² A/mm²

Ohm.

Ohm.

mm

mm

19 Tap Changer :

a) Type of tap changer

b) No. of plus taps.

c) No. of minus taps.

20 Primary and Secondary bushing :

Primary Secondary

a) Name of the Manufacturers.

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b) Manufacturer’s type designation.

c) Standard specification on which the performance data are based :

d) Whether primary bushings metallised.

e) Rated voltage kV

f) Rated current A

g) Power frequency withstand voltage : i) Wet ii) Dry

kV rms kV rms

h) Dry lightning impulse withstand voltage (1.2/50 us)

kV peak

i) Total creepagae distance in air.

mm

j) Recommended horn gap setting.

mm

k) Weight of assembled bushing.

Kg.

l) Dia of the stem. mm

21 Weight and dimensions. a) Net Weight of core b) Net weight of copper in i) Primary winding ii) Secondary winding c) Net untanking weight of core frame and coils d) Total weight of complete Transformer. e) Insulating oil :-

i) Net weight ii) Total volume

Kg.

Kg. Kg.

Kg.

Kg.

Kg. L

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22. Overall dimensions of the assembled transformer : i) Height ii)Length iii) Breadth

mm mm

mm

23. Untanking height

mm

24 Base mounting details

25. Minimum thickness of Plate of sheet steel enclosure. i) Side ii) Top cover

iii) Bottom

mm mm mm

26. Name of suppliers and conforming IS Specification No. i) Terminal connector ii) Insulating oil iii) ‘O’ ring and gaskets iv) Paints/varnish v) Fasteners : a) Stainless steel b) M.S. hot dip galvanized vi) Press boards. vii) Precompressed press board. viii) Winding wire ix) Core material

27. Other particulars. i) Is the transformer fitted with lifting lugs ? ii) Is the core electrically connected with the tank ? iii) What is the number of joints numbers provided in the

Yes/No

Yes/No

235

a) Primary winding b) Secondary winding iv)Are winding preshrunk ? v) Are arcing horns provided for primary bushing ? vi) Are the porcelain housing of bushings of single piece construction ? vii) Is the shed profile of porcelain housing of the bushing free from under ribs, but has a lip ? viii) Is clause by clause statement of compliance attached ? ix) Are fasteners of 12mm dia-meter and less exposed to atmosphere of stainless steel to grade 0.4 CC 17 Ni. 12 MO2 to IS: 1570 (Part II) ? x) Are the fasteners of more than 12 mm diameter exposed to atmosphere stainless steel or MS hot dip galvanized ? xi) Are all the drawings required as per clause 15.4 attached ? xii) Is warranty as per clause 18.0 ? xiii) Is the list of spares furnished or not ?

Yes/No

Yes/No

Yes/No

Yes/No

Yes/No

Yes/No

Stainless steel / Hot

dip galvanized

Yes / No

Yes/No

Yes/No

236

237

238



SPECIFICATION

FOR

110 KV LIGHTNING ARRESTOR

No. ETI / PSI / 137 (8/89)

239




SPECIFICATION

FOR

110 kV LIGHTNING ARRESTOR

ISSUED BY



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RESEARCH DESIGNS AND STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW – 226 011.

SPECIFICATION NO. ETI / PSI / 137 ( 8 / 89) LIGHTNING ARRESTER – METAL OXIDE GAPLESS TYPE 1.0 SCOPE 1.1 This specification covers the design, manufacture, testing and supply of metal oxide

gapless type lightning arresters intended for outdoor installation for protection of 220 kV / 25 kV or 132 kV / 25 kV or 110 kV / 25 kv or 66 kV / 25 kV single phase, 50 Hz transformers and other equipments of 245 / 132 / 110 / 66 kV class installed in traction sub-stations.

2.0 GOVERNING SPECIFICATION 2.1 As no national or international standard has been finalized on the subject till date, the

lightning arresters alongwith its accessories shall generally conform to the draft circulated by IEC TC 37 (Secretariat) 68 WG – 4, January 1987 on non-linear metal oxide surge arresters without gaps for a.c. system and latest amendment thereof, except where specified otherwise.

2.2 Assistance has been taken from the following standards / documents also while

preparing this specification:

i) IS : 1570 (Pt. V) - 1972 - Stainless and heat resisting steels.

ii) IS : 2099 – 1973 - Bushing for alternating voltages above 1000 volts (1st Rev. ) with Ameniment No. 1

iii) IS : 2629 – 1966 - Recommended practice for hot dip galvanizing of iron & steel.

iv) IS : 2633 – 1972 - Methods of testing uniformity of coating on zinc coated articles (1st Rev.).

v) IS : 3070 (Pt. I) – 1985) - Non-linear resistor type lightning arresters (2nd Rev.).

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vi) IS : 5358 – 1969 - Hot-dip galvanised coating on fasterners.

vii) IS : 5621 – 1980 - Hollow insulators for use in Electrical

equipment (1st Rev.)

viii) IS : 5561 – 1970 - Electric power connectors.

ix) IS : 8704 – 1978 - Methods for artificial pollution test on high voltage insulators for use on a.c. systems.

x) IEC Publication 99 - Lightning arresters. Pt. I ; Non-Linear resistor type arresters for ac systems.

2.3 Equipment meeting any other authoritative standards which ensures an equal of better

quality than the standard mentioned at para 2.1 above shall also be accepted. The salient points of comparison between standard mentioned at para 2.1 above and other standards adopted shall be clearly brought out in the tender and a complete set of such standards (in English language) shall be supplied by the Tenderer alongwith the tender.

2.4. Any deviation from this specification calculated to improve the performance, utility

and efficiency of the equipment proposed by the tenderer, will be given due consideration, provided full particulars with justification thereof are furnished.

3.0 TRACTION POWER SUPPLY SYSTEM. 3.1 General :

The signal phase, 50 Hz power supply for railway traction at 25 kV is obtained from 220 / 132 / 110 / 66 kV three phase grid system through a step down single phase power transformer, the primary winding of which is connected to between two of the phases of three phase effectively earthed transmission line net work of the electricity board. In order to reduce the imbalance on three three phase grid system, the two phases of the three phase transmission line are tapped in a cyclic order, for feeling successive substations. The distance between adjacent substation is normally between 40 to 50 km depending upon the density of the traffic and gradients of the section etc.

3.1.1 One terminal of the 25 kV secondary winding of the traction transformer is connected

to the overhead equipment (OHE) and the other terminal is solidly earthed and connected to the appropriate running returns through the rail (s) and earth to the substation. Where booster transformers and return conductors are used the return current flows through these and partly through the earth in the vicinity of the

242

substation. Approximately midway between two adjacent substations a dead zone known as the “neutral section” is provided to separate the different phases. The power to the OHE on one side of the substation is controlled by an interrupter. In case of a fault on the OHE the feeder circuit breaker isolates it. The incoming 220 / 132/ 110 / 66 kV supply voltage may vary between + 10% and – 12.5% as per I.E. Rule No. 54. A arrangement at a traction substation is at Appendix – A.

3.2 Protection system : 3.2.1 The following relays are provided for the protection of 220 kV side of traction

transformer :

a) Differential protection. b) IDMT over current protection. c) Restricted earth fault protection.

3.3 Insulation levels :

Basic insulation levels of the sub-station equipment on the 220 / 132 / 110 / 66 kV side is as under : ------------------------------------------------------ 220kV 132kV 110kV 66kV ----------------------------------------------------- a) One minute power frequency :

with stand voltage in kV (rms) b) 1.2 / 50 micro second impulse :

withstand voltage in kVp

395

950

275

650

230

550

140

325

3.4 Impedance of traction transformer :

The percentage impedance of 20 MVA, 220 / 25 kV on 132 / 25 kV or 110 / 25 kV or 66 / 25 kV traction transformer at the principal tap position is ( 2 +/ - 0.5 ) %. Only one transformer is in service at a time.

3.5 Short Circuit level : The short circuit level varies between limits indicated in the table below : ------------------------------------------------------------------------------------------------------- Nominal system voltage

Item ---------------------------------------------------------- 220kV 132kV 110kV 66kV ------------------------------------------------------------------------------------------------------- Maximum fault MVA 10,000 5,000 5,000 3,500 -------------------------------------------------------------------------------------------------------

243

4.0 ENVIRONMENTAL CONDITIONS 4.1 The equipments would be in use in moist tropical climate and in areas subjected to

heavy rain-fall and severe lightning in India. The atmospheric conditions are given below :

Max. temperature of air in shade - 45 deg.C

Min. temperature of air in shade - 0 deg . C

Average ambient air temperature 35 deg. C

over a period of 24 hours

Max. relative humidity. - 100 %

Average annual rain fall - 1750 to 6250 mm

Max. no. of thunder – storm days - 85

Max. number of dust storm days per - 35

per annum.

Max. number of rainy days per year. - 120

Basic wind pressure. - 200 Kg / sq.mm.

Max. altitude. - 1000 metres.

4.2 The lightning arrester would also be subjected to chemical pollution from the effluent gases of chemical plants exhaust of steam / diesel locomotives and to saline atmosphere in coastal areas.

4.3 Vibrations :

The lightning arrester being installed on steel structure located by the side of railway tracks, are subject to vibrations with the passage of trains. The amplitude of these vibrations lies in the range of 30 to 150 microns, with instantantaneous peaks going up to 350 microns. These vibrations occur with rapidly varying time periods in the range of 15 to 70 ms.

244

5.0 TECHNICAL SPECIFICATION.

5.1 Rating and other particulars of the lightning arresters.

i) System Three phase a.c. system, solidly earthed.

ii) Nominal system voltage 66kV 110kV 132kV 220kV

(phase to phase)

iii) Permissible variation 66 + 10% 110 + 10% 132 + 10% 220 + 10%

-12.5% - 12.5% - 12.5% -12.5%

iv) Rated frequency 50 Hz 50 Hz 50 Hz 50 Hz

v) Type of lightning Non linear, metal oxide resistor type,

arrester. without gaps.

vi) Line discharge class class 3 class 3 class 3 class 3

vii) Continuous operating 50kV rms 80kV rms 95 kV rms 168 kv rms

voltage capability

(phase to earth).

viii) Maximum discharge 160kVp 250kVp 350kVp 550kVp

voltage at nominal

discharge current.

ix) Nominal discharge 10 kA 10kA 10kA 10kA

current (8 / 20 wave).

x) Power frequency 117kV rms 174kV rms 228kV rms 380kv rms

voltage withstand for

arrester insulator.

xi) Pressure relief class Class – A Class – A Class – A Class – A

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5.2 Construction :

5.2.1 The lightning arrester shall comprise of a number of non-linear resistor blocks, housed inside the porcelain housing. Suitable provision to arrest the relative movement of blocks shall be provided inside the porcelain housing. Lightning arrester shall be of hermetically sealed construction to prevent moisture ingress. The arrester shall have means for relieving internal pressure to prevent explosive shattering of the housing. The pressure relief device shall explosive shattering of the housing. The pressure relief device shall be of the Class – A as per IS : 3070 (Pt. I).

5.2.2 The arresters shall be provided, if necessary with metal guard ring, circular in shape to modify electrostatically the voltage gradient.

5.2.3 The arrester shall have base support suitably designed for mounting on a base plate over a steel supporting structure as per details given in following table :

----------------------------------------------------------------------------------------------------------------

220kV 132kV 110kV 66kV

--------------------------------------------------------------------------------------------------------------

No. of bolts 6 (60 deg. apart)

3 (120 deg. apart)

3 (120 deg. apart)

3 (120 deg. apart)

Size of bolts. M – 12 M – 16 M – 16 M – 16

Pitch Circle diameter. 254 mm 222 mm 222 mm 222 mm

5.2.4 The arrester shall be provided with a terminal connector conforming to IS : 5561. The connector shall be of robust design and as per approved drawing suitable for securing in ACSR –Zebra conductor (28.62 mm diameter) on the live side. Suitable provision on the earth side of the arrester shall be made for connecting two numbers 45 x 6 mm MS flats. An earthing pad with two holes of 13.5 mm dia is preferable. All the hardware required for mounting the lightning arrester, insulating base and surge monitor etc. shall be supplied by the manufacturer.

5.2.5 All ferrous parts used in manufacture of lightning arrester, its assembly and the insulating base shall be hot-dip galvanised. Hardware of diameter less than 12 mm shall be made out of stainless steel conforming to grade 04 Crl7Nil2 Mo2 of IS : 1570 Pt. V and those above or equal to 12 mm shall preferably be of stainless steel or of mild steel hot dip galvanised to RDSO’s specification No. ETI / OHE / 18 (4/84).

246

5.3 Insulating base :

One number insulating base made from best available porcelain shall be supplied by the manufacturer alongwith each arrester. The insulating base shall also have same mounting dimensions as of the lightning arrester mentioned in Clause 5.2.3.

5.4 Surge monitor :

5.4.1 To monitor the healthiness of the lightning arrester, each arrester shall be provided with a surge monitor. Surge monitor shall be designed to record directly the number of surges handled by the lightning arrester on a cyclometric counter, and also indicate the leakage current passing through the lightning arrester on an ammeter continuously. No push button shall be provided in the ammeter circuit for taking the reading of the leakage current. Surge monitors shall be interchangeable and suitable for outdoor service. Suitable terminal connectors and leads etc. shall be supplied alongwith the surge monitor so that these can be installed at a convenient height for ease of visibility. Suitable provision on the earth side of the surge monitor shall be made for connecting two numbers 45 x 6 mm M.S. flats as indicated in Para 5.2.4 above. The design of surge monitor shall be as indicated in Para 5.2.4 above. The design of surge monitor shall be such that in the eventuality of its failure, the lightning arrester base should automatically be connected to the earth system.

5.5 Tenderer shall quote separately for :

i) surge monitor, and

ii) insulating base.

5.6 Name Plate

Each lightning arrester shall be provided with name plate legibly and indelibly marked with the following information :

ontinuous operating voltage.

i) Rated voltage.

ii) Rated frequency.

iii) Nominal discharge current.

iv) Long duration discharge current.

v) Pressure relief class.

vi) Manufacturer’s name or trade-mark, type and identification.

vii) Year of manufacture.

viii) Purchase order number.

5.7 The lightning arrester shall be suitable for outdoor installation where the maximum temperature attainable by an object exposed to sun is 65 deg. C. If required, the manufacturer shall use a porcelain of light colour instead of brown colour to avoid over-heating of the internal components of the arrester, for its satisfactory service.

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6.0 TYPE TESTS

Following type tests shall be carried out in accordance with draft IEC TC 37 WG4 January 87 to prove the general quality of design and its conformity with the specifications.

i) Power frequency reference voltage test.

ii) Residual voltage tests :

a) Steep current impulse residual voltage test,

b) Lightning impulse residual voltage test,

c) Switching impulse residual voltage test.

iii) Long duration current impulse withstand test.

iv) Operating duty tests :

a) Accelerated ageing test,

b) Heat dissipation behaviour of test samples,

c) Switching surge operating duty test,

d) Evaluation of thermal stability in operating duty test.

e) Power frequency voltage versus time characteristics of arrester.

v) Pressure relief test,

vi) Artificial pollution test,

vii) Insulation withstand tests:

a) Lightning impulse voltage test,

b) Power frequency voltage test.

viii) Other miscellaneous tests :

a) Galvanising test on metal parts,

b) Porosity test on porcelain components,

c) Temperature cycle test on porcelain housing,

d) Visual Examination of porcelain housing.

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6.1 Power frequency reference voltage test :

This test shall be carried out at power frequency voltage and at an ambinet temperature of 20 + / - 15 dec. C. The reference voltage shall be measured at defined current at the knee of the current voltage characteristic of the arrester. The crest value of the resistive component of the above defined arrester current shall be in the range of 1 to 20 mA, depending on the nominal discharge current and / or long duration discharge class of the arrester.

In addition, the resistive and capacitive component of the leakage current shall be measured at continuous operating voltage.

6.2 Residual voltage tests

The test shall be made on three samples of complete arrester or arrester sections. The time between discharge must be sufficient to permit the sample to return to approximately ambient temperature. The maximum envelope of the test points shall be drawn in a residual voltage / discharge current curve.

6.2.1 Steep current impulse resiudal voltage test :

A current impulse with 1 micro-second virtual front time shall be used with limites in the adjustments of equipment of + / - 10%. The virtual time to half value on the tail shall be not longer than 20 micro second. One current impulse with peak value equal to the nominal discharge current of the arrester + / - 5% shall be applied to each sample.

6.2.2 Lightning impulse residual voltage test :

A 8/20 current impulse shall be used with limits on the adjustments of equipment such that the measured values are from 7 micro second to 9 micro-second for the virtual front time and from 18 micro-second to 22 micro-second for the time to half value on the tall. Three current impulses shall be applied to each sample with peak values of approximately 0.5, 1.0 and 2.0 times the nominal discharge current of the arrester.

6.2.3 Switching impulse residual voltage test :

Two current impulses of approximately 250 and 1000 Amps (peak) + / - 5% having a virtual front time greater than 30 micro-second but less than 100 micro-second, and a virtual time to half value on the tail of roughly twice the virtual front time shall be applied to each of the three samples.

6.3 Long duration current withstand test :

This test shall be carried out on three new samples of complete arresters, arrester sections or resistor elements, as per clause 59.1.2 of IEC – TC 37 WG 4 January 1987 (Draft). The rated voltage of the test samples shall be at least 3 kV and need not exceed 6 kV. The test shall consist of 18 discharge operations divided into six groups of 3 operations. Intervals between operations shall be 50 to 60 seconds and between groups such that the device cools to near ambient temperature.

249

6.4 Operating duty tests :

Two test shall be made on three samples of complete arresters or arrester sections. The rated voltage of the test samples shall be at least 3 kV and need not exceed 12 kV. The power frequency test voltage to be applied to the test arrester section shall be the voltage of the complete arrester divided by the total number of similar arrester sections.

6.4.1 Accelerated ageing test :

This test procedure is designed to determine the voltage value UC* and UR* used in the operating duty tests (See Annexure – B), which will allow those tests to be carried out on new resistors.

6.4.1.1 Test procedure

Three resistor samples shall be stressed at a voltage equal to the continuous operating voltage of the sample for 1000 house, during which the temperature hall be controlled to keep the surface temperature of the resister at 115 + / - 4 dec. C.

During this accelerated ageing the resistor may be in the surrounding medium used in the arresters. In this case, the procedure shall be carried out on single resistors in a closed chamber where the volume of the chamber is at least twice the volume of the resister and where the density of the medium in the chamber is not less than the density of the medium in the arrester.

If the manufacturer can prove that this procedure carried out in open air is equivalent to the procedure carried out according to the above paragraph, then the procedure can be carried out in open air.

The relevant voltage for this procedure is the corrected maximum continuous operating voltage (UCT) which the resisters must support in the arrester including voltage unbalance effects. This voltage should be determined from the formula :

UCT = UC (1 + 0.03L)

where L is the total length of the arrester in metres, and UC is the continuous operating voltage of the arrester.

The ageing procedure described above shall be carried out on 3 typical samples of resistor elements.

6.4.1.2 Determination of elevated rated and continuous operating voltages.

The three test samples shall be heated to 115 + / - 4 deg. C and the resistor power losses P1CT shall be measured at a voltage UCT, 1 to 2 hours after the voltage application. The resister power losses P2CT shall be measured after 1000 h (-0 + 100 h) of ageing under the same conditions without intermediate de-energising of the test samples. Within the temperature range allowed both measurements shall be made at the same temperature + / - 1 deg. C.

250

If P2CT is greater than P1CT the ratio KCT = P2CT / P1CT, is determined for each sample. In such case, when testing for the operating duty tests the continuous operating voltage UC and the rated voltage UR shall be increated to UC* and UR* respectively, in order to match the increase of power losses due to ageing. If P2CT is equal or less than P1CT, UC and UR should be used without any correction.

UC* and UR* are the highest of three values respectively, determined in the following way :

On three new resistors at ambient temperature the power losses P1C and P1E shall be measured at UC and UR respectively. Thereafter the voltage shall be increased to UC* and UR* so that the corresponding power losses P2C and P2R fulfil the relation:

P2C P2R

------ = KCT : ---------- = KCT

P1C P1R

Where KCT is the biggest of three power loss ratios determined in the ageing test.

The measuring time should be short enough to avoid increased power loss due to heating.

6.4.2 Heat dissipation behaviour of test sample

The test samples shall meet the requirements of Clause 60.3 of IEC – TC – 37 WG – 4 (Draft) January 1987.

6.4.3 Switching surge operating duty test :

6.4.3.1 General

Before the switching surge operating duty test, the lightning impulse residual voltage at nominal discharge current of each three test samples (resister elements) shall be determined at ambient temperature.

Thereafter, the samples shall be exposed to a conditioning test consisting of twenty current impulses with a time interval between the impulses of 50 to 60 seconds and having an 8 / 20 impulse shape and peak value equal to the nominal discharge current of the arrester. This first part of the conditioning may be carried out of the resistor elements in open air at a still air temperature of 20 + / - 15 deg. C. This is followed by two high current impulses of 65 kA, 4/ 10 microsecond impulse shape. The measured peak value of the current impulses shall be within 90% and 110% of the specified peak value. After this conditioning the sections are stored for future use in this switching surge operating duty test (Annexure – B).


At the beginning of the switching surge operating duty test the temperature of the complete section shall be 60 + / - 3 deg. C.

251

The arresters shall be subjected to two long duration current impulses as specified in clause 6.3. The time interval between the impulses shall be 50 to 60 seconds. The conditioning impulses and the long duration current impulses shall be applied with the same polarity.

After the second long duration current impulse the section shall be disconnected from the line and connected to the power frequency source instantaneously, but not later than 100 milliseconds after the impulse. The corrected rated voltage (UR) and the corrected continuous operating voltage (UC) determined from the accelerated against procedure describe shall be applied for a time period of 10 seconds and 30 minutes respectively to prove thermal stability or thermal run-away.

Non-linear metal oxide resistor temperature or resistive component of current or power dissipation shall be monitored during the power frequency voltage application to prove thermal stability or thermal run-away.

Oscillographic records of the voltage and current through the test, sample shall be made at the second long duration current impulse. The energy dissipated by the test sample during the second operation shall be determined from the voltage and current oscillograms and the energy value shall be reported in the type test report. The current and voltage shall be registered continuously during the power frequency voltage, application.

Following the complete test sequence and after the test sample has cooled to near ambient temperature the residual voltage tests which were made at the beginning of the test sequences, shall be repeated. The complete test sequence is illustrated in Annexure – B.

The arrester has passed the test if thermal stability is achieved (Ref : Clause 6.4.4), if the change in residual voltage measured before and after the test is not hanged by more than 5 % and if examined of the test samples after the test removals no evidence of puncture, flashover or crack of the non-linear metal resistors.

6.4.4 Evaluation of thermal stability in the operating duty tests :

The arrester sections subjected to the operating duty tests are considered to be thermally stable and pass the test if the peak of the resistive component of the leakage current or power dissipation or resistor temperature is stabilised or steadily decreases at least during the last part of the 30 minutes of UC* voltage application in the procedures shown in Annexure – B.

6.4.5 Power frequency voltage versus time characteristics of an arrester :

The manufacturer shall furnish the information as required by Clause 60.7 of IEC TC 37 WG – 4 January 1987 (Draft).

6.5 Pressure Relief Test :

This test shall be carried out as per Clause 7.11 of IS 3070 (Pt. I).

6.6 Artificial Pollution Test :

This test is made to show that the temperature rise of the non-linear metal oxide resistor elements of the arrester does not exceed the value on which the operating

252

duty tests are based on which the specified life performance characteristics of the arrester are based.

The salt –fog / solid layer method prescribed in IS : 8704 – 1978 shall be adopted for carrying out this test.

The testing procedure is as follows :

The complete arrester shall be energised at its continuous operating voltage. At different salinities which correspond to non-significant pollution, light pollution, heavy pollution and very heavy pollution (refer IS : 3716 – 1976 – Table – 2), the steady state temperature on the non-linear metal oxide resistors at different points of the arrester shall be measured.

The temperature on the non-linear metal oxide resistance may be measured by thermocouples through holes in the arrester housing, that may to a negligible extent change the conditions of heat dissipation from the resistors. Alternatively, the temperature on the non-linear metal oxide resistors can be registered with temperature sensitive tape built – in on the arrester assembly.

6.7 Insulation withstand test :

This test demonstrate the voltage withstand capability of the external insulation of separately housed arresters.

6.7.1 Fifteen consecutive impulses at the test voltage value shall be applied for each polarity. The arrester shall be considered to have passed the test if no internal disruptive discharges occur and if the number of the external disruptive discharge does not exceed two for each series of 15 impulses.

6.7.2 Power frequency voltage test :

This test shall be carried out as per Clause 7.5 of IS : 3070 (Pt. I)

6.8 Other miscellaneous tests :

6.8.1 Galvanising test on metal parts :

This test shall be carried out as per Clause 7.15 of IS : 3070 (Pt. I).

6.8.2 Porosity test on Porcelain components :


6.8.3 Temperature cycle test on porcelain housing :

The test shall be carried out as per Clause 7.13 of IS 3070 (Pt. I)

6.8.4 Visual examination of porcelain housing :


253

7.0 Before giving the call to RDSO / The Chief Electrical Engineer for inspection and testing of the prototype of the system, the manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the test and nature of the test, venue of the test and the duration of each test and the total number of days required to complete the test at one stretch. Once the schedule is approved, the test shall invariably be done accordingly. However, during the process of type testing or even later, RDSO representative reserves the right to conduct any additional test (s) besides those specified herein on any equipment / sub-system or system so as to test the system to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the manufacturer and RDSO / the Chief Electrical Engineer during the process of testing as regards the type tests and / or the interpretation and acceptability of the type test results, it shall be brought to the notice of the Director General (Traction Installations), RDSO / the Chief Electrical Engineer as the case may be, whose decision shall be final and binding.

8.0 Bulk manufacture of the lightning arrester shall be taken up only after specific written approval is given by the purchaser to the successful tenderer on the basis of the tests conducted on the prototype unit manufactured according to approved design and drawings.

9.0 ACCEPTANCE TESTS

(a) Measurement of power frequency reference voltage.

(b) Lightning impulse residual voltage test at nominal and twice the nominal discharge current..

(c) Partial discharge test: The power frequency voltage applied to the arrester shall be increased up to its rated voltage and after less than 10 seconds decreased to 1.05 times its continuous operating voltage. At that voltage the partial discharge level according to IEC Publ. 270 shall be measured. The measured value shall not exceed 50 pc.

10.0 ROUTINE TESTS

(a) Visual examination.

(b) Measurement of power frequency reference voltage.

(c) Lightning impulse residual voltage test at nominal discharge current of 10 kA.

(d) Measurement of leakage current at continuous operating voltage.

(e) Satisfactory absence from partial discharges and contact noise by any sensitive method

254

11.0 TESTS ON SURGE MONITOR AND INSULATING BASE

While carrying out the prototype tests on the lightning arrester, following tests shall also be done on the surge monitor and insulating base :

11.1 Surge monitor :

(i) Tests for satisfactory operation of surge counter while discharging surges.

(ii) Tests for correctness of leakage current meter before and after the passage of surges.

(iii) Visual examination tests.

The above tests shall also form part of the routine tests.

11.2 Insulating base :

On the prototype insulating base, all tests stipulated vide Clause 6.8 above shall be carried out. During routine tests, only visual examination of the insulating base shall be done.

12. TECHNICAL DATA AND DRAWINGS

12.1 The tenderer shall indicate his compliance or otherwise against each clause and sub-clause of the technical specification. The tenderer shall for this purpose enclose a separate statement, if necessary, indicating the clause reference and compliance or otherwise. Wherever the tenderer deviates from the provisions of the clauses, he shall furnish his detailed remarks.

12.2 The tenderer shall furnish guaranteed performance data, technical and other particulars for the lightning arresters in the proforma attached as Annexure – A.

12.3 The information furnished in Schedule of guaranteed technical, performance, data and other particulars shall be complete in all respects. If there is any entry like “shall be furnished later” or blanks are left against any item, the tender is not likely to be considered as such omissions causes delays in finalising the tender.

12.4 Drawings showing the overall dimensions of the lightning arrester, a cross-sectional view indicating non-linear resistor blocks, retainer arrangement, terminal details, method of connecting high tension on earthing leads and mounting arrangements and evidence in the form of type test reports for the arrester, if available, shall be submitted along with the tender.

12.5 The successful tenderer shall be required to submit the above mentioned detailed dimensioned drawings for approval and shall also furnish six copies of the approved drawings along with copies of transparent reproducible prints, as per Railway Standards. (Standard proforma enclosed as Appendix – III – B).

255

12.6 The successful tender shall also be required to submit, copies of the technical booklets, information manuals, test reports etc.

13.0 TECHNICAL COLLABORATION & INDIGENISATION

Progressive indigenisation of lightning arresters covered by this specification, is contemplated. Design calculations, detailed manufacturing process and all relevant information pertaining to transfer of technical know-how in this regard will be carried out in such a manner between the overseas manufacturer and the Indian Manufacturer as to ensure that the indigenous content of the lightning arrester made in India increases progressively and rapidly without sacrificing quality and reliability. Research Designs & Standards Organisation of the Indian Railways are to be associated at various stages of indigenisation so as to take into account service experience stages of indigenisation so as to take into account service experience while attempting progressive indigenisation.

14.0 WARRANTY

14.1 All lightning arresters supplied against this contract irrespective of origin (imported/indigenous) shall be guaranteed for trouble-free and fully satisfactory performance for a period of 24 months from the date of supply or 18 months from the date of commissioning, whichever is earlier. Details of the warranty clause, the extent of responsibility on the part of the supplier and other relevant aspects will be included in the contract. The tenderer may furnish his detailed terms in this regard in his offer.

14.2 The supplier shall make necessary arrangement for close monitoring of performance of lightning arresters through periodical visits to traction power sub-station/switching posts for observations.

14.3 Technical guidance and assistance for proper operation and maintenance, trouble-shooting investigation and generally all aspects of technical liaison that may be required, shall also be organised by the supplier.

-----------------

This supersedes Specification numbers ETI / PSI / 53 (8 / 79) ETI / PSI / 42 (8/75), ETI / PSI / 18 (8/75), ETI / PSI / 82 (2/87) with Addendum & Corrigenum Slip No. 1 issued in March 87 and ETI / PSI / 89 (4 / 87).

……………………………

256

ANNEXURE – A

SPECIFICATION NO. ETI / PSI / 89 (8 / 89) FOR LIGHTNING ARRESTER.

SCHEDULE OF GUARANTEED PERFORMANCE,

TECHNICAL AND OTHER PARTICULARS.

-------------------------------------------------------------------------------------------------------------

Sl.No. Description Unit of measurement

(1) (2) (3)

----------------------------------------------------------------------------------------------------------------

1. Name of the manufacturer.


3. Standard specification on which performance is based.

4. Manufacturer’s type designation.

5. Rated voltage (rms). kV

6. Continuous operating voltage. kV

7. Watt-loss at continuous operating voltage. Watt / kV

257

8. Watt – loss at rated voltage. Watt / kV

9. Leakage current at C.O.V. mA

10. Leakage current at rated voltage mA

11. Rated frequency. Hz

12. Nominal discharge current (8/20 microsecond wave). kV

13. Residual voltage :

a) at 0.5 times nominal discharge current.

b) at nominal discharge current.

c) at twice the nominal discharge current.

kV (peak)

kV (peak)

kV (peak)

14. Switching impulse residual voltage test with 45 x 90

microsecond current wave of 250 Amp & 1000 Amp.

kVp

15. Steep current impulse residual voltage test with 1

microsecond front time current wave of 10 kA peak.

kVp

16. High current impulse withstand (4/10 microsecond wave). kAp

17. Long duration current impulse rating :

258

a) Peak current.

b) Virtual duration of peak.

c) Line discharge class of arrester.

A Microsecond.

18. Power frequency voltage withstand of arrester insulation

(rms).

a) Dry.

b) Wet.

kV

kV

19. Lightning impulse withstand voltage of arrester. kVp

20. Type of non-linear resistor disc, size (dia, height) and

voltage rating.

Dia mm Height mm kV

21. No. of non-linear discs per section of arrester. No.

22. No. of sections in one arrester. No.

23. Material of retainer use inside lightning arrester bakelite,

ceramic, rubber or other material.

24. Is pressure relief device provided, if so, its class?

259

25. Overall dimensions :

a) Height

b) Diameter.

mm

mm

26. Net weight

27. Mounting base :

i) No. of holes.

ii) Dia of holes.

iii) Pitch circle dia.

No.

mm

mm

28. Are the live and earth ends of arrester suitable

jumper/flats as specified?

29. Are grading rings provided?

30. V – I characteristic curves of the Zn0 element at different

temperatures.

31. Any other technical data, the manufacturer may like to

furnish.

260

ANNEXURE – B

Operating duty test for 10,000 A arresters line discharge Class 3, Clause 6.4.3.

Sw

itch

ing

su

rge

oper

atin

g du

ty t

est

C

ond

itio

nin

g.

Residual voltage measurement at In 8 / 20 1 x In 8 / 20

Time interval not specified.

Conditioning test 20 imp at In 8 / 20

1 Minute interval

20 x In 8 / 20

Time interval not specified.

High current impulse conditioning on sections.

Cooling to ambient temp. High current impulse

conditioning on sections.

2 x 65 kA 4 / 10

Hold for future use.

Cool to or preheat to 60 + 30 C

Long duration current impulse.

50 – 60 seconds.

Long duration current impulse.

261

As short as possible. Not longer than 100 m sec.

Rated voltage, 10 seconds. UR *

Continuous operating voltage 30 minutes. UC *

Cool to ambient 25 + 10 0 C

Residual voltage measurement at In 8 / 20 1 x In 8 / 20

Examination of test samples.

In. = nominal discharge current.

262

Sept. ` 1990 ADDENDUM & CORRIGENDUM SLIP NO. 1 TO SPECIFICATION NO. ETI / PSI / 137 (8 /89) FOR METAL OXIDE GAPLESS TYPE LIGHTNING ARRESTER FOR USE ON 220 kV, 132 kV, 110 kV, 66 kV SIDE OF RAILWAY AC TRACTION SUB-STATIONS.

__________________________________________________________________________ Page – 7, Artificial pollution test

Clause – 6. 0 (vi) :

Delete the clause.

Page – 12, Clause – 9. 0 (d) :

This clause may be re-read as under : - “Lightning impulse residual voltage on the complete arrester or arrester unit at nominal discharge current if possible or at current value in the range of 0.01 to 0.25 times nominal discharge current of the lightning arrester”.

Page – 14, Clause – 10.0 (c) :

This clause may be re-read as under : - “Lightning impulse residual voltage test either on complete arrester, assembled arrester unit on or single or several register elements at a suitable lightning impulse current in the range between 0.01 & 2 times the nominal current at which the residual voltage is measured”.

Page – 14, Clause – 10.0 :

Add “ (f) leakage check by any sensitive method to see the efficacy of the sealing system”. ----------------------------

263

FEBRUARY 1991.

Addendum & Corrigendum Slip No. 2 to Specification. No. ETI / PSI / 137 (8 / 89) for metal oxide gapless type lightning arrester for use on 220 kV, 132 kV, 110 kV, 66 kV side of railway a.c. Traction Sub-stations. Page – 6 Clause 5.6 (viii)

This clause may be re-read as under : “Month & year of manufacture ”. “ (X)

Page – 6 Clause 5.6

Add : manufacturer’s Serial number.”

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DECEMBER 1991 Addendum & Corrigendum slip No. 3 to Specification No. ETI / PSI / 137 (8 / 89) for metal oxide gapless type lightning arrester for use on 220 kV, 132 kV, 110 kV, 66 kV side of Railway a.c. traction Sub-stations. ---------------------------------------------------------------------------------------------------------------- S. No. Clause No. & description. As amended ---------------------------------------------------------------------------------------------------------------- 1. Page 5, Clause 5.2.5 Substitute the following for the existing matter : -

“5.2.5 – all ferrous parts used in manufacture of lightning arrester, its assembly and the insulating bass shall be hot-dip galvanized. All fasteners of diameter upto 12 mm shall be of stainless steel conforming to grade 04 Cr 17 Ni 12 M02 of IS : 1570 Pt. V and those above 12 mm shall preferably be of stainless steel or of mild steel hot dip galvanized to RDSO’s specification. No. ETI / OHE / 18 (4 / 84).”

2. Page No. 13 Clause - 6.8.1

Substitute the following with the existing matter. “6.3.1 – Galvanising tests on metal parts. 3 samples of the cut pieces of galvanized component shall be tested for conformity to RDSO specification. No. ETI / OHE / 13 (4 / 84)”.

3. Page No. 17 Anexure ‘A’ 6. No. 5

Substitute the following with the existing matter : - “ 5

(i) Rated voltage (r.m.s.) - kV (ii) Rated frequency – Hz.”

4. Page. No. 17 Annexure ‘A’ S. No. 11

Substitute the following with the existing matter : - “11

(i) Rated voltage of the Section (metal Oxide disc.) – kV

(ii) Maximum power frequency reference voltage of the section – kV.

(iii) Minimum power frequency reference voltage of the section – kV

Reference current of the lightning arrester – ma”.

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AUGUST 1994

Addendum & Corrigendum slip No. 4 to Specification No. ETI / PSI / 137 (8 / 89) for metal oxide gapless type lightning arrester for use on 220 kV, 132 kV, 110 kV and 66 kV side of Railway AC traction Sub-station. ---------------------------------------------------------------------------------------------------------------- S. No. Clause No. & description. As amended ---------------------------------------------------------------------------------------------------------------- 1. Page 7,

Clause 6.0 (vi) Artificial Pollution Test : - Add this test. This test is to be carried out as per ANSI / IEEE C6 2.11.1987.

2. Page 6, Clause 5.4.2

Add this clause after clause 5.4. “Surge Monitor shall be provided only on 198 kV Lightning Arrestor.”

3. Page 6, Clause 5.3, Para 1, Line 2.

Existing line may be read as under : “Shall be supplied by the manufacturer with 198 kV lightning arrestor only.”

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APRIL 2001 Addendum & Corrigendum slip No. 5 to Specification No. ETI / PSI / 137 (8 / 89) for metal oxide gapless type lightning arrester for use on 220 kV, 132 kV, 110 kV, 66 kV and 22 kV side of Railway AC traction Sub-station. S. No.

Clause No. & description

As amended

1. Clause 1.1 This clause may be re-read as under : This specification covers the design, manufacture, testing and supply of metal oxide gapless type lightning arrester intended for outdoor installation for protection of 220 kV / 25 kV or 132 kV / 25 kV or 110 kV / 25 kV or 66 kV / 25 kV or 22 kV / 25 kV single phase, 50 Hz transformer and other equipment of 245/ 132/ 110 /66 /22 kV class installed in traction substation.

2. Clause 3.1 First line of this clause may be re-read as under : The single phase, 50 Hz power supply for Railway traction at 25kV is obtained from 220/132/110/66 & 22 kV three phase grid system through a step down / step up single phase power transformer. The primary winding of which is connected to between two of the phases of 3φ effectively earthed transmission line network of the electricity Board.

3. Clause 3.1.1 Second last line of this clause may be re-read as under : The incoming 220/132/110/66/22 kV power supply may vary between +10% and –12.5% as per IE rule no. 5.1.

4. Clause 3.3 Add the following in existing table : 22 kV i) one minute power frequency 50 withstand voltage in kV rms. ii) 1.2/50 micro second impulse 125 withstand voltage kVp.

5. Clause 3.4 Impedance of traction transformer. This clause may be re-read as under : The % impedance of 20 MVA, 220 kV / 25 kV or 132 kV / 25 kV or 110 kV / 25 kV or 66 kV / 25 kV or 22 kV / 25 kV traction transformer at the principal tap position is (12 = / - 0.5 ) %. Only one transformer is in service at a time.

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6. Clause 3.5 Add in this clause as under : 22 kV Maximum fault in MVA 1000

7. Clause 5.1 Add the clause as under : i. System ------------------------------ do ---------------------------- ii. Nominal system voltage (phase to phase) 22 kV iii. Permissible variation 22+10% - 12.5% iv. Rated frequency 50 Hz v. Type of lightning arrester ---------- do -------------------------- vi. Line discharge class 2 vii. Continuous operating voltage (phase to earth) 15 kVrms viii. Maximum discharge voltage at nominal 56 kVp

discharge current. ix. Nominal discharge current (8/20 wave) 10 kA x. Power frequency voltage withstand for 50 kVrms

Arrester insulator xi. Pressure relief class. A

8. Clause 5 Add the existing clause as under : No. of bolts (equally spaced) 3(120° apart) 3(120° apart) Size of bolts M-16 M-16 Pitch circle diameter 222 222

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RDSO Specification No. ETI / PSI / 137 / (8/89) Specification for 110 kV Lightning Arrestor. The following amendments are made in addition to the addendum and corrigendum slips issued to the specification. Sl.No. Para No. Amendment 1. Para 3.1 In line 8, substitute 40 km and 50 km with 6.5 km and 25 km

2. Para 3.1.1 In line 8, substitute the word “interrupter” with the

word “Circuit Breaker”. 3. Para 4.1 In line 5, Substitute 0°C with 5°C

In line 12, substitute 200 Kg./sq.mm with 112.5 kg/sq.mm.

4. 5.2.4 In line 5, substitute 45 x 6 mm with 50 x 6 mm 5. 5.4 In line 10, substitute 45 x 6 mm with 50 x 6 mm 6. 5.5 Deleted.

7. 13.0 Deleted. 8. 14.1 In line 3, substitute “24” with “36”

and “18” with “24” Delete the sentences starting with “Details of the warranty clause” ………till ……. “in this regard in his offer”

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SPECIFICATION FOR

LIGHTNING ARRESTER – METAL OXIDE GAPLESS TYPE

No. ETI / PSI / 71 REV.5 (1 / 87)

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Specification No. ETI/PSI/71 Rev. 5 (1/87)

GOVERNMENT OF INDIA MINISTRY OF RAILWAYS,

RESEARCH DESIGNS & STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW – 226011 (INDIA)

SPECIFICATION

FOR

METAL OXIDE GAPLESS TYPE

LIGHTNING ARRESTER

FOR USE ON 25 KV SIDE OF

RAILWAY TRACTION SUBSTATIONS

AND

SWITCHING STATIONS

ISSUED BY


MINISTRY OF RAILWAYS, MANAK NAGAR, LUCKNOW – 226011 .

271


RESEARCH, DESIGN & STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW 226 011

Specification No. ETI/PSI/71 Rev. 5 (1/87)

LIGHTNING ARRESTER – METAL OXIDE GAPLESS TYPE

1.0 SCOPE 1.1 This specification covers the design, manufacture, testing and supply of metal oxide

gapless type lightning arresters intended for outdoor installation at traction substations and switching stations on Indian Railways for protection of various electrical equipments installed at these stations.

GOVERNING SPECIFICATION

As no national or international standard has been finalised on the subject till date, limited assistance has been taken from the following standards / documents while preparing this specification :

i) IS : 3070 (Pt.I) – 1985 Non-linear resistor type lightning arresters

(Rev. II). ii) IEC Publication 99 Lightning arresters. Pt. I; Non-Linear

resistor type arresters for ac systems iii) IS : 2629 – 1966 Recommended practice for hot dip

galvanising of iron & steel. iv) IS : 2633 – 1972 Methods of testing uniformity of coating on zinc coated articles (Rev. I).

v) IS : 5358 – 1969 Hot-dip galvanised coating on fasteners.

vi) IS : 2099 – 1973 Bushing for alternating voltages above 1000 volts (Rev. I) with Amendment No. 1.

vii) IS : 5621 – 1980 Hollow insulators for use in Electrical

equipment (Rev. I).

viii) IS : 5561 – 1970 Electric power connectors. ix) IEC Draft Specn. No. Methods for artificial pollution test on high

TC 37 WG 4 (April 86) voltage insulators for use on a.c. systems. x) IS 1570 (pt-V) – 1972 Schedule for wrought steels, stainless and

heat resisting steels (PT-V). xi) IS 8704 – 1978 Methods for Artificial pollution test on high

voltage insulators for use on ac systems.

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2.2 Any deviation from this specification calculated to improve the performance, utility

and efficiency of the equipment proposed by the tenderer, will be given due consideration, provided full particulars with justification thereof are furnished.

3.0 TRACTION POWER SUPPLY SYSTEM 3.1 General.

Signal phase, 50 Hz power supply for railway traction at 25 kV is obtained from 132 / 25 kV single phase traction power transformer, the primary winding of which is connected between any two phases of 132 kV three phase effectively earthed transmission network of the Electricity Board. Two of the three phase are tapped in a cyclic order, for feeding successive substations to balance the load on the 132 kV system. The spacing between adjacent substation is normally between 50 and 80 km. One terminal of the 25 kV secondary winding of the traction transformer is connected to the overhead equipment (abbreviated as OHE) and the other solidly earthed and connected to the running rails. The load current flows through the OHE to the locomotives and returns through rail and earth to the substation. In the middle of adjacent substations a dead zone known as the “neutral section” is provided to avoid phase-to-phase short. The power to the OHE on one side of the substation is fed by one feeder circuit breaker and each track controlled by an interrupter. In case of fault on the OHE the feeder breaker clears the fault. A typical schematic diagram showing the general feeding arrangement of a traction system, as well as the schematic general arrangement at a traction substation, is given in sketch No. ETI/PSI/702 enclosed at Appendix–II. The incoming 132 kV supply voltage may vary between ± 12.5% as per the standard clause.

3.2 Protection system. 3.2.1 The following relays are provided for the protection of 220 kVside of traction

transformer : d) Differential protection, English Electric Relay, Type DDT-12. e) IDMT over current protection, English Electric Relay, Type CDG-26 on 132

kV side. f) Restricted earth fault protection, English Electric Relay, Type CAG-14 on

132 kV side. g) IDMT over current English Electric Relay, Type CDG-16 on 25 kV side. h) Restricted earth fault English Electric Relay, Type CAG-14 on 25 kV side.

3.2.2 The following relays are provided for the protection of OHE.

a) Differential protection, English Electric Relay, Type YCG-14. b) Instantaneous over current protection, English Electric Relay, Type CAG-

17. c) Wrong-phase coupling protection, English Electric Relay, Type YCG-14.

3.3 Insulation levels.

Basic insulation levels of the equipments provided at the substation are given in Appendix-I.

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3.4 Impedance on 25 kV OHE. 3.4.1 The OHE is made up of a stranded cadmium copper catenary of 65 mm2 and a

grooved copper contact wire of 107 mm2, making up a total of 150 mm2 copper equivalent. The values of loop impedance with earth return for the OHE are as under :

i) Single track OHE - 0.52 / 70º Ohms/km ii) Double track OHE - 0.32 / 70º Ohms/km iii) Single track OHE

with return conductor - 0.75 / 70º Ohms/km iv) Double track OHE with return conductor - 0.45 / 70º Ohms/km 3.5 Impedance of traction transformer.

The resistance and reactance of earth traction power transformer at the traction substation are 0.179 Ohms and 5.49 Ohms respectively. Only the transformer is in service at a time.

3.6 Electrical clearance.

Normally a clearance of 500 mm is provided between any live part at 25 kV and earth.

3.7 Nature of faults on the OHE System 3.7.1 OHE is subjected to frequent earth faults caused by failure of insulation or snapping

of OHE and its touching the rail or earth, or loose wires carried by birds coming in contact with OHE below overline structures, miscreant / activities etc. These faults are cleared by the feeder circuit breaker which operates on any one or both of the following relays depending on the proximity of the fault:

a) Distance protection Mho relay b) Instantaneous over-current relay.

3.7.2 Inadvertent coupling of two phases between adjacent substations at the neutral

section or at intermediate switching stations in case of extended feed, causes short circuit. This is cleared by tripping of one of the feeder breakers at the two ends through a ‘Mho relay’ known as ‘Wrong phase coupling relay’.

Short circuit level.

The 132 kV source impedance may be based on a three phase symmetrical short circuit level between 1000 to 2000 MVA. The level of short circuit on the 25 kV side for a fault in the vicinity of a substation could be around 100 MVA or more.

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3.8 Surges.

From the tests conducted on the over head equipment it has been established that short duration switching surges are generated while carrying out various switching operations. Magnitude of these surges are measured during some tests, is around 120 to 130 kV peak.

4.0 ENVIRONMENTAL CONDITIONS 4.1 The equipments would be in use in moist tropical climate and in areas subjected to

heavy rain-fall and severe lightning in India. The atmospheric conditions are given below:

Max. temperature of air in shade - 45 °C Min. temperature of air in shade - 0 °C Max. temperature attainable by an object exposed to sun. - 65 °C Max. relative humidity - 100 % Average annual rainfall - 1750 to 6250 mm Max. no. of thunder-storm days per annum - 85 Max. number of rainy days per annum - 120 Max. wind pressure - 200 Kg/sq.m2. Max. altitude - 1000 meters.

4.2 They are also subjected to chemical pollution from the effluent gases of chemical plants exhaust of steam / diesel locomotives and to saline atmosphere in coastal areas.

4.3 Vibrations:

The equipment being installed on steel structure located by the side of railway tracks, are subject to vibrations with the passage of trains. The amplitude of these vibrations lies in the range of 30 to 150 microns, with instantaneous peaks going up to 350 microns. These vibrations occur with rapidly varying time periods in the range of 15 to 70 ms.

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5.0 TECHNICAL SPECIFICATION. 5.1 Rating and other particulars.

i) System Single phase a.c. traction.

ii) Nominal system voltage 25 kV (phase to earth)

iii) Possible variation in the 22.5 to 27.5 kV (sometime touching Traction supply voltage 30 kV)

iv) Rated frequency 50 Hz

v) Type of lightning Non linear, metal oxide resistor type,

arrester. without gap. vi) Line discharge class Class 3

vii) Continuous operating 35 kV rms

voltage capability

viii) Max. discharge voltage 125 kVp at nominal discharge current.

ix) Nominal discharge 10 k Amps.

current (8/20 wave)

x) Pressure relief class Class-A

xi) Power frequency 105 kV (rms) voltage withstand for

arrester insulator. 5.2 Construction. 5.2.1 The lightning arrester shall comprise a number of non-linear resistor blocks, housed

inside the porcelain housing. Suitable provision to arrest the relative movement of blocks shall be provided inside the porcelain housing. Lightning arrester shall be of hermetically sealed construction to prevent moisture ingress. The arrester shall have means for relieving internal pressure to prevent explosive shattering of the housing. The pressure relief device shall be of the Class-A as per IS:3070 (Pt.1) – 1974.

5.2.2 The arrester shall have base support suitably designed for mounting on a base plate

over a steel supporting structure with three MS 14 bolts in a triangular formation on a PCD of 274 mm.

5.2.3 The arrester shall be provided with a terminal connector conforming to IS:5561.

The connector shall be of robust design and as per approved drawing suitable for securing an all-aluminium “Spider” conductor on the live side. Suitable provision

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on the earth side of the arrester shall be made for connecting two numbers 45 x 6 mm MS flats. An earthing pad with two holes of 13.5 mm dia. is preferable.

5.2.4 All ferrous parts used in manufacture of lightning arrester or its assembly shall be

hot-dip galvanised. Hardware of diameter less than 12 mm shall be made out of stainless steel conforming to grade 04 Cr17 Ni12 Mo2 of IS:1570 Pt.V – 1972.

5.3 Name Plate.

Each lightning arrester shall be provided with name plate legibly and indelibly marked with the following information: i) Continuous operating voltage. ii) Rated voltage. iii) Rated frequency. iv) Nominal discharge current. v) Long duration discharge class. vi) Pressure relief class. vii) Manufacturer’s name or trademark, type and identification. viii) Year of manufacture. ix) Purchase order number.

5.4 The lightning arrester shall be suitable for outdoor installation where the maximum temperature attainable by an object exposed to sun is 65 °C. If required, the manufacturer shall use a porcelain of light colour instead of brown colour to avoid overheating of the internal components of the arrester, for its satisfactory service.

6.0 TYPE TESTS

Following type tests shall be carried out in accordance with draft IEC TC 37 WG4 April 86 to prove the general quality of design and its conformity with the specifications. i) Power frequency reference voltage test. ii) Residual voltage tests:

a) Steep current impulse residual voltage test b) Lightning impulse residual voltage test c) Switching impulse residual voltage test.

iii) Long duration current impulse withstand test. iv) Operating duty tests:

a) Accelerated ageing test b) Heat dissipation behavior of test samples c) Switching surge operating duty test d) Evaluation of thermal stability in operating duty test e) Power frequency voltage versus time characteristics of arrester.

v) Pressure relief test. vi) Insulation withstand tests:

a) Lightning impulse voltage test b) Power frequency voltage test.

vii) Other miscellaneous tests: a) Galvanising test on metal parts b) Porosity test on porcelain components c) Temperature cycle test on porcelain housing d) Visual examination of porcelain housing.

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6.1 Power frequency reference voltage test:

This test shall be carried out at power frequency voltage and at an ambient temperature of 20 +/- 15 °C. The reference voltage shall be measured at a defined current at the knee of the current – voltage characteristic of the arrester. The crest value of the resistive components of the above defined arrester current shall be in the range of 1 to 20 mA, depending on the nominal discharge current and/or long duration discharge class of the arrester. In addition, the resistive and capacitive component of the leakage current shall be measured at continuous operating voltage.

6.2 Residual voltage tests:

The test shall be made on three samples of complete arrester or arrester sections. The time between discharge must be sufficient to permit the sample to return to approximately ambient temperature. The maximum envelop of the test points shall be drawn in a residual voltage / discharge current curve.

6.2.1 Steep current impulse residual voltage test:

A current impulse with 1 micro-second virtual front time shall be used with limits in the adjustments of equipment of +/- 10%. The virtual time to half value on the tail shall be not longer than 20 micro second. One current impulse with peak value equal to the nominal discharge current of the arrester +/- 5% shall be applied to each sample.

6.2.2 Lightning impulse residual voltage test:

A 8/20 current impulse shall be used with limits on the adjustments of equipment such that the measured values are from 7 micro second to 9 micro second for the virtual front time and from 18 micro second to 22 micro second for the time to half value on the tail. Three current impulses shall be applied to each samples with peak values of approximately 0.5, 1.0 and 2.0 times the nominal discharge current of the arrester.

6.2.3 Switching impulse residual voltage test:

Two current impulses of approximately 250 and 1000 Amps (peak) +/- 5% having a virtual front time greater than 30 micro second but less than 100 micro second, and a virtual time to half value on the tail of roughly twice the virtual front time shall be applied to each of the three samples.

6.3 Long duration current withstand test:

This test shall be carried out on three new samples of complete arresters, arrester sections or resistor elements, as per clause 59.1.2 of IEC-TC 37 WG4 April 1986 (Draft). The rated voltage of the test samples shall be at least 3 kV and need not exceed 6 kV. The test shall consist of 18 discharge operations divided into 6 groups

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of 3 operations. Intervals between operations shall be 50 to 60 seconds and between groups such that the device cools to near ambient temperature.

6.4 Operating duty tests: The test shall be made on three samples of complete arresters or arrester sections. The rated voltage of the test samples shall be at least 3 kV and need not exceed 12 kV. The power frequency test voltage to be applied to the test arrester section shall be the voltage of the complete arrester divided by the total number of similar arrester sections.

6.4.1 Accelerated ageing test: This test procedure is designed to determine the voltage values UC* and U R* used in the operating duty tests (see Annexure-B), which will allow those tests to be carried out on new resistors.


Three resistor samples shall be stressed at a voltage equal to the continuous operating voltage of the sample for 1000 hours, during which the temperature shall be controlled to keep the surface temperature of the resistor at 115 + / - 4 °C. During this accelerated ageing the resistor may be in the surrounding medium used in the arrester. In this case, the procedure shall be carried out on single resistors in a closed chamber where the volume of the chamber is at least twice the volume of the resistor and where the density of the medium in the chamber is not less than the density of the medium in the arrester. If the manufacturer can prove that this procedure carried out in open air is equivalent to the procedure carried out according to the above paragraph, then the procedure can be carried out in open air. The relevant voltage for this procedure is the corrected maximum continuous operating voltage ( UCT ) which the resistors must support in the arrester including voltage unbalance effects. This voltage should be determined from the formula: UCT = UC (1 + 0.03L) Where L is the total length of the arrester in meters, and UC is the continuous operating voltage of the arrester. The ageing procedure described above shall be carried out on 3 typical samples of resistor elements.

6.4.1.2 Determination of elevated, rated and continuous operating voltages - The three test samples shall be heated to 115 +/- 4 °C. and the resistor power losses P1CT shall be measured at a voltage UCT, 1 to 2 hours after the voltage application. The resistor power losses P2CT shall be measured after 1000 h (- 0 + 100 h) of ageing under the same conditions without intermediate de-energising of the test samples. Within the temperature range allowed both measurements shall be made at the same temperature +/- 1 °C. If P2CT is greater than P1CT the ratio KCT = P2CT / P1CT, is determined for each sample. In such case, when testing for the operating duty tests the continuous operating voltage UC and the rated voltage UR shall be increased to UC* And UR*

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respectively, in order to match the increase of power losses due to ageing. If P2CT is equal or less than P1CT, UC and UR should be used without any correction. UC* and UR* are the highest of three values respectively, determined in the following way: On three new resistors at ambient temperature the power losses P1C and P1R shall be measured at UC and UR respectively. Thereafter the voltages shall be increased to UC* and UR* so that the corresponding power losses P2C and P2R fulfill the relation:

P2C P2R

-------- = KCT : ----- = KCT

P1C P1R

where KCT is the biggest of the three power loss ratios determined in the ageing test.

The measuring time should be short enough to avoid increased power loss due to heating.

6.4.2 Heat dissipation behaviour of test sample

The test samples shall meet the requirements of clause 60.3 of IEC-TC-37 WG-4 (Draft) April 1986.

6.4.3 Switching surge operating duty test 6.4.3.1 General

Before the switching surge operating duty test, the lightning impulse residual voltage at nominal discharge current of each three test samples (resistor elements) shall be determined at ambient temperature. Thereafter, the samples shall be exposed to a conditioning test consisting of twenty current impulses with a time interval between the impulses of 50 to 60 seconds and having an 8/20 impulse shape and a peak value equal to the nominal discharge current of the arrester. This first part of the conditioning may be carried out on the resistor elements in open air at a still air temperature of 20 + / - 15 °C. This is followed by two high current impulses of 65 kA, 4/10 micro second impulse shape. The measured peak value of the current impulses shall be within 90 % and 110 % of the specified peak value. After this conditioning the sections are stored for future use in the switching surge operating duty test (Annexure-B).

6.4.3.2 Test procedure At the beginning of the switching surge operating duty test the temperature of the complete section shall be 60 +/- 3 °C. The arresters shall be subjected to two long duration current impulses as specified in clause 6.3. The time interval between the impulses shall be 50 to 60 seconds. The conditioning impulses and the long duration current impulses shall be applied with the same polarity.

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After the second long duration current impulse the section shall be disconnected from the line and connected to the power frequency source instantaneously, but not later than 100 millisecond after the impulse. The corrected rated voltage (UR) and the corrected continuous operating voltage (UC) determined from the accelerated ageing procedure described shall be applied for a time period of 10 seconds and 30 minutes respectively to prove thermal stability or thermal run-away. Non-linear metal oxide resistor temperature or resistive component of current or power dissipation shall be monitored during the power frequency voltage application to prove thermal stability or thermal run-away. Oscillographic records of the voltage across and current through the test sample shall be made at the second long duration current impulse. The energy dissipated by the test sample during the second operation shall be determined from the voltage and current oscillograms and the energy value shall be reported in the type test report. The current and voltage shall be registered continuously during the power frequency voltage, application. Following the complete test sequence and after the test sample has cooled to near ambient temperature, the residual voltage tests which were made at the beginning of the test sequence, shall be repeated. The complete test sequence is illustrated in Annexure-B. The arrester has passed the test if thermal stability is achieved (Ref: Clause 6.4.4), if the change in residual voltage measured before and after the test is not changed by more than 5 % and if examination of the test samples after the test reveals no evidence of puncture, flashover or crack of the non-linear metal oxide resistors.

6.4.4 Evaluation of thermal stability in the operating duty tests

The arrester sections subjected to the operating duty tests are considered to be thermally stable and pass the test if the peak of the resistive component of the leakage current or power dissipation or resistor temperature is stabilised or steadily decreases at least during the last part of the 30 minutes of UC* voltage application in the procedures shown in Annexure-B.

6.4.5 Power frequency voltage versus time characteristics of an arrester

The manufacturer shall furnish the information as required by Clause 60.7 of IEC TC 37 WG-4 April 1986 (Draft).

6.5 Pressure relief test:

This test shall be carried out as per Clause 7.11 of IS: 3070 (Pt. I)

6.6 Insulation withstand test:

This test demonstrates the voltage withstand capability of the external insulation of separately housed arresters.

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6.6.1 Lightning impulse voltage test

Fifteen consecutive impulses at the test voltage value shall be applied for each polarity. The arrester shall be considered to have passed the test if no internal disruptive discharges occur and if the number of external disruptive discharge does not exceed two for each series of 15 impulses.

6.6.2 Power frequency voltage test

This test shall be carried out as per Clause 7.5 of IS: 3070 (Pt. I)

6.7 Other miscellaneous tests: 6.7.1 Galvanising test on metal parts:

This test shall be carried out as per clause 7.15 of IS: 3070 (Pt. I).

6.7.2 Porosity test on porcelain components: This test shall be carried out as per clause 7.14 of IS: 3070 (Pt. I).

6.7.3 Temperature cycle test on porcelain housing This test shall be carried out as per clause 7.13 of IS: 3070 (Pt. I).

6.7.4 Visual examination of porcelain housing

This test shall be carried out as per clause 7.16 of IS: 3070 (Pt. I).

6.8 Artificial Pollution test

This test shall be carried out as per ANSI / IEEEC 62.11.1987.

7.0 ACCEPTANCE TESTS a) Measurement of power frequency reference voltage b) Lightning impulse residual voltage test at nominal and twice the nominal discharge

current

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c) Partial discharge test:

The power frequency voltage applied to the arrester shall be increased upto its rated voltage and after less than 10 seconds decreased to 1.05 times its continuous operating voltage. At that voltage the partial discharge level according to IEC Publ. 270 shall be measured. The measured value shall not exceed 50 pC.

8.0 ROUTINE TESTS (a) Visual examination. (b) Measurement of power frequency reference voltage (c) Lightning impulse residual voltage test at nominal discharge current (d) Measurement of leakage current at continuous operating voltage (e) Satisfactory absence from partial discharges and contact noise by any sensitive

method

9.0 TECHNICAL DATA AND DRAWINGS 9.1 The tenderer shall indicate his compliance or otherwise against each clause and sub-

clause of the technical specification. The tenderer shall for this purpose enclose a separate statement, if necessary, indicating the clause reference and compliance or otherwise. Wherever the tenderer deviates from the provisions of the clauses, he shall furnish his detailed remarks.

9.2 The tenderer shall furnish guaranteed performance data, technical and other

particulars for the lightning arresters in the pro forma attached as Annexure-A. 9.3 Drawings showing the overall dimensions of the lightning arrester, a cross-sectional

view indicating non-linear resistor blocks, retainer arrangement, terminal details, method of connecting high tension and earthing leads and mounting arrangements and evidence in the form of type test reports for the arrester, if available, shall be submitted along with the tender.

9.4 The successful tenderer shall be required to submit the above mentioned detailed

dimensioned drawings for approval and shall also furnish six copies of the approved drawings along with copies of transparent reproducible prints, as per Railway Standards. (Standard pro forma enclosed as Appendix – III).

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9.5 The successful tenderer shall also be required to submit copies of the technical

booklets, information manuals, test reports, etc. 10.0 TECHNICAL COLLABORATION AND INDIGENISATION

Progressive indigenisation of lightning arresters covered by this specification, is contemplated. Design calculations, detailed manufacturing process and all relevant information pertaining to transfer of technical know-how in this regard will be carried out in such a manner between the overseas manufacturer and the Indian manufacturer as to ensure that the indigenous content of the lightning arrester made in India increases progressively and rapidly without sacrificing quality and reliability. Research, Designs and Standards Organisation of the Indian Railways are to be associated at various stages of indigenisation so as to take into account service experience while attempting progressive indigenisation. The information exchanged between the overseas manufacturer and the Indian manufacturer is not ordinarily required to be passed on to the Indian Railways. However, the authorised representative of he Indian Railways shall have access to the above information at the manufacturer’s works overseas or the manufacturer’s works / Design office in India, whenever it becomes necessary for the purpose of inspection and acceptance of the product at the manufacturer’s works or for the purpose of analysis investigation for overcoming difficulties and problems and for improving the performance reliability in service.

11.0 WARRANTY 11.1 All lightning arresters supplied against this contract irrespective of their origin

(imported / indigenous) shall be guaranteed for trouble-free and fully satisfactorily performance for a period of 24 months from the date of supply or 18 months from the date of commissioning, whichever is earlier. Details of the warranty clause, the extent of responsibility on the part of the supplier and other relevant aspects will be included in the contract. The tenderer may furnish his detailed terms in this regard in his offer.

11.2 The supplier shall make necessary arrangements for close monitoring of

performance of lightning arresters through periodical visits to traction power substations / switching posts for observations.

11.3 Technical guidance and assistance for proper operation and maintenance, trouble

shooting investigation and generally all aspects of technical liaison that may be required, shall also be organised by the supplier.

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APPENDIX – I Various electrical equipments provided at traction substations and switching stations and their insulation levels: ------------------------------------------------------------------------------------------------------------

Equipment Standard B.I.L Lightning Power frequency impulse withstand voltage withstand for one minute ------------------------------------------------------------------------------------------------------------ 1. Traction power for secondary

transformer side 250 kVp 95 kV rms

2. i) 25 kV circuit breaker 250 kVp 95 kV rms

ii) 25 kV current transformer 250 kVp 95 kV rms

iii) 25 kV potential transformer protection type 250 kVp 95 kV rms

iv) 25 kV booster transformer 250 kVp 95 kV rms v) 25 kV bus bars 240 kVp --

vi) 25 kV shunt capacitor 250 kVp 105 kV rms

3. i) 25 kV interrupters 190 kVp 80 kV rms

ii) 25 kV potential transformer line indication type 190 kVp 80 kV rms

iii) 10 kVA/ 25kV/ 230 V LT

supply transformer 190 kVp 80 kV rms iv) 25 kV single pole isolator 190 kVp 95 kV rms

285

ANNEXURE – A

SPECIFICATION NO. ETI/PSI/71 REV. I (1/87) FOR LIGHTNING ARRESTERS

SCHEDULE OF GUARANTEED PERFORMANCE

TECHNICAL AND OTHER PARTICULARS

S. No description Unit of measurement


2. Country of origin

3. Standard specification on which performance is based


5. Rated voltage (rms) kV

6. Continuous operating voltage

kV

7. Watt-loss at continuous operating voltages

Watt / kV

8. Watt-loss at rated voltages

Watt / kV

9. Leakage current at COV

mA

10. Leakage current at rated voltage

mA

11. Rated frequency Hz. 12. Nominal discharge current (8/20 wave)

kA

13. Residual voltage a) at 0.5 times nominal discharge current b) at nominal discharge current c) at twice the nominal discharge current

kV (peak) kV (peak) kV (peak)

14. Switching impulse residual voltage test with 40x90 micro second current wave of 250 amp and 1000 amp

kVp

15. Steep current impulse residual voltage test with 1.0 micro second front time and current wave of 10 kA peak

kVp

16. High current impulse withstand (4/10 wave) kAp 17. Long duration current impulse rating:

a) peak current b) virtual duration of peak line discharge class of the arrester

A micro-second

286

18. Power frequency voltage withstand of arrester insulation (rms): a) Dry Wet

kV kV

19. Lightning impulse withstand voltage of arrester insulation

kVp

20. Type of non-linear resistor disc, size (dia, height) and voltage rating

kV

21. No. of non-linear discs per section of arrester.

No

22. No. of sections in one arrester. No

23. Material of retainer used inside lightning arrester bakelite, ceramic, rubber or other material.

24. Is pressure relief device provided, if so, its class.

25. Overall dimensions : a) Height b) Diameter

mm mm

26. Net weight Kg

27. Mounting base : i) No. of holes ii) Dis. of holes iii) Pitch circle dia.

No. mm mm

28. Are the live and earth ends of the arrester suitable for jumper / flats as specified?

29. Are grading rings provided?

30. V-I characteristic curves of the ZnO element at different temperature.

31. Any other technical data, the manufacturer may like to furnish.

287

ANNEXURE – B Operating duty test for 10,000 A arresters line discharge Class 3, Clause 6.4.3.

Sw

itchi

ng s

urg

e op

erat

ing

dut

y te

st.

Co

ndi

tion

ing

.

Residual voltage measurement at In 8/20

1 x In 8/20

Time interval not specified

Conditioning test 20 imp. at In 8/20 1 Minute interval.

20 x In 8/20

Time interval not specified

High current impulse conditioning on sections. Cooling to ambient temperature. High current impulse conditioning on sections.

2 x 65 kA 4/10

Hold for future use.

Cool to or preheat to 60 ± 3 °C.

Long duration current impulse

50 – 60 seconds.

Long duration current impulse

As short as possible. Not longer than 100 msec.

Rated voltage, 10 seconds.

UR*

Continuous operating voltage 30 minutes

UC*

Cool to ambient 25 ± 10 °C.

Residual voltage measurement at In 8/20

1 x In 8/20

Examination of test samples.

In = nominal discharge current.

288

Addendum & Corrigendum Slip No. 1 to Specification No. ETI/PSI/71 Rev. 5 (1/87) for

Metal oxide gapless type lightning arrester for use on 25 kV side of Railway Traction Substations and Switching Stations.

Page No. 7 Add “ (viii) Artificial Pollution Test”. Clause 6 Page No. 12 Add Clause 6.8 as under : Clause 6 “ 6.8 Artificial Pollution Test :

This test is made to show that the temperature rise of the non-linear metal oxide resister elements of the arrester does not exceed the value on which the operating duty tests are based and on which the specified life performance characteristics of the arrester are based. The salt-fog / solid layer method prescribed in IS : 6704 – 1978 shall be adopted for carrying out this test. The testing procedure is as follows : The complete arrester shall be energised at its continuous operating voltage. At different salinities which correspond to non-significant pollution, light pollution, heavy pollution and very heavy pollution (refer IS : 3716 – 1976 Table-2), the steady state temperature on the non-linear metal oxide resistors at different points of the arrester shall be measured. The temperature on the non-linear metal oxide resisters may be measured by thermocouples through holes in the arrester housing, that to a negligible extent changes the conditions of heat dissipation from the resistors. Alternatively, the temperature on the non-linear metal oxide resistors can be registered with temperature sensitive tape built-in on the arrester assembly. ”

289

September 1990 Addendum & Corrigendum Slip No. 2 to

Specification No. ETI/PSI/71 Rev. 5 (1/87) for Metal oxide gapless type lightning arrester for use on

25 kV side of Railway Traction Substations and Switching Stations. Page No. 12 Delete the Clause. Clause 6.7.1 Page No. 12 Artificial Pollution test . Clause 6.8 Delete the clause. Page No. 13 This clause may be re-read as under :- Clause 7.0 (b) “Lightning impulse residual voltage test on the complete

arrester or arrester unit at nominal discharge current if possible or at current value in the range of 0.01 to 0.25 times nominal discharge current of the lightning arrester”.

Page No. 13 This clause may be re-read as under :- Clause 8.0 (e) “Lightning impulse residual voltage test either on complete

arrester, assembled arrester unit on or single or several register elements at a suitable lightning impulse current in the range between 0.01 & 2 times the nominal current at which the residual voltage is measured”.

Page No. 13 Add “(f) leakage check by any sensitive method to see the

efficiency of the sealing system”. --------------------------------------------------------------------------------------------------------------

290



Page No. 6 This Clause may be re-read as under: Clause 5.3 (viii) “Month & year of Manufacture”.

Page No. 6 Add “ (x) Manufacturer’s Serial Number”

Clause 5.3 ----------------------------------------------------------------------------------------------------------------------

291

December 1991



Sl.No. Clause No. & Description As amended 1. Page No. 6 Substitute the following for the existing

Clause 5.2.4 matter : “5.2.4 – All ferrous parts used in manufacture of lightning arrester, its assembly and the insulating base shall be hot-dip galvanised. All fasteners of diameter upto 12 mm shall be of stainless steel conforming to grade 04 Cr17 Ni12 Mo2 of IS : 1570 Pt. V and those above 12 mm shall preferably be of stainless steel or of mild steel hot dip galvanised to RDSO’s specification No. ETI/OHE/18 (4/84)”

2. Page No. 12 Substitute the following for the existing

Clause 6.7.1 matter : “6.7.1 – Galvanised tests on metal parts. 3 samples of the cut pieces of galvanised component shall be tested for conformity to RDSO Specification No. ETI/OHE/13 (14/84)”

3. Appendix - 1 Substitute the following with the existing

S. No. 3 (iv) matter :

“ iv) 25 kV 250 kVp 95 kV Single (rms)”Pole Isolator 4. Annexure ‘A’ Substitute the existing matter with the

S. No. 5 following:

“ 5 (i) rated voltage (r.m.s) – kV (ii) rated frequency – Hz ”

292

5. Annexure ‘A’ Substitute the existing matter with the

S. No. 11 following:

“ 11 (i) Rated voltage of the section (Metal Oxide disc) – kV

(ii) Maximum power frequency reference voltage of the section – kV (iii) Minimum power frequency reference voltage of the section – kV (iv) Reference current of the lightning arrester - mA”

293

August 1994.

Addendum & Corrigendum Slip No. 5 to the Specification No. ETI/PSI/71 Rev.5 (1/87) for


Sr.No. Clause No. and Description As amended ------------------------------------------------------------------------------------------------------ 1. Page 12 Add clause 6.8 as under :- Clause 6.0 Artificial Pollution Test:

This test is to carried out as per ANSI / IEEEC, 62.11.1987

--------------------------------------------------------------------------------------------------------------------------------

294

RDSO Specification No.ETI/PSI/71 Rev.5(1/87) for Lightning Arrestor for use on 25 kV side.

The following amendments are made in addition to the addendum and corrigendum slips issued to the specification.

S.No. Para No. Amendment 1. Para 3.1 In line 2, add “110/25 kV, 22/25 kV” after 132/25 kV” In line 3, 6 & 23 add, “110 kV, 22 kV” after 132 kV” In line 7, substitute “50 and 80 kms” with 6.5 and 25 kms. In line 14, substitute “interrupter” with “circuit breaker”

In line 18, add “110 kV, 22 kV” after “132 kV” and delete the words “between ± 12.5%” as per the standard clause and add “ as per I.E. rules”

2. Para 3.2.1 (a) In line 1, substitute “220 kV” with the word “primary” (b) Substitute “132 kV side” with primary side” (c) Substitute “132 kV side” with primary side” 3. Para 3.4.1 In line 1, add the word “generally” before the word “made up of” At the end of the para add the following :

However, in the section where the TSS is being set up, the OHE configuration is copper catenary of 193 sqmm and g roved copper contact wire of 242 sqmm. Based on this, the loop impedance values may have to be calculated.

295

4. Para 3.5 Modify the para as below Impedance voltage of traction transformer. The percentage impedance voltage of traction transformer is 12± 5% Only one transformer is in service at a time. 5. Para 3.7.1 (a) Delete the word “Mho” in line 1 before the word “relay” 6. Para 3.7.2 Delete the word “Mho” in line 4 before the word “relay”

7. Para 3.8 Modify the para as below The normal short circuit apparent power for various system

voltagae for primary side of traction transformer is as under : Highest system Short circuit Voltage kV apparent power MVA 24 1000

72.5 3500 123 6000 145 10000 245 20000 The level of fshort circuit on the 25 kV side for a fault in the vicinity of a substation could be around 100 MVA or more.

296

8. 4.1 In line 5, substitute “0ºC” with “5ºC” In line 1.1, substitute “200 kg/m2 with “112.5 kg/m2 9. 5.2.3 In line 4, substitute “45 x 6” mm with “50 x 6” mm 10. 10.0 ` Deleted 11. 11.1 In line 3, substitute “24” with “36” In line 3, substitute “18with “24” Delete the sentence starting with the word “Details of the

warranty clause” …….. till the word “in his offer” 12. Appendix-1 3(i) Delete

297



FOR

CURRENT TRANSFORMERS,

i. 220 kV, 200 – 100 / 5 A;

ii. 132 kV, 400 – 200 / 5 A;

iii. 110 kV, 400 – 200 / 5 A;

iv. 66 kV, 800 – 400 / 5 A;

FOR RAILWAY AC TRACTION SUBSTATION

No. ETI / PSI / 117 (7 / 88)

298

SPECIFICATION NO. ETI / PSI / 117 ( 7 / 88 )




FOR

CURRENT TRANSFORMERS,

i. 220 kV, 200 – 100 / 5 A;

ii. 132 kV, 400 – 200 / 5 A;

iii. 110 kV, 400 – 200 / 5 A;

iv. 66 kV, 800 – 400 / 5 A;

FOR

RAILWAY AC TRACTION SUBSTATION

JULY 1988

ISSUED BY


MANAK NAGAR, LUCKNOW – 226 011.

GOVERNMENT OF INDIA : MINISTRY OF RAILWAYS RESEARCH DESIGNS & STANDARDS ORGANISATION

299

SPECIFICATION NO. ETI / PSI / 117 / (7 / 88)

CURRENT TRANSFORMER, 220 kV or 132 kV or 110 kV or 66 kV 1. SCOPE 1.1 This specification applies to outdoor electrically exposed type current transformer

for a nominal system voltage of 220 kV or 132 kV or 110 kV or 66 kV for use in unattended Railway traction sub-station in any part of India together with associated electrical/electronics measuring / indicating instrument and protective devices. It supersedes specification no. ETI / PSI / 102 (8 / 87), ETI / PSI / 40 (8 / 83), ETI / PSI / 22 (9 / 82) and ETI / PSI / 55 (9 / 79).

1.2 The current transformer shall be complete with all parts, fittings and accessories

including mounting frame work of steel, necessary for its efficient operation. All such parts, fittings and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not. The current specification, whether specifically mentioned or not. The current transformer shall be of proven design.

2. GOVERNING SPELCIFICATION 2.1 Assistance has been taken from the following specifications code of practices (latest

version) in preparation of this specification : - 1) IS : 5 – 1978

(3rd Revision) Colour for ready mixed paints and enamels.

2) IEC – 185 – 1966 Current transformer.

3) IS : 335 – 1983 Specification for new insulting oil.

4) IS : 1271 – 1958 Classification of insulating material for electrical machinery and apparatus in relation to their thermal stability in service.

5) IS : 1570 (Pt. V) Specification of bolt, nut and spring washer.

6) IS : 1576 – 1967 Solid press – board for electrical purposes.

7) IS : 2074 – 1979 Ready mixed paint, air drying red oxide zinc chrome priming.

8) IS : 2099 – 1985 Bushing for alternating voltages above 1000V.

9) IS : 2705 – 1981 Specification for current transformers : - Part – I - General requirement, Part - II - Measuring current transformer,

300

Part - III - Protective current transformer.

10) IS : 2932 – 1974 Enamel synthetic interior (a) under coating (b) finishing

11) IS : 3024 – 1965 Electric steel sheet (oriented with amendment No. 1 & 2)

12) IS : 4253 (Pt. II) – 1983 Application guide for current transformer.

13) IS : 4253 (Pt. II) – 1980 Cork & rubber.

14) IS : 5561 – 1970 Electrical power connector.

15) IS : 11322 – 1955 Method for partial discharge measurement in instrument transformer.

16) RDSO’s Specn No. ETI / OHE / 18 (4 / 84) with correction slip No. 3 (9/87).

Steel & stainless steel fastners.

17) RDSO’s Specn. No. ETI / PSI / 70 (11 / 84)

Specification for hollow porcelain insulator and bushings.

2.2 Any deviation from this specification proposed by the tenderer calculated to

improve upon the performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of the deviation with justification thereof are furnished. In such a case, the tenderer shall quote according to this specification and deviations, if any, proposed by him shall be quoted as an alternative / alternatives. In case of any contradiction between the provisions of the Indian Standards Specification / Recommendations of IEC and this specification the latter shall prevail.

3. SERVICE CONDITIONS 3.1 Environmental conditions:

i) Maximum temperature of air in the shed 45 degree C

ii) Minimum temperature of air in the shed 0 degree C iii) Maximum relative humidity 100 percent iv) Maximum basic wind pressure 200 kg / sqm.

v) Maximum number of thunderstorm

days per annum

85 days

vi) Maximum number of dust storm days per annum 35 days

vii) Annual rainfall Ranging from 1750 mm to 6250 mm

viii) Altitude Not exceeding 1000 m

301

3.2 The current transformer would be subjected to vibrations on account of trains

running on nearby railway tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 to 70 ms lies in the range of 30 to 150 microns at present with the instantaneous peak going upto 350 microns.

4. TRACTION POWER SUPPLY SYSTEM 4.1 General Scheme : The single phase, 50 Hz power supply for railway traction at

25 kV is obtained from 220 / 132 / 110 / 66 kV three phase grid system through a step down single phase power transformer, the primary winding of which is connected to two of the phases of the three-phase effectively earthed transmission line net-work of the State Electricity Board. In order to reduce the imbalance on the three-phase grid system, the two phases of the three-phase transmission line are tapped in a cyclic order for feeding the successive substations. The distance between adjacent sub-stations is normally 40 km and 80 km depending upon the density of the traffic, gradients in the section, etc.,

4.1.1 One terminal of the 25 kV secondary winding of the traction transformer is

connected to the overhead equipment (OHE) and the other terminal is solidly earthed and connected to the appropriate running rails. The load current flows through the OHE to the locomotives and returns through the rail (s) and earth to the substation. Where booster transformers and return conductors are used the return current flows through these and partly through the earth in the vicinity of the substation. Approximately midway between two adjacent sub-stations a dead zone known as the “neutral section” or “Phase break” is provided to separate the different phases. The power to the OHE on one side of the substation is controlled by a feeder circuit breaker while that for each track is controlled by an interruptor. In case of a fault on the OHE, the feeder circuit breaker isolates it. The incoming 220 / 132 / 110 / 66 kV supply voltage may vary between + 10 % and - 12. 5 % as per I. E. Rule No. 54. A schematic diagram No. ETI / PSI / 707 MOD ‘A’ showing the general arrangement at a traction sub-station is at Appendix – A.

4.2 The current transformer shall be on the primary side of the single phase a power

transformer for use with the following electrical / electronic measuring / indicating instruments / meters and protective devices / relays : -

a) Instantaneous over current relay, b) Inverse Definite Minimum time lag over current relay, c) Restricted earth fault – relay,

A panel / Digital type indicating Ammeters will also be connected to these current transformers.

4.3 Operation of any of the protective devices / relays which serve as the back up

protective system for that on the 25 kV side of the traction power transformer shall trip the circuit breaker on the primary side of the transformer. A schematic diagram showing the protection scheme is at Appendix – B.

302

5. RATING AND OTHER PARTICULARS

5.1 The rating and other particulars of the current transformer shall be as follows : -

i) Type Single phase, oil fill natural air cooled. ii) No. of windings Primary - two

Secondary - two iii) System voltage ---------------------------------------------------------------------------------------------------

a. Nominal system voltage, kV 220 132 110 66

b. Highest system voltage, kV 245 145 123 72

iv) Rated primary / secondary currents :


b. Highest system voltage, kV 245 145 123 72

c. Primary current, Amp 200- 100

400- 200

400- 200

800- 400

d. Secondary current, Amps 5 5 5 5

v) Rated frequency …… 50 Hz + 3% vi) Class of insulation …… A

vii) Rated burden ……. 30 VA

viii) Accuracy class ……. 5P to IS : 2705 – 1981 (Part III)

ix) Accuracy limit factor ……. 15

x) Rated short-time current :

Nominal system voltage, kV

Transformation ratio

Short-time current rating (thermal) for one second, kA

Short-time current rating (Dynamic), kA

220 200 – 100 / 5 31.5 78.75

303

132 400 – 200 / 5 25.0 62.5 110 400 – 200 / 5 31.5 78.75 66 800 – 400 / 5 31.5 78.75

xi) Rated insulation level :


b. Rated one minute power frequency withstand voltage, kV (rms)

460 275 230 140

c. Impulse withstand voltage (1.2 / 50 micro. Sec. Wave shape), kV (peak)

1050 650 550 325

xii) Terminal Bushing :


b. Rated current, Amps. 800 800 800 800

c. Minimum creepage distance, mm 6125 3625 2075 1813

xiii) Temperature rise see clause 10.1.2 xiv) Rated overload ……. 150 % of full load for 15 minutes.

xv) Knee-point voltage :

C. T. Ratio Knee – point voltage (Minimum) -------------------------------------------------------------------- Nominal system voltage, kV -------------------------------------------------------------------- 220 132 110 66

--------------------------------------------------------------------------------------------- 100 / 5A 2560 V ----- ---- ------

200 / 5A 1280 V 1070 V 1280 V ------

400 / 5A ---- 535 V 640 V 750 V

800 / 5 A ------ ------ ------ 375 V

6. TYPE & GENERAL CONSTRUCTION. 6.1 The current transformer shall be suitable for mounting on steel structures embedded

in concrete foundations close to the circuit breakers.

304

6.2 The current transformer shall be of sealed type either filled with inert gas or provided with metallic bellows above the cooling and insulating oil. In case of inert gas filling, a pressure relief device shall be provided.

6.3 The core shall be built – up of high permeability cold rolled grain oriented (CRGO)

silicon steel laminations conforming to IS : 3024, the laminations being coated on both sides with suitable insulation capable of withstanding stress relief annealing.

6.4 Class ‘A’ insulation immersed in oil shall be used. The current transformer shall be

supplied complete with insulating oil conforming to IS : 335 required for first filling.

6.5 The current transformer shall have a single core with wound primary. It shall be

possible to change the transformation ratio by series or parallel connecting the primary windings by means of suitable links externally. The wire used for secondary winding shall be procured from the reputed manufacturers only having a certification mark licence from the Bureau of Indian Standards for the purpose. Super enamelled wire shall preferably be used for secondary winding. Copper conductor shall be used for all windings.

6.5.1 Normally no joints in the winding shall be allowed. Joints if unavoidable shall be

brazed with high silver alloy grade Ba Cu Ag 6 of IS : 2927 – 1975 or butt – welded.

6.6 The secondary terminals of the current transformer shall be housed in a weather-

proof terminal box of mild steel of thickness not less than 1.6 mm. The connection / disconnection of external cable to / from the terminals shall be easy and convenient. The cables shall be of 4 sq. mm. Sections 2 core VC insulated & PVC sheathed and their entry into the terminal box shall be through proper cable glands fitted on the bottom of the terminal box. The cable glands shall be supplied with the current transformer.

6.6.1 Facilities for short-circuiting the secondary terminal shall be provided within the

terminal box. The current transformer shall be provided with a standard 10A test winding.

6.7 All the bolted mechanical and electrical connections in the current transformer shall

be tightened properly to prevent loosening in service due to vibrations. 7. BUSHING AND TERMINAL ARRANGEMENT. 7.1 Outdoor type bushing shall conform to IS : 5621. The basic insulation level shall

have the appropriate value as given in Clause 5.1 (xi) of this specification. The porcelain housing shall be capable of withstanding all electrical and mechanical stresses that might be proceeded during the operation of the current transformer under normal and short-circuit conditions.

7.2 The profile of porcelain shed shall be simple and free from ribs on the underside so

as to avoid accumulation of dust and pollutants and permit easy cleaning.

305

7.3 Porcelain housing / support insulator used shall have creepage distance as given in Clause 5.1 (xii) – c.

7.4 The bushing / housing terminals shall be provided with rigid type connectors as per

Research Designs & Standards Organisation (RDSO) drawing No. ETI / PSI / 110**** suitable for connection to ‘ZEBRA’ 28.62 mm ACSR conductor. The connector shall conform to IS : 5561 and its design shall be such so as to be connected to the equipment terminal pad with a minimum of four 12 mm dia bolts, nuts and lock nuts which shall all be of stainless steel conforming to nuts which shall all be of stainless steel conforming to IS : 1670 (Pt. V) Grade 04 Cr 17 Ni 12 Mo2. Each of these bolts shall also have flat washer and spring washer.

7.5 The connectors and porcelain housing shall be procured only from approved

manufacturers. 7.6 For equipment earthing, the steel supporting frame shall be provided with two

earthing terminals of adequate capacity to carry the rated short-circuit current safely. The earthing terminal shall be connected to 50 mm x 8 mm M.S. flat. The earthing terminal shall be provided with 17.5 + 0.5 / - 0.0mm dia. Hole for fixing the earthing flat.

8. PARTS, FITTINGS & ACCESSORIES. 8.1 Apart from the parts, fittings & accessories specifically detailed in the foregoing

clauses, the following shall be supplied with each current transformers :-

(i) Rating plate with diagram of connections and terminal markings. (ii) Weather-proof terminal box. (iii) Lifting lugs.

(iv) Pressure release device.

(v) Nitrogen gas filling valve & oil filling port.

(vi) Oil level gauge of prismatic glass.

(vii) Adjustable arcing horns.

(viii) Cable gland (brass nickel plated).

9. PAINTING 9.1 All the steel surfaces which are in contact with insulating oil shall be painted with

heat resistant oil insoluble insulating varnish. All steel surfaces exposed to weather shall be given one primer coat of zinc chromate and two coats of grey paint to shade No. 631 of IS : 5. One coat of additional paint shall be given at site by the manufacturer.

9.2 FASTENERS.

306

All fasteners of 12 mm diameter and less exposed to atmosphere shall be of

stainless steel and those above 12 mm diameter shall preferably be of stainless steel or of mild steel hot dip galvanised to RDSO’s specification No. ETI / OHE / 18 (4 / 84).

10. TESTING 10.1 Type tests : The following tests shall be carried out at the works of the manufacturer

or at a reputed testing laboratory in the presence of the Indian Railway representative(s) on the prototype unit of the current transformer, as per IS : 2705 (Pt. I & III) and as modified or amplified as under : -

10.1.1 Visual inspection : It shall comprise :

(a) Checking of the layout, terminal markings, mounting arrangement, labelling and any other items.

(b) Quality of painting and anti-ruse treatment.

(c) Quality of workmanship and finish as well as provision of all parts, fittings

and accessories. 10.1.2 Temperature – rise test.

This test shall be carried out on the current transformer for higher rating fitted with approved terminal connector for full-load and for overload specified in clause 5.1 (xiv). The temperature – rise under specified overload shall not exceed the following values : (a) Winding - 500 C

(temperature – rise measurement by the resistance method).

(b) Insulating oil - 400 C (temperature-rise measurement by thermo-meter)

(c) Terminal connector - 400 C (temperature – rise measurement by thermo-meter)

The above values are with reference to an ambient temperature of 450 C. 10.1.3 Impulse voltage test :

The lightning impulse voltage withstand test shall be done on the primary windings with test voltages specified in clause 5.1 (xi) .

10.1.4 Short – time current test :

The short-time thermal (rms) and dynamic (peak) current withstand tests shall be done to verify the ability of the current transformer and the terminal connectors fitted thereto to withstand the rated short-time current specified in clause 5.1 (x).

307

The current transformer shall be deemed to have passed the test if the conditions laid down in clause 7.6.3 of IS : 2705 (Pt. I) are satisfied.

10.1.5 Excitation test and plotting of magnetising characteristic curves :

The curve shall be drawn at least upto that point, where an increase of 100 per cent in voltage results in an increase of 50 per cent in current.

10.2 Type test on accessories. 10.2.1 Porcelain bushing :

The following tests shall be carried out on a prototype unit of 52 kV or 72.5 kV or 123 kV or 145 kV or 245 kV (as the case may be) class bushings in accordance with IS : 2099 and IS : 5621. (i) Dry power-frequency withstand voltage test. (ii) Wet power-frequency withstand voltage test. (iii) Dry lightning impulse voltage withstand test. (iv) Thermal stability test. (v) Temperature-rise test. (vi) Thermal short time current withstand test. (vii) Dynamic current withstand test. (viii) Cantilever load withstand test. (ix) Measurement of partial discharge quantity (as per IS : 6209). (x) Tightness test at flange or other fixing device. (xi) Temperature cycle test.

10.2.2 Tests on terminal connectors :

The terminal connectors shall be from the approved supplier of RDSO. In case these are not from the approved supplier of RDSO, the following tests shall be carried out : i) Visual inspection and verification of dimensions. ii) Tensile test. iii) Resistance test. iv) Temperature-rise test at normal and specified overload. v) Short-time current test. vi) Chemical analysis of materials used.

10.3 In addition tot he above tests, all routine tests detailed in clause 10.7 shall be carried out on the test unit.

10.4 If the prototype of a current transformer conforming to this specification has been

approved for earlier supplied to Indian Railways, the testing of prototype again may be waived provided that no change in the design or material (s) used have been made.

10.5 Manufacturers type test certificates in respect of the tests carried out on (a)

Porcelain housing and (b) terminal connector, as per relevant IEC recommendations / IS Specifications shall be submitted by the successful tenderer for approval.

308

10.6 The tenderer may quote separately his charges for conducting short-time current (thermal) and dynamic current withstand tests described in clause 10.1.4, hereof. No charges shall be payable for any other type and routine / acceptance tests.

10.7 Routine tests / Acceptance tests.

Every current transformer shall be subject to the following tests at the manufacturer’s works as per IS : 2705 (Pt. I) and IS : 4322.

10.7.1 Verification of terminal markings and polarity. 10.7.2 High voltage power-frequency tests on primary windings, The windings shall be subject to the following --------------------------------------------------------------------------------------------------

(a) Nominal system voltage, kV 220 132 110 66

(b) Voltage to be applied between winding & earth, kV (rms)

460 275 230 140

(c) Voltage to be applied between two sections of primary winding, kV (rms)

2 2 2 2

-------------------------------------------------------------------------------------------------- 10.7.3 High voltage power-frequency withstand test on secondary winding : - 3 kV (rms)

for one minute. 10.7.4 Accuracy tests : The accuracy test shall comprise the following : -

(a) Current error & phase displacement at the rated primary current. (b) Composite error at rated accuracy limit primary current.

10.7.5 Measurement of insulation resistance between primary winding and secondary

winding with a 2500 V Megger; and that between secondary winding & earth with a 500 V megger.

10.7.6 Measurement of secondary winding resistance and its computation at 750 C. 10.7.7 Measurement of partial discharge of windings. 11 TECHNICAL DATA AND DRAWINGS. 11.1 The tenderer shall furnish along with his offer in the proforma attached at Appendix

‘C’, the guaranteed performance data and other technical particulars of the equipment. Evidence in the form of type test reports for rated insulation level i.e. rated impulse withstand voltage test, rated power frequency (wet) withstand test, rated power frequency (dry) withstand test, temperature – rise test and short-time current withstand test on the current transformer offered shall be furnished.

309

11.2 The tenderer shall specifically indicate in a statement attached with his offer, his compliance with each clause and sub-clause of this specification. A separate statement shall be attached with the offer indicating reference to the clause where the tenderer deviates therefrom together with detailed remarks / justification. If either the statement of compliance or statement of deviation is not attached with the offer, it is not likely to be considered. If there are no deviations, a ‘NIL’ statement shall be attached.

11.3 The tenderer shall furnish the following drawings as per Indian Railways standards

in sizes of 210 mm x 297 mm or any integral multiples thereof. A format of the title sheet is attached at Appendix ‘D’.

(a) Outline general arrangement drawing giving the overall dimensions of the

current transformer. (b) Internal arrangement of the current transformer including cross-sectional

views. 11.4 The tenderer shall also furnish the following information along with his offer : -

(a) Excitation characteristic curve. (b) Manufacturer’s test certificates of : -

(i) Winding wire, (ii) Oil seal gaskets (iii) insulating oil (iv) pressure release device etc.

(c) The tenderer shall furnish the detailed calculation and basis in support of the

minimum knee point voltage. 11.5 The successful tenderer shall be required to submit for approval the following

detailed dimensioned drawings as per Indian Railways standard in sizes of 210 mm x 297 mm or any integral multiples thereof :-

(a) General outline drawing showing mounting arrangement, relative position of

primary and secondary terminals, CT earthing and position of various parts, fittings and accessories.

(b) Cross-sectional view along with its internal details. (c) Porcelain housing / bushing including its clamping arrangement. (d) Name and rating Plate with the diagram of connections (both in English and

Hindi). (e) Details of primary terminals and links used for changing the transformation

ratio. (f) Secondary terminals and terminal box. (g) Details of metallic bellow, if provided as well as its operation (h) Detailed part drawings for :

(i) Oil level gauge ; (ii) Nitrogen gas filling value ; (iii) Pressure release device ; (iv) Cable gland ; (v) Terminal connector; (vi) Earthing terminals and (vii) Oil draining pipe with plug.

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11.6 After approval, six copies of approved drawings along with two sets of reproducible prints shall be supplied to each consignee (s). Besides, two copies of drawings along with one set of reproducible prints shall be supplied to the Director General (Traction Installation), Research Designs & Standards Organisation, Lucknow (India).

11.7 The successful tenderer shall supply five copies of the instruction/maintenance

manual for the current transformer to each consignee (s) and two copies to the Director General (Traction Installation(, Research Designs and Standards Organisation, Lucknow (lndia).

12. SPARES

The tenderer shall furnish along with his offer a list of spare (with cost) recommended by him for maintenance of current transformer for a period of two years.

13. ERECTION, TESTING AND COMMISSIONING. 13.1 The Transformer shall be erected by the purchaser under the supervision of a

competent Engineer of the successful tenderer / manufacturer / supplier. The current transformer shall be subjected to the specified proving / pre-commissioning tests by the Railway’s Engineer at site and with which the successful tenderer / supplier / manufacturer shall also be fully associated. For this purpose, prior intimation regarding the date and location of tests shall be given by the purchaser to the supplier / manufacturer / successful tenderer.

14. TRAINING OF INDIAN RAILWAY’S ENGINEERS. 14.1 The offer shall include the training of two Engineers of the Indian Railways free of

cost at the manufacturer’s works in India or abroad and at the maintenance depots / workshops on a railway system or other public utility where current transformers of similar / identical design are in operation. The total duration of training for each engineer shall be 12 weeks of which approximately 6 weeks will be at manufacturer’s works and 6 weeks on a railway system or other public utility. The cost of travel to the country of manufacturer and back will be borne by the Indian Railways. Other details shall be settled at the time of finalising the contract or Purchase order.

15. WARRANTY. 15.1 Each current transformer supplied against a purchase order / contract in which this

specification is quoted, irrespective of origin (imported or indigenous), shall be guaranteed for trouble – free and satisfactory performance for a period of 24 months from the date of supply or 18 months from the date of commissioning at the sub-station on Indian Railways, whichever period is shorter. Details of warranty clause, the extent of responsibility and other relevant aspects shall be included in the purchase order or contract. The tenderer shall furnish detailed terms and conditions in this regard in his offer.

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The successful tenderer shall make necessary arrangements for closely monitoring the performance of the current transformer through periodical (preferably once in two months during the warranty period) visits to the sub-station for on the spot detailed observations. Arrangements shall also be made for spare parts to be kept readily available with the manufacturer / supplier / successful tenderer to meet exigencies warranting replacement so as to put back the current transformer in service without unduly long interruption of traction power supply.

16. PACKING AND SHIPMENT. 16.1 The current transformer shall be transported from the manufacturer’s works to the

destination by rail, road or sea as determined in the contract / purchase order. The parts, fittings and accessories which are liable to damage during transit shall be separately packed / crated and despatched so as to reach destination along with the transformer tanks. Any opening created on the current transformer tank by the removal of any parts, fittings and accessories shall be closed by suitable blanking plates.

A general packing list, for the various components of each current transformer shall be furnished. The packing has to be done properly so that no damage may be done during transit.

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APPENDIX – ‘C’ to the specification No. ETI / PSI / 117 (7 / 88) SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS -------------------------------------------------------------------------------------------------------- S. No. Description Unit of measurement Data -------------------------------------------------------------------------------------------------------- 1. Name of the manufacturer 2. Country of origin

3. Standard Governing Specification


5. (a) Nominal system voltage kV

(b) Highest system voltage kV

6. (a) Rated primary current Amp.

(b) Rated secondary current Amp.

(c) Rated transformation ratio

7. Rated burden VA

8. Accuracy class

9. Rated accuracy limit factor

10. Current error at rated primary current Percent

11. Phase displacement at rated primary current

Minutes

12. Composite error at rated accuracy Percent

13. Rated short-time current and duration.

(a) Thermal (Ith) KA (RMS) for one sec.

313

(b) Dynamic (I dyn) KA (peak)

14. Temperature-rise of the windings (by resistance method) over an ambient temperature of 460 C

(a) At rated current 0 C

(b) At 100% overload for 5 minutes 0 C

15. Partial discharge level PC

16. Particulars of windings :

(a) Primary windings : (i) Type (ii) No . of turns (iii) Current density at rated current (iv) Size of conductor (v) Class of insulation

(b) Secondary windings :

(i) Type (ii) No . of turns (iii) Current density at rated current (iv) Size of conductor (v) Class of insulation (vi) Resistance computed to 750 C (vii) Insulating materials used

Amp / mm2 Amp / mm2 Ohm

(c) Rated insulation levels : (i) One minute power frequency withstand voltage (ii) Inter-section withstand voltage

of primary windings. (iii) Impulse withstand voltage

kV (rms) kV (rms) kV (rms)

17. Particulars of core :

(i) Type

(ii) Flux density :

(a) at rated primary current (b) at 15 times rated primary

current

(iii) Thickness of steel laminations

Tesla Tesla mm

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(iv) Whether CRGC steel

stampings are used?

(v) Watt – loss per kg. of steel.

(vi) Knee-point e.m.f.

18. Particulars of porcelain housing/bushing :

(i) Specification to which it conforms.

(ii) Make of manufacturer

(iii) Power frequency withstand voltage for one minute

(a) Dry (b) Wet

kV (rms) kV (rms)

(iv) Dry lightning impulse withstand voltage, 1.2 / 50 micro-second wave shape

kV (peak)

(v) Visible power frequency discharge voltage

kV (rms)

(vi) Creepage distance in air

a. Protected b. Total

mm mm

(vii)Weight of porcelain housing/bushing kgs.

19. Overall dimensions :

(i) Length mm

(ii) Width mm

(iii) Height mm

20. Weights :

(i) Total weight of copper used

(a) Primary winding (b) Secondary winding

kgs. kgs.

(ii) Weight of core kgs.

(iii) (a) Quantity of insulating oil (b) Weight of insulating oil

lits. kgs.

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(iv) Total weight kgs.

21. Particulars of terminal connector :

(i) Name of manufacturer (ii) Rated current (iii) Temperature-rise above an ambient of 450 C

(a) at rated current (b) at 150 per cent of rated current

for 15 minutes

Amp. 0 C 0 C

-------------------------

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29TH NOVEMBER 1988 ADDENDUM / CORRIGENDUM SLIP NO. 1 TO TECHNICAL SPEC IFICATION NO. ETI / PSI / 117 ( 7 / 88) FOR 220 kV or 132 kV or 110 / kV or 66 kV CURRENT TRANSFORMERS Page 7, Clause 7.2 Add after the existing entries :

“The porcelain housing shall be of single piece construction i.e. , without joint in the porcelain body”.

Page 8, Clause 7.5 In the first line after the word connectors add “and porcelain housing”.

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ADDENDUM / CORRIGENDUM SLIP NO. 2 (MARCH 1989) TO T ECHNICAL SPECIFICATION NO. ETI / PSI / 117 ( 7 / 88) FOR CURRENT TRANSFORMERS 220 Kv, 132 kV, 110 kV and 66 kV. -------------------------------------------------------------------------------------------------------- Sl. CLAUSE NO. & AS AMENDED No. DESCRIPTION -------------------------------------------------------------------------------------------------------- 1 2 3 -------------------------------------------------------------------------------------------------------- 1. Clause 6.5 (Page 7)

Type & General construction. Replace the existing entries by the following :- “The current transformer shall have a single core with wound primary. The primary winding insulated from each other and connected to terminals P1, P2, C1 & C2. It shall be possible to change the transformation ratio by connecting C1 with C2 for series configuration or P1 with C1 & P2 with C2 for parallel configuration. For connecting these terminals in series or parallel configuration, suitable links of adequate section made of copper flat shall be provided. The nuts and checknuts used for connecting these links shall be made of copper. Only copper conductors shall be used for primary and secondary windings.”

2. Clause 10.1 (Page 9) Testing.

Replace the existing entries by the following : “Only after all the designs and drawings have been approved and clearance given by RDSO to this effect, the manufacturer shall take up manufacture of the prototype unit for RDSO inspection. It is to be clearly understood that any changes required to be done in the prototype unit - as required by RDSO shall be done expeditiously. The following tests shall be carried out at the works of the manufacturer or at a reputed testing laboratory in the presence of the Indian Railways representative (s) on the prototype unit of the current transformer as per IS : 2705

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(Pt. I & III) and as modified or amplified as under”.

3. Clause 10.8 (Page 12) Bulk manufacture.

Add this new clause 10.8 as under : “Only after clear written approval of the results of the tests on the prototype unit is communicated by RDSO/Purchaser to the manufacturer, shall he take up bulk manufacture of the ordered current transformers – which shall be strictly with the same material and process as adopted for the prototype. In no circumstances shall material, other than those approved in the designs/ drawings and/ or the prototype, be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype”.

4. Clause 11.1 (Page 12) Technical data & drawings.

Replace the existing entries by the following : “The information furnished in ‘Schedule of guaranteed performance, technical & other particulars’ (Annexure A) shall be complete in all respects. If there is entry like ‘shall be furnished later’ or blanks are left against any item, the tender is not likely to be considered as such omissions causes delay in finalising the tender. Evidence in the form of type test reports for basic insulation level i.e., rated impulse withstand voltage test, rated power frequency (wet) withstand test, rated power frequency (dry) withstand test, temperature rise test and short time current withstand test on the current transformer offered shall be furnished.”

----------------------------

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22nd December, 1989 Addendum / corrigendum slip No. 3 (Dec. 1989) to Technical Specification No. ETI / PSI / 117 (7 / 88) for Current Transformers 220 / 132 / 110 / 66 kV. ---------------------------------------------------------------------------------------------------------- S. Clause No. & description As amended No. ---------------------------------------------------------------------------------------------------------- 1. 5.1 (XV) (Page – 6)

Knee – point voltage

The existing entries may be deleted.

2. 5.1 (XV) (Page – 6) Add the following line against the existing entries: “5.1 (XV) Secondary winding resistance at 750C (max.) : 0.3 ohms.”

3. 7.2 (Page – 7) Bushing & Terminal arrangement.

Add after the existing entries (ref. Amendment No. 1 Nov. 1989) the following as a separate para : “The material of clamping rings / flanges used shall conform to MCI Grade BM – 340 of IS : 2108 or to SGCI Grade : 400 / 12 of IS : 1865 or to Aluminium alloy Grade : 4450 of IS : 617. The mass of zinc coating shall not be less than 1000 gm / m2.

4. 10.1 (Page - 9) Type tests.

Add after the first para of existing entries (as stipulated in amendment slip No. 2 (March 1989). “Before giving the call to RDSO / the Chief Elect. Engineer for inspection and testing of the prototype of the equipment, the manufacturer shall submit a detailed test schedule consisting of schematic / circuit diagrams for each of the tests and nature of the test, venue of the test and the duration of each test and the total number of days required to complete the test at one stretch. Once the schedule is approved, the test shall invariably be done accordingly. However, during the process of type testing or even

320

later, RDSO representative reserves the right to conduct any additional test (s) besides those specified herein, on any equipment / sub system or system so as to test the equipment to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the manufacturer and RDSO / the Chief Elect. Engineer during the process of testing as regards the type tests and/ or the interpretation and accept ability of the type test results, it shall be brought to the notice of the Director General / Traction Installations, RDSO / the Chief Elect. Engineer as the case may be whose decision shall be final and binding.

5. 11.4 (c) (Page – 13) Tech. data & Drawings.

Add after the existing entries : “For calculations purpose the lead resistance may be presumed as 0.4 ohms.”.

-------------------------------------

321

Received vide RDSO’s letter No. ETI / PSI / Spec / 10 Dt. 25 / 4 / 90 Addendum / Corrigendum Slip No. 4 (April 1990) to Specification

No. ETI / PSI / 117 (7 / 88) for Current Transformers, 220 / 132 / 110 / 66 kV.

-------------------------------------------------------------------------------------------------------- S. No. Clause No. & As amended Description -------------------------------------------------------------------------------------------------------- 1. 5.1 (ii), Page – 4,

Number of winding. The existing word “two” against “Secondary”, may be read as “one”.

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ADDENDUM / CORRIGENDUM SLIP NO. 5 (JUNE 1990) To Specification No. ETI / PSI / 117 (7 / 88) for Current Transformers, 220 / 132 / 110 / 66 kV.

------------------------------------ ---------------------------------------------------------------------------------------------------------- Sl. Clause No. & As amended No. description ---------------------------------------------------------------------------------------------------------- 1. 5.1 (x) (Page – 5)

Rated short-time current. For 132 kV nominal system voltage, replace the figures “25.0” and 62.5” in column 3 & 4 respectively with “31.5” and “78.75” respectively.

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Addendum / Corrigendum Slip No. 6 (September – 1992) to the technical specification No. ETI / PSI / 117 (07 / 88) for current transformer, 220 / 132 / 110 / 66 kV. --------------------------------------------------------------------------------------------------------- S. No. Clause No. and As Amended. description. --------------------------------------------------------------------------------------------------------- 1. 10.1 (Page – 9)

Type tests. The existing matters may be replaced by the

following : i) Once a purchase order is placed for supply of a

current transformer the designs and drawings shall be furnished to the purchaser / Director General (Traction Installations) Research Designs and Standards Organisation, DG (TI), RDSO Lucknow, as the case may be, within the period stipulated in the order. Only after all the designs and drawings have been approved for prototype tests and a written advice given to that affect, shall be successful tenderer / manufacturer take up manufacture of the prototype of the transformer. It is to be clearly understood that any change or modification required by the above authorities to be done in the prototype shall be done expeditiously, not withstanding approval having already been given for the designs and drawings. Such change or modification shall be incorporated in the drawings as indicated in Clause 14.1.

ii) Prior to giving a call to the Purchaser / DG (TI), RDSO, Lucknow, for inspection and testing of the prototype, the successful tenderer / manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the tests and the number of days required to complete all the tests at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the purchaser reserves the right to conduct any additional test (s), besides those specified herein, on any equipment / item so as to test the equipment/ item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and representative of successful tenderer /

324

manufacturer and representative of the purchaser / DG (TI), RDSO, Lucknow, during the process of testing as regards the procedure for type tests and / or the interpretation and acceptability of the results of type tests, it shall be brought to the notice of the Purchaser / DG (TI), RDSO, Lucknow as the case may be, whose decision shall be final and binding. Only after the prototype transformer is completed and ready in each and every respect, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with atleast 15 days notice for the purpose

iii) In the event of the tests not being carried through the completion at one stretch for any reason attributable to the successful tenderer / manufacturer and it is required for the representative of the Purchaser / Director General (Traction Installation), Research Designs and Standards Organisation, DG (TI) RDSO, Lucknow, to go again or more number of times to the works of the successful tenderer / manufacturer or other place (s) for continuing and / or completing the tests on the prototype (s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser / DG (TI) RDSO, Lucknow, the costs for the representative having to visit the works or other place (s) for the tests more than once. The costs as claimed by the Purchaser / DG (TI), RDSO, Lucknow, shall be paid through a demand draft to the concerned accounts officer of the Purchaser / DG (TI), RDSO, Lucknow, as shall be advised to the successful tenderer / manufacturer.”

iv) The following type tests shall be carried out on the prototype current transformer at the works of the successful tenderer / manufacturer or at a reputed testing laboratory in the presence of the representative of the purchaser / DG (TI), RDSO, Lucknow, in accordance with the relevant specifications and as modified or amplified as under. :

325

Addendum/Corrigendum slip No. 7 (August 2005) to the RDSO specification No. ETI/PSI/117(7/88) for 132 kV current transformer to be used in Mumbai area on 110 kV side of 30 MVA transformers at railway traction sub-stations which may be operated in parallel on the 25 kV side. S.No. Clause No./

Page No.


1. Annexure -C Details of 132 kV current transformers to be used in Mumbai area. This is to be read along with details given in the subject specifications.

New Annexure - C added

(B.P.Singh) Director/TI-I

for Director General/TI

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ANNEXURE-C 1.0 SCOPE This part of specification cover design, manufacture, testing, inspection, packing and supply, of 145 kV class outdoor, current transformers with CT ratio of 1200-800-400/5A to the specification given below to be used in Mumbai area on 110 kV side at traction sub-station with 30MVA transformers and required to be operated in parallel with adjacent traction sub-stations. 2.0 RATING AND OTHER PARTICULARS

i) Type Single phase, oil filled natural air cooled outdoor

ii) No. of cores

4

iii) System voltage a) Nominal system voltage, kV b) Highest system voltage, kV

132 145

iv) Rated primary / secondary currents a) Primary current, Amp b) Secondary current, Amp

1200

5

v) CT Ratio 1200- 800-400/5 A vi) Rated frequency 50 Hz +/- 3% vii) Class of insulation A viii) a)Short time current rating (thermal)

for 3 second, kA b) Short circuit withstand current (3 sec.), kA c) Short time current rating (Dynamic), kA (peak)

40

40

100

ix) Rated insulation level a) One minute 50 Hz withstand voltage/induced over-voltage, kV (rms) b) Impulse withstand voltage, Positive and negative polarity (1.2/50 microsecond wave), kV (peak)

275

650

x) Minimum creepage distance of insulator (31mm/kV), mm

4495

327

xi) Temperature rise Maximum temperature rise of windings immersed in oil

500C over an ambient of 500C

xii) Rated over load

150% of full load for 15 minutes

xiii) Rated burden & class of accuracy of different cores

Core-1 Core-3 Core-2&4 Protection R. met Protection

Burden in VA

40 40

Accuracy Class

5P20 0.2 PS

Instrument Security Factor

- <5 -

Knee point Voltage

- - >750V

Iex (max) at Vk/2

- - < 100mA

Rct (max) - - < 1.0 Ohm at max.tap)

2.0 a) Multi-ratio specified shall be obtained by taps on secondary side. b) The values specified above for metering & protection core shall be met for the lowest tap. (except Rct and knee point voltage for PS core which is at the highest tap). c) P1 and P2 markings to be permanently riveted. d) CTs shall be of dead tank design. e) Power factor terminal (test tap) shall be provided inside the secondary terminal box. f) The disposition of various CT cores and detailed drawings alongwith SOGP shall be furnished for RDSO’s approval before manufacture is taken up. 2.1 Construction

The current transformers shall be hermetically sealed. They shall be suitable for upright mounting on steel structures. They shall be provided with nitrogen cushions/stainless steel bellows. CTs shall be suitable for hot line washing. The current transformer winding shall be housed in a galvanised tank suitable for outdoor duty. Earthing arrangement shall be provided for CT tank.

328

2.2 Tank Fabrication

Tank shall be fabricated from tested quality low carbon steel suitable for welding and of adequate thickness. The tank shall be designed to withstand mechanical shocks during transportation, vacuum filling of oil and continuous internal pressure over normal hydrostatic pressure of oil and short circuit forces.

The construction of tank shall be designed to prevent ingress of water into or

leakage of oil from the tank. All bolted connections shall be fitted with weather proof, hot oil resistant gasket in between (Butile Nitrile/ Neoprene Rubber), for complete oil tightness. If gasket is compressible, metallic stops shall be provided to prevent over-compression.

Tank fabrication drawings shall be submitted for approval before the manufacturing

is taken up.

2.3 SPECIAL CONSTRUCTION NOTE

After the internal elements such as primary & secondary windings are sealed in the tank with procelain shell, the assembled CTs shall be subjected to vacuum & heat treatment and finally filled with degasified oil in vacuum.

3.0 General 3.1 Current transformers shall be provided with unthreaded stud terminals at top for connections to 110 kV, 50 mm OD aluminium busbar. The primary current terminals shall be of tinned copper. 3.2 The current transfer area of the terminals shall be adequate to meet the temperature rise requirements as per IEC 44-1/ IS: 2705 for CTs. The cross-section area of the terminal shall be indicated in the drawings. 3.3 Mechanical load test on primary terminals: Test reports are to be submitted as per IEC 44-1. 3.4 The burdens specified for different cores refer exclusively to connected burden and should exclude the bleeder resistances if any. Current transformer’s guaranteed burdens and accuracy class are to be intended as simultaneous for all cores.

329

3.5 CTs shall be provided with a capacitance test tap in the HV lead to enable future monitoring of conditions of HV insulation. 3.6 Earthing terminal shall be provided in the secondary junction box for earthing of secondary winding of CT. 3.7 The alignment and centre line of CT primary terminals shall be correct so as to avoid bending of connections. 3.8 The CT secondary terminal box shall be of GI (IP 55) and shall be provided with collar to prevent entry of moisture & good neoprene gaskets designed to prevent entry of foreign particles. Junction box shall be sufficiently large to connect 1100V upgrade, 4Cx6 Sq.mm cables through cable glands for all the secondary cores. 3.9 CT secondary terminals shall be terminated to stud type non disconnecting terminal blocks inside the terminal box. CT secondary terminals shall be provided with lock nuts. 3.10 All ferrous parts exposed to atmosphere including main tank, secondary terminal box & top metallic should be hot dip galvanized. 3.11 The current transformers shall be supplied complete with insulating oil conforming to IS: 12463 and railway requirements. The insulating oil shall be procured from the manufacturers approved by RDSO. The successful tenderer/manufacturer shall submit test certificates as per IS: 12463 for oil. 3.12 The tenderer shall furnish their compliance or otherwise against each clause/sub-clause of the technical specification. If the tenderer wishes to deviate from the provision of any clause/sub –clause, he shall furnish the full details with justification for such deviation. 3.13 Detailed drawings of CT alongwith SOGP shall be furnished for RDSO’s approval before manufacture is taken up. 3.14 This CT shall be used for following additional protective devices/relays.

i) Fiber optic line differential protection ii) Directional over current relay iii) LBBU relay (LBB- breaker failure relay) iv) Busbar differential low impedance type protections relay v) Energy metering

330

4.0 The following Type &Routine tests as per IEC44-1, IS: 2705 and RDSO specification

no. ETI/PSI/117 (7/88) with A&C slip no. 1 to 6 shall be conducted on the current transformer required for Mumbai area under DC-AC conversion

4.1 Type tests

1. Visual inspection. 2. Temperature rise test.

3. Impulse voltage test.

4. Short time current test.

5. Excitation test and plotting of magnetizing characteristic curves.

6. Radio interference test.

7. Seismic withstand test.

8. Thermal stability test.

9. Thermal coefficient test i.e. measurement of tan-delta as a function of temperature.

10. The CTs shall be subjected to fast transient test in order to evaluate the aging

characteristics of the CT insulation. This test is to be done to assess the CT performance in service to withstand the high frequency over voltage generated due to closing and opening operations of isolators.

331

4.2 Routine Tests

1. Dimensional check 2. Verification of terminal marking and polarity.

3. Power frequency voltage withstand tests on primary winding.

4. Power frequency voltage withstand tests on secondary winding. 5. Accuracy tests

a) Current error and phase displacement at the rated primary current b) Composite error at rated accuracy limit primary current

6. Measurement of knee point voltage, exciting current and ISF test (only for

metering core). 7. Measurement of winding resistance test.

8. Insulation resistance measurement test.

9. Inter-turn over-voltage test. 10. Partial discharge test (PD value shall be less than 5 pC).

11. Capacitance and tan delta value measurement (tan delta value shall be less than 0.5%). 12. Oil leakage test.

332

RDSO Specification No. ETI / PSI / 117 (07/88) for 110 kV current Transformer The following amendments are made in addition to the addendum and corrigendum slips issued to the specification Sl.No. Para No. Amendment 1. 3.1 (ii) : Substitute 0ºC with 5ºC 2. 3.1 (iv) : Substitute 200 kg/sqm with 112.5 kg/sqm

3. 4.1 : In line no. 8, substitute “40 km and 80 km” with “6.5 km

and 25” km. 4. 4.1.1 : In line no.9 delete “feeder” before circuit breaker

: In line no. 10, substitute “ an interrupter” with “feeder circuit breaker”

5. 6.2 : In line 1, delete “either” after sealed type In line 1&2, delete “or provided with metallic bellows” and Delete the words “In case of inert gas filling”

6. 10.1 : In line 2, substitute the word “Indian Railway” with

“Clients” In line 3, delete the word “ Prototype” 7. 10.2.1 : In line 1, delete the word “prototype” 8. 10.6 : Delete 9. 11.6 : In line 2, delete the sentence “Besides….. Lucknow(India)” 10. 11.7 : In line 2, delete the words “and two copies……….

Lucknow(India)” 11. 13.1 : In line 1, substitute “Purchaser” with “Contractor” 12. 15.1 : In line 3, substitute “24” with “36” and

In line 4, substitute“18” with “24”

333



SPECIFICATION FOR

25kV AC, 50 Hz, SINGLE PHASE, OIL FILLED

CURRENT TRANSFORMER. WITH CT RATIO OF

(i) 1000 – 500 / 5 A (FOR GENERAL PURPOSE) (ii) 1500 – 750 / 5 A (FOR HEAVY HAUL DUTIES)

FOR


No. ETI / PSI / 90 (06 / 95)

334




SPECIFICATION

FOR

25 kV AC, 50 Hz, SINGLE PHASE, OIL FILLED

CURRENT TRANSFORMER

WITH CT RATIO OF

(iii) 1000 – 500 / 5 A (FOR GENERAL PURPOSE) (iv) 1500 – 750 / 5 A (FOR HEAVY HAUL DUTIES)

FOR


ISSUED BY


MINISTRY OF RAILWAYS, MANAK NAGAR, LUCKNOW 226 011.

335


RESEARCH DESIGN AND STANDARDS ORGANISATION Specification No. ETI/PSI/90 (06/95)

SPECIFICATION FOR 25 KV AC, 50 Hz, SINGLE PHASE, OIL FILLED

CURRENT TRANSFORMER. 1.0 SCOPE 1.1 This specification covers the design and testing of outdoor type 25 kV, Current

Transformer (CT) for installation in Railway’s traction substation in any part of India for operation of protective devices and indicating instruments.

1.2 The CT shall be complete with all parts, fittings and accessories necessary for its

efficient operation. All such parts, fittings and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not.

1.3 This specification supersedes the earlier specification no. ETI/PSI/90 (9/87). GOVERNING SPECIFICATION

The CT shall, unless otherwise specified, conform to the following standards and codes of practices (latest version) which shall be applied in the manner altered, amended or supplemented by this specification and Indian Electricity Rules, wherever applicable:

IS : 5 Colours for ready mixed paints and enamels.

IS : 226 Specification for structural steel (standard quality)

IS : 335 Specification for New Insulating Oils. IS : 1271 Classification of insulating materials for electrical

machinery and apparatus in relation to their thermal stability in service.

IS : 1367 Technical supply conditions for threaded steel

fasteners.

IS : 1554 Specification for PVC insulated (heavy duty), (Part I) electrical cables for working voltage upto and

including 1100 volts.

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IS : 1570 Schedule for wrought steel for general engineering (Part V) purposes. IS : 1866 Code of practice for maintenance and supervision of mineral insulating oil in equipment.

IS : 2071 Methods of high voltage testing.

IS : 2074 Ready mixed paint, air drying red oxide zinc chrome,

priming.

IS : 2099 Specification for bushings for alternative voltages above 1000 V.

IS : 2705 Current Transformers.

IS : 2927 Brazing alloys.

IS : 3024 Specification for electrical steel sheets (oriented).

IS : 3347 12 to 17.5 kV bushings (porcelain and metal parts).

IS : 4253 Cork and Rubber. (Part II) IS : 5561 Specification for Electric Power connectors.

IS : 5621 Specification for Hollow insulators for use in

electrical equipments.

IS : 8570 Press paper for electrical purposes.

IS : 8572 Paper covered flexible/stranded copper conductor for transformer leads.

IS : 9224 Specification for low voltage fuses.

IS : 10028 Code of practice for selection, installation and (Part I

to III) maintenance of transformers.

IS : 11322 Method for partial discharge measurement in instrument transformers.

IEC : 137 Bushing for alternating voltage above 1000 V.

IEC : 185 Current transformers. IEC : 815 Guide for the selection of insulator in respect of

polluted conditions.

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2.2 In case of any conflict between the contents of the above specifications and this

specification, the latter shall prevail. 2.3 Any deviation from this specification, proposed by the tenderer, intended to

improve the performance, utility and efficiency of the equipment, will be given due consideration, provided full particulars of the deviation with justification therefor, are furnished. In such a case, the tenderer shall quote according to this specification and the deviation, if any, proposed by him shall be quoted as an alternative(s).

3. ENVIRONMENTAL CONDITIONS 3.1 The CT shall be suitable for outdoor use in moist tropical climate and in areas

subject to heavy rainfall, pollution due to industry and marine atmosphere and severe lightning. The limiting weather conditions which the transformer has to withstand in service are indicated below:

i) Maximum ambient air temperature 50 C. ii) Maximum daily average ambient air 40 C. temperature. iii) Maximum relative humidity 100 % iv) Annual rainfall Ranging from

1750 mm to 6250 mm.

xix) Maximum number of thunder storm 85 days per annum.

xx) Maximum number of dust storm 35 days per annum.

xxi) Number of rainy days per annum 120 xxii) Basic wind pressure 200 kgf/m.

xxiii) Altitude Not exceeding 1000 m.

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3.2 The CT is also be subjected to vibrations on account of trains running on nearby

railway tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 ms to 70 ms lies in the range of 30 micron to 150 microns at present, with the instantaneous peak going upto 350 microns. These vibrations may become more severe as the speeds and loads of trains increase in future.

4. TRACTION POWER SUPPLY SYSTEM General Scheme.

Power is received from the grid network of the State Electricity Board at 220 kV / 132 kV / 110 kV / 66 kV, either at individual traction substation (TSS) or at a single point of supply from where it is transmitted through Railway’s own transmission lines to the traction substations, with line sectioning facilities provided as required. 25 kV power supply for traction is drawn through a single phase step down traction transformer. The primary winding of this transformer is connected to any two nominated phases of the incoming three phase lines or to the two incoming phase lines and on the secondary side, either of the two terminals of the 25 kV winding is connected to the traction overhead equipment, while the other is solidly earthed and connected to the running traction rails.

Each transformer has its associated circuit breakers on the primary and secondary sides, with a separate set of 25 kV circuit breakers called “Feeder Circuit Breakers” for feeding the traction overhead equipment (OHE) lines.

Adjacent TSS are fed from different phases of the three phase system in rotation. Neutral sections in front of sectioning and paralleling post (SP) are provided in the 25 kV OHE for segregating the different phases. In between the TSS and SP, sub-sectioning and paralleling post (SSP) are provided for paralleling the up and down line OHE and also for sectionalizing and fault localization. The attached sketch no. ETI/PSI/702-1 MOD ‘C’ at Annexure – I, shows the general scheme for traction power supply system.

The supply to the OHE can be switched ON / OFF through interrupters which do not open automatically on fault, but can be closed on to a fault. The fault is cleared by the feeder circuit breaker provided at the traction substation.

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Normally power supply from a TSS extends upto the SP on either side of the substation, but in case of an emergency necessitating total shutdown of the substation, power supply from adjacent TSS on either side of the failed substation can be extended upto the failed substation by closing the bridging interrupters at the two SPs.

The scheme of protection to be provided at each of traction substations comprises of the following three systems: (i) Protection of the 220 / 27 kV or 132 / 27 kV or 110 / 27 kV or 66 / 27 kV

traction transformer installed at the traction substation. (ii) Protection of the 25 kV overhead equipment.

(iii) Protection of 220 / 132 / 110 / 66 kV transmission lines.

The relays for transformer protection as well as feeder protection shall be suitable for operation from current transformer. The following relays shall be fed by the CT. A schematic diagram showing the protection scheme is given at Annexure – II. (i) Relays / instruments fed by feeder protection CTs.

a) Distant protection relay (MHO) b) Wrong phase coupling relay (MHO) c) Instantaneous over current relay. d) Transducer for telemetry of feeder current. e) Transducer for telemetry of MVA (maximum demand). f) Transducer for telemetry of power factor. g) Restricted earth fault relay. h) Thermal over-current relay. i) Ammeter.

(ii) Relays / instruments fed by transformer protection CTs.

a) IDMT over current relay. b) Restricted earth fault relay. c) Ammeter.

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5. RATING AND GENERAL DATA The CT shall be designed for the following rating and other particulars :

(i) Type Oil filled, single phase, natural air cooled, low reactance, sealed, outdoor type.

c) Rated voltage 25 kV (varying from 19.0 kV to 27.5

kV, some times touching 30 kV). d) Highest voltage 52 kV.

for equipment Um.

e) Rated frequency 50 Hz. ± 3%. f) Rated secondary current 5 A

g) Rated transformation ratio (i) 1000 – 500 / 5

(ii) 1500 – 750 / 5 h) Rated burden 60 VA i) Accuracy class 5 P

j) Rated accuracy limit factor 15

k) Rated short time thermal 25 kA.

current

l) Rated dynamic current 62.5 kA peak

m) Rated insulation level :-

1) Power frequency 95 kV withstand voltage

2) Impulse withstand 250 kV

voltage, peak. n) Resistance of secondary Not greater than 0.3 ohm at 75 C.

winding

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o) Class of insulation Class ‘A’. p) Temperature rise limits The temperature rise over an ambient

temperature of 50 C shall not exceed the values indicated below: (a) Winding : 50 C (measured by the

resistance method). (b) Insulating oil : 40 C (measured by

thermometer method).

(c ) Current carrying parts in air:40 C (measured by the thermometer).

(d) Hot spot temperature : not to

exceed 115ºC. q) Terminal bushing :-

1) Voltage class and 52 kV class, 2000 A rated current 2) Minimum creepage 1300 mm distance of the porcelain housing.

6. CONSTRUCTIONAL FEATURES 6.1 The CT shall have a single core with wound primary. The primary winding shall be

spilt in two sections insulated from each other and connected to terminals P1, P2, C1 & C2. It shall be possible to change the transformation ratio by connecting C1 with C2 for series configuration or P1 with C1 and P2 with C2 for parallel configuration. For connecting these terminals in series or parallel configuration, suitable links of adequate section made of copper flat shall be provided. The nuts and check nuts used for connecting these links shall be made of copper. Alternatively, tappings on the secondary windings may be offered to give the specified transformation ratios. In this case suitable shorting link of adequate section made of copper shall be provided. Only copper conductors shall be sued for primary and secondary windings.

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6.2 The core shall be built up of high permeability, low loss, cold rolled grain oriented,

non-ageing, electrical silicon steel laminations conforming to IS:3024. The laminations shall be coated on both sides with suitable insulation, capable of withstanding stress relief annealing. The laminations for the core shall be free from waves, deformations and signs of rust. In assembling the core, care shall be taken to ensure that no air gaps are formed.

6.3 Each of the core clamping bolts and the core clamping frame work shall be

insulated from the core laminations and tested after completion of the core assembly to ensure that they withstand a voltage of 2 kV rms with respect to core for a duration of 60 s.

6.4 The CT shall be of sealed construction with nitrogen gas above the insulating oil

and shall be adequately protected against any leakage of nitrogen gas or oil and ingress of moisture. All joints in the construction of the CT shall be suitably sealed so as to provide lasting gas, air, oil and water tightness. The number of gasketed joints shall be restricted to the minimum.

6.5 The CT core and winding shall be dried under vacuum till appropriate values of

insulation resistance and power factor have been obtained. It shall then be filled up under vacuum with transformer insulating oil conforming to IS:335. The characteristics of insulating oil before energizing the new CT shall conform to the parameters as stipulated in IS : 1866.

6.6 The HT terminal of the CT shall be located below the minimum oil level as marked

on the oil level gauge mounted on the oil expansion chamber. 6.7 The port shall be provided on the oil expansion chamber to serve the purpose of oil

filling and also for fixing the nitrogen gas filling assembly. The nitrogen gas filling assembly shall be screwed into the oil filling port and shall have its own leak proof sealing. A screwed cap shall be provided on the oil filling port with a gasket or ‘O’ ring provided at suitable location. The internal and external threads provided on the oil filling port shall be of adequate length and shall confirm to the ‘Precision grade’ as defined in IS : 1367.

6.8 The oil draining pipe provided on the bottom tank shall have suitable internal

threads over an adequate length and a threaded plug should be screwed into the pipe. The assembly of the threaded pipe and the plug shall conform to the “precision grade” as defined in IS: 1367. In addition, a gasket or ‘O’ ring shall be provided at suitable location in the assembly.

6.9 The CT secondary terminal shall be housed in a weather proof terminal box fitted

with a cable gland suitable for 4mm, 2 core, PVC insulated and PVC sheathed copper cable of 1100 volts grade, conforming to IS:1554 (Part I). Facilities for short circuiting the secondary terminals shall be provided within the terminal box. An earthing line shall be provided in the terminal box to enable earthing of one end of

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the secondary winding. The CT shall also be provided with a standard 10 A test winding.

6.10 Normally, no joint shall be used in the winding conductor. If a joint becomes

inescapable, it shall be brazed with high silver alloy grade Ba Cu Ag6 conforming to IS : 2927 or electrically butt-welded.

6.11 No grading ring shall be used in the construction of the CT. 6.12 All leads and connections shall be mechanically strong, adequately insulated,

protected against mechanical injury and rigidly clamped to withstand dynamic stresses due to short circuits.

6.13 All the bolted mechanical and electrical connections in the assembly of CT shall be

provide with standard locking arrangements to prevent their becoming loose in service due to vibrations etc.

6.14 Alternatively, a fully hermatically sealed CT may be offered. In this case a stainless

steel bellow shall be provided at the top of oil, to take care of expansion / contraction of oil due to thermal variations. As the oil will not come in contact with air during the service life of CT, there may not be any necessity to provide Nitrogen gas cushion at the top of oil. However, the detailed design / drawing for the same shall be submitted along with complete technical details to assess the suitability of the design being offered.

7. BUSHINGS AND TERMINAL CONNECTORS 7.1 The porcelain housings shall be of a single piece construction i.e. there shall be no

joint in the porcelain. The shed profile shall have a lip at the extremities, but free from ribs on the underside so as to avoid accumulation of dust and pollutants and to permit easy cleaning.

7.2 The design of the bushing shall be such that stresses due to expansion and

contraction in any part of the bushing shall not lead to its deterioration / breakage. 7.3 The porcelain housing shall conform to IS:5621 and shall withstand the following

test voltages :- (i) Rated short duration wet power frequency 95 kV withstand voltage (ii) Rated lightning impulse withstand voltage, 250 kVp peak

7.4 The CT terminals and terminal fittings shall be capable of carrying the rated current

continuously without exceeding the temperature rise limits of any part. They shall be free from corona and shall not cause radio interference.

7.5 The general construction of the CT and in particular the relative positions of the

primary terminals and their height above base, secondary terminal box, earthing terminals and the base mounting channel shall conform to sketch placed in Annexure – III.

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7.6 The bushing / housing terminals shall be provided with a rigid type terminal connector on the other side. These terminals as per Research, Designs and Standards Organisation’s (RDSO) drawings indicated below shall be supplied along with each CT.

(i) Expansion type terminal connector - Drg. No. ETI.PSI/P/11060

MOD ‘E’ (at Annexure IV) (ii) Rigid terminal connector - Drg. No. ETI.PSI/P/11090

MOD ‘C’ (at Annexure V)

These terminals shall be suitable for 50 mm diameter Aluminium tubular bus bar and for terminal pad of CT for horizontal takeoff.

7.7 Primary and Secondary bushings and terminal connectors shall be from RDSO’s

approved suppliers only. 8. FASTENERS 8.1 All fasteners of 12 mm diameter and less, exposed to atmosphere shall be of

stainless steel and those above 12 mm diameter shall preferably be of stainless steel or of mild steel hot dip galvanized to 610 g/m of zinc. The material of the stainless steel fasteners shall conform to IS: 1570 (Pt.V) Grade 04, Cr 17 Ni 12 MO 2.

9. PAINTING

All steel surfaces exposed to weather shall be given one primer coat of zinc chromate after descaling the surface and two coats of enamel gray paint to shade 631 of IS: 5.

10. SOURCES OF SUPPLY FOR WINDING WIRE, GASKETS AND ‘O’ RINGS. 10.1 Polyveniyl Acetal enamel or polyester enamel wire shall be used for secondary

winding. Wires, gaskets and ‘O’ rings certified only by Bureau of Indian Standards (BIS) shall be use din the manufacture of the CT.

10.2 The successful tenderer / manufacturer shall be required to finish the following

information with respect to the winding wire, gaskets and ‘O’ rings:

(i) Source of supply

(ii) Reference to standard specification to which the material conforms.

(iii) Reports of type tests carried out in terms of the relevant Indian Standard specification.

11. RATING PLATE

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The CT shall be provided with a rating plate (both in Hindi and English) of weather proof material. The entry on the plate shall be indelibly marked by etching, engraving or stamping. The following items shall be shown on the rating plate :

(i) Type of transformer (ii) Governing specification (iii) Manufacturer’s name and country of origin (iv) Manufacturer’s serial number and type designation (v) Year of manufacture (vi) Rated output and corresponding accuracy class (vii) Rated frequency (viii) Highest voltage for equipment (ix) Rated current (x) Rated transformation ratio (xi) Maximum temperature rise over an ambient of 50 ºC


(xii) Total mass (xiii) Rated Insulation level (xiv) Connection diagram.

12. PARTS, FITTINGS AND ACCESSORIES 12.1 The following parts, fittings and accessories shall be supplied with each CT :

(i) Rating and diagram plate (ii) Terminal marking plate (iii) Weather proof terminal box (iv) Cable gland to take wire, 4mm / 1100 V grade PVC insulated, PVC

sheathed unarmoured, heavy duty copper cables to IS :1554 (Part-I) (v) Lifting lugs (vi) Two glavanised earthing terminals (vii) Terminal connectors (viii) Plain rollers (ix) Oil filling port and nitrogen gas filling value (x) Oil drain pipe with plug (xi) Pressure relief device (xii) Oil level sight gauge (tough acrylic plastic / prismatic).

12.2 The parts, fittings and accessories for the CT shall be only those manufacturers

approved by RDSO. If any item from fresh manufacturers / sources are proposed to be used, it shall have to be type tested in the presence of RDSO’s representative and approval obtained before procuring the item for use.

13. DRAWINGS

The successful tenderer / manufacturer shall submit for approval the following detailed dimensioned drawings to the Purchaser / Director General (Traction Installation), Research, Design and Standards Organisation (DG(TI), RDSO) Lucknow as per Indian Railway Standards in sizes of 210 mm x 297 mm or any integral multiple thereof.

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(i) Outline general arrangement of the CT indicating plan, front elevation, side elevation with all parts, fittings and accessories, electrical clearances, and salient guaranteed particulars position of terminals and base mounting channels.

(ii) Integral arrangement of the CT.

(iii) Cross sectional view clearly indicating core and windings with material specifications, various clearances, supporting / clamping arrangement of core, coil assembly and arrangement of primary and secondary side leads inside the CT.

(iv) Untanking details.

(v) Porcelain bushing including cross sectional view, shed profile, creepage distance, clamping arrangement and other salient electrical and mechanical characteristics.

(vi) Rigid and flexible terminal connectors

(vii) Primary terminals and details of link and mounting arrangement.

(viii) Secondary terminals and secondary terminal box.

(ix) Rating and diagram plate, both in English and Hindi version.

(x) Detailed part drawings of the following

a) Oil level gauge b) Nitrogen gas filling valve and oil filling port. c) Oil drain pipe with plug. d) Pressure relief device. e) Cable gland. f) Earthing terminals

(xi) Any other drawing considered necessary by the successful tenderer /

manufacturer and / or Purchaser.

A format of the title sheet to be adopted by the successful tenderer / manufacturer for preparation of the drawings is attached at Annexure- VI.

The provisionally approved drawings shall be modified, if need be, as a result of changes necessitated during type test or as desired by the Purchaser / DG(TI), RDSO, Lucknow. The modification shall be first got approved from the Purchaser / DG(TI), RDSO, Lucknow and then incorporated in the drawing. If there are no modifications at all the provisionally approved drawings shall be finally approved.

After approval, six copies of each of the approved drawings alongwith two sets of reproducible prints for each drawing shall be supplied to each consignee(s). Besides two copies of drawings alongwith one set of reproducible prints shall be supplied to DG (TI), RDSO, Lucknow (INDIA)

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The successful tenderer / manufacturer shall supply at least two copies of “operation / maintenance manual” for each CT to each consignee(s). Two copies of the manual shall be supplied to DG (TI) RDSO, Lucknow.

14. TESTING OF TRANSFORMER 14.1 General 14.4.1 Once a purchase order is placed for supply of a CT the designs and drawings

together with the Quality Assurance Plan (QAP) shall be furnished to the Purchaser/DG (TI), RDSO, Lucknow as the case may be within the period stipulated in the order. Only after all the designs and drawings as well as the QAP have been approved for prototype tests and a written advice given to that effect, shall the successful tenderer/manufacturer take up manufacture of the prototype of the CT. It is to be clearly understood that any change or modification required by the above authorities to be done in the prototype shall be done expeditiously, not withstanding approval having already been given for the designs and drawings. Such change or modification shall be incorporated in the drawing as indicated in Clause 13.3.


testing of the prototype, the successful tenderer/manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the tests and the number of days required to complete all the tests at one stretch. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the Purchaser/ DG (TI), RDSO, Lucknow reserves the right to conduct any additional test(s), besides those specified herein, on any equipment / item so as to test the equipment / item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and representative of the Purchaser / DG (TI), RDSO, Lucknow, during the process of testing as regards the procedure for type tests and/or the inspection and acceptability of the results of type tests, it shall be brought to the notice of the Purchaser / DG (TI), RDSO, Lucknow, as the case may be, whose decision shall be final and binding. Only after the prototype CT is completed and ready in each and every respect, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with atleast 15 days notice for the purpose.

14.4.3 In the event of the tests not being carried through to completion at one stretch for

any reason attributable to the successful tenderer / manufacturer and it is required for the representative of the Purchaser / DG (TI) RDSO to go again or more number of times to the works of the successful tenderer / manufacturer or other place(s) for continuing and / or completing the tests on the prototype(s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser / DG (TI) RDSO, Lucknow, shall be paid through a demand draft to the concerned accounts officer of the Purchaser / DG (TI), RDSO, Lucknow, as shall be advised to the successful tenderer / manufacturer.

14.5 Type Tests.

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The type tests shall be carried out on the prototype CT at the works of the successful tenderer / manufacturer or at any reputed laboratory or testing house in the presence of the representative of the Purchaser / DG (TI) RDSO, Lucknow, in accordance with IS : 2705 and as altered, amended or supplemented by this specifications. The following shall constitute the type tests :. (i) Temperature rise test. (ii) Lightening Impulse test. (iii) Short time current test. (iv) High voltage power frequency wet withstand voltage test. (v) Determination of errors according to the requirement of the appropriate

accuracy class. 14.5.1 Temperature rise test

The temperature rise test shall be done in accordance with clause 7.2 and 9.7 of IS : 2705 (Part I) and shall be carried out for full load on the CT for the parallel configuration of the winding i.e. 1000 / 5A or 1500 / 5Afor general and heavy haul duties of the CT respectively and fitted with the approved terminal connectors. The test shall be done continuously without any power supply interruption. In case interruptions of power supply do take place for some reason, then the entire test shall be repeated after steady state conditions are attained.

14.5.1.1 The points to be ensured during the temperature rise test, shall be:

(i) Only alcohol in glass thermometers shall be used for the measurement of the ambient temperature.

(ii) The temperature of the winding shall be determined by the resistance

method only. 14.5.1.2 The temperature rise shall not exceed the limit laid down in clause 5.1(xv). 14.5.2 Lightning Impulse test

This test shall be done in accordance with Clause 9.1 of IS: 2705 (Part-I) on the primary winding at a test voltage of 250 kV peak.

14.5.3 Short time current tests.

The short time thermal and dynamic (peak) current withstand tests shall be done in accordance with clause 9.6 of IS : 2705 (Part I) to verify the ability of current transformers and the fitted terminal connectors to withstand the rated short time current specified in clause 5.1 (x) and (xi). The current transformer shall be deemed to have passed the tests subject to satisfying the conditions laid down in clause 9.6.3 of IS : 2705 (Part I).

14.5.4 High voltage power frequency wet withstand voltage test

This test shall be done in accordance with Clause 9.9 of IS: 2705 (Part-I). The test voltage applied shall have 95 kV.

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14.5.5 Determination of errors according to the requirement of the appropriate accuracy

class.

The CT shall conform to accuracy class SP13. Test shall be done for current error, phase displacement and composite error in accordance with Clause 7.1.1 and 7.1.2 of IS: 2705 (Part-3) to prove compliance with the requirements as indicated under clause 5.1 (vi) and 5.1 (ix) of this specification.

14.6 Routine Tests

The routine tests shall be performed on each CT including prototype unit. The following shall constitute the routine tests: (i) Visual Examination (ii) Insulation resistance test. (iii) Over voltage inter turn test. (iv) Determination of error according to the requirement of appropriate accuracy

class. (v) Measurement of resistance of the windings. (vi) Verification of terminal markings and polarity. (vii) Power frequency (dry) withstand voltage test on primary winding. (viii) Power frequency (dry) withstand voltage test on secondary winding

14.6.1 Visual examination

A general examination shall be made to check that the CT conforms to the provisionally approved drawings, various items are accessible for maintenance, the quality of workmanship and finish are of acceptable standards and all parts, fittings and accessories are provided.

14.6.2 Insulation resistance

The insulation resistance of the primary windings and earth and between primary windings and secondary winding shall be measured using 2.5 kV megger. The insulation resistance between secondary winding and earth shall be measured using 500 V megger.

14.6.3 Over voltage inter turn test

The over voltage inter turn test shall be done in accordance with clause 9.5 of IS : 2705 (Part-I).

14.6.4 Accuracy test The accuracy test shall comprise of: a) current error and phase displacement at the rated primary current. b) composite error at the rated accuracy limit of primary current.

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The above tests shall be conducted in accordance with clause 7.2.1 and 7.2.2 of IS : 2705 (Part 3) to prove compliance with the requirements as indicated under clause 5.1 (viii) and 5.1 (ix) of this specification.

14.6.5 Measurement of resistance of the windings

The resistance of each of the windings shall be measured and computed at 75 C. The secondary winding resistance shall not exceed 0.3 ohm. 14.6.5.1 Verification of terminal markings and polarity.

The terminal markings and polarity shall be verified in accordance with approved drawing as per clause 9.2 of IS : 2705 (Part 1).

14.6.6 Power frequency (dry) withstand voltage test on primary winding

The test shall be conducted as per clause 9.3 of IS : 2705 (Part I). The test voltage applied shall be as given below: a) Between primary winding and earth 95 kV rms b) Between two sections of the primary winding 2 kV rms

14.6.7 Power frequency (dry) withstand voltage test on secondary winding

The test shall be conducted as per clause 9.4 of IS : 2705 (Part I). The test voltage applied shall be 3 kV rms.

14.7 Tests on parts, fittings and accessories. 14.7.1 Porcelain housing.

The porcelain housing shall be tested in accordance with IS : 5621 and the certificate for compliance with the standard shall be furnished. The porcelain housing shall also meet the requirement of clause 7.3 of this specification.

14.7.2 Terminal connector.

The terminal connector shall be tested in accordance with IS : 5561 and the certificate for compliance with the standard shall be furnished.

14.7.3 Pressure relief device.

The pressure relief device (PRD) shall be subjected to air pressure test and leakage test. The PRD should operate at a pressure between 0.4 and 0.45 kg/cm.

14.7.4 Insulating oil

The sample of insulating oil drawn from the prototype unit shall be tested in accordance with IS : 1866.

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14.7.5 Failure of prototype

In the event of prototype CT failing in any one of the tests, further testing shall be discontinued. The manufacturer after carrying out all the modifications as required on the CT, shall offer a fresh prototype for carrying out all the tests indicated above.

14.8 Waiver of tests

If the prototype of the CT to this specification has already been approved in connection with previous supplies to Indian Railways, fresh type testing may be waived at the discretion of the Purchaser, provided that no changes whatsoever in the design or materials used or the process of manufacture have been made. However, the Purchaser reserves the right to conduct type tests if he deems it necessary to do so in the light of experience gained from previous supplies.

14.9 Bulk manufacture

Only after approval of original tracings of drawings incorporating changes, if any, as a result of the prototype tests and clear written approval of the results of the tests on the prototype is communicated by the Purchaser / Director General (TI), RDSO, Lucknow, to the successful tenderer / manufacturer, shall be taken up bulk manufacture of the CT, which shall be strictly with the same materials and process of manufacture as adopted for the prototype. In no circumstances shall materials other than those approved in the design / drawings and/or during the prototype testing be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

15.9 TECHNICAL DATA AND DRAWINGS.

The tenderer shall furnish along with his offer, in the proforma at Annexure-VII, the Schedule of Guaranteed Performance, technical and other particulars (SOGP) for the CT. The particulars shall be correct and complete in all respects. If there is any entry like “shall be furnished later” or a blank against any item, the offer is not likely to be considered as the evaluation of the offer is rendered difficult and can not be compared with other offers, if any.

The tenderer shall specifically indicate in a “statement of compliance” attached with the offer his compliance with each and every clause of this specification. In case the tenderer wishes to deviate from any clause of this specification he may do so giving reference to the clause(s) with the reasons / justification for the deviation. This shall be in the form of a separate statement called the “statement of deviation”. If there is no deviation at all, a separate “Nil” “statement of compliance” and “statement of deviation” are not attached with the offer, it is not likely to be considered for the reason that it is an incomplete offer which can not be properly evaluated and compared with other offers, if any.

The tenderer shall furnish the following drawings as per Railways Standards in sizes

210 mm x 297 mm or any integral multiples thereof, along with his offer:

(i) Outline general arrangement drawing giving the overall dimensions of the Transformer.

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(ii) Rating and diagram plate.

(iii) Internal arrangement of the CT including cross-sectional views.

16. SPARES 16.1 The tenderer shall also quote separately for the following essential spares for every

lot of upto 5 CTs or part thereof:

(i) One primary bushing complete with parts and fittings. (ii) Terminal connector for primary side bushing terminal.

16.2 A separate quotation shall be furnished for any other spares that the manufacturer

considers as necessary for maintenance of the CT. 17. AFTER SALES SERVICE 17.1.1 The successful tenderer / manufacturer shall make necessary arrangements for

closely monitoring the performance of the CT through periodical (preferably once in three months during the warranty period) visits to the location where they have been erected for observations and interaction with the operating and maintenance personnel of the Indian Railways. Arrangements shall also be made by the successful tenderer / manufacturer for emergency / standby spare parts being kept readily available to meet exigencies warranting replacement so as to keep the equipment in service with least down time.

17.2 The successful tenderer / manufacturer shall respond promptly and in a workman like

manner to any call given by Indian Railways for any assistance by way of attending to failures, investigation into the causes for failures including conducting of tests, if any, to be done and such other items with a view to see that the CT serves the purpose for which it is intended. Besides technical guidance to ensure proper operation and maintenance of the CT shall be constantly rendered.

18. WARRANTY 18.1 The successful tenderer / manufacturer shall warrant that all equipment shall be free

from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally acceptable standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

18.2 This warranty shall survive inspection of, payment for and acceptance of the

equipment, but shall expire 24 (Twenty four) months after the delivery at ultimate destination or 18 (Eighteen) months from the date of commissioning and proving test of the equipment at ultimate destination, whichever period expires earlier, except in respect of complaints, defects and/or claims notified to the successful

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tenderer / manufacturer within 3 (Three) months of the expiry of such date. Any approval or acceptance of the Purchaser of the equipment shall not in any way limit the successful tenderer / manufacturer’s liability.

18.3 The successful tenderer / manufacturer’s liability in respect of any complaints,

defects and/or claims shall be limited to the furnishing and installation of replacement parts free of any charge or the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer / manufacture within 3 (Three) months of their being first discovered during the warranty period of 3 (Three) months from the date of expiry of warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned.

18.4 The successful tenderer / manufacture shall, if required, replace or repair the

equipment of such portion thereof as is rejected by the Purchaser free of cost at the ultimate destination or at the option of the Purchaser, successful tenderer / manufacture shall pay to the Purchaser value thereof at the Contract Price or in the absence of such price at a price decided by the Purchaser and such other expenditure and damages as may arise by reason of the breach of the conditions herein specified.

18.5 All replacement and repairs that the Purchaser shall call upon the successful tenderer

/ manufacture to deliver or perform under this warranty shall be delivered and performed by the successful tenderer / manufacture, promptly and satisfactorily and in any case within 2 (Two) months of the date of advice to this effect.

18.6 If the successful tenderer / manufacture so desires, the parts that are removed may

be taken over by him or his representative for disposal as he deems fit at the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.


repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer / manufacture, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

18.8 The decision of the Purchaser in regard to the successful tenderer / manufacture’s


19. TRANSPORTATION OF THE CT. 19.1 The CT may be transported according to the transport facilities available for the

route, viz. rail, road or sea. All parts, fittings and accessories which are liable to damage during transit shall be removed and packed / crated separately. Detached parts may be packed / crated and sent with CT along with the packing list, so that all the parts are available at the destination with the unit. The packing has to be done properly so that no damage occurs during transit.

19.2 The various components of each CT shall be securely packed in wooden crates

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and boxes. General packing list, together with weight and overall dimensions of packing cases shall be furnished for each CT indicating the following:

--------------------------------------------------------------------------------------------------- Crate No. Description of Approx. gross Approx. outside Item / component weight in kg. dimensions In the crate --------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------

19.3 As far as possible, the gross weight of the crate / box shall be so kept that it can be conveniently handled by two persons. 19.4 In case of overseas supplies, packing shall be sea-worthy. 19.5 Necessary instructions for handling and storage of all items shall be included along with the packing lists.

**************

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Annexure VII to Specification No. ETI/PSI/90(6/95)

SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND OTHER PARTICULARS FOR 25 kV CURRENT TRANSFORMER. Note : Guaranteed particulars are to be established by actual test / test reports. ------------------------------------------------------------------------------------------------------------ S. No. Description Unit of

measurement ------------------------------------------------------------------------------------------------------------ 1. Name of the manufacturer 2. Country of manufacture 3. Reference to specification based on

which performance data is based 6. Manufacturer’s type designation 7. Rated system voltage 8. Highest voltage for equipment kV 9. Rated primary current A 10. Rated secondary current A

11. Rated frequency Hz. 12. Rated burden VA 13. Rated transformation ratio 14. Accuracy class 15. Rated accuracy limit factor 16. Current error at rated primary current % 17. Phase displacement at rated primary current Minute 18. Composite error at rated accuracy limit %

primary current 19. Rated short time thermal current for 1 s. kA 20. Temperature rise over a maximum

ambient temperature of 50 C after

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continuous full load operation (i) of oil by thermometer (ii) of winding by resistance

21. Core particulars

(i) Type of core (ii) Maximum Flux density at T

(a) Rated primary current T (b) 15 times rated primary current T

(iii) Thickness of steel stamping mm (iv) Grade of core material and

conforming specification

(v) Watt loss / kg. (vi) Minimum knee point (e.m.f) voltage V

(vii) Existing current at knee point (e.m.f)

voltage

22. Winding particulars

(i) Type of primary winding (ii) Current density in primary winding A/mm2

at rated current

(iii) (a) Size and number of turns of mm primary winding

(b) Size and number of turns of mm

secondary winding

(iv) Resistance of primary winding at 75 C Ohm (v) Resistance of secondary winding at 75 C Ohm (vi) Conformation to IS specification No.

(vii) Class of insulation

(a) Primary winding

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(b) Secondary winding

(viii) Type of joints in the winding, if any. (ix) Rated lightning impulse withstand voltage kV peak

(x) Rated short duration power frequency kV

(wet) withstand voltage of primary

23. Porcelain housing

(i) Name of manufacturer (ii) Manufacturer’s type designation

(iii) Standard specification on which the

performance data are based

(iv) Voltage class kV (v) Rated current

(vi) Minimum creepage distance mm

(vii) Weight kg.

24. Weights and dimensions :

a. Net weight of core kg b. Net weight of copper in

(a) Primary winding kg (b) Secondary winding kg

c. Net weight of steel enclosure fitting kg d. Total weight of CT kg

e. Volume of oil l

f. Weight of oil kg

g. Overall dimensions of the CT

(a) Height mm (b) Length mm (c) Breadth mm

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25. Name of suppliers and conforming IS specification No.

(i) Terminal connector (ii) Fasteners

(a) Stainless steel (b) M.S. hot dip galvanized

(iii) Winding wire (iv) Gaskets

(v) ‘O’ rings

(vi) Core material

Other particulars : 26. Is the CT fitted with lifting lugs? Yes / No 27. Is the porcelain housing of bushing of

single piece construction? Yes / No 28. Whether the CT is of sealed construction

with Nitrogen at top? Yes / No

29. Is the shed profile of porcelain housing free from under ribs but has a lip ? Yes / No

30. Pressure relief device provided or not? Yes / No 31. Is clause by clause statement of Yes / No

compliance attached ?

32. Is the statement of deviation, if any, attached? Yes / No 33. Are fasteners of 12 mm dia and less exposed to Yes / No

atmosphere of stainless steel to grade 04 Cr 17 Ni 12 Mo 2 to IS 1570 (Part II)?

34. Are the fasteners of more than 12 mm Stainless steel /

Specification No. ETI/PSI/147 (04/92) dia exposed to atmosphere stainless steel or Hot dip galvanized. MS hot dip galvanized?

35. (i) Are all the parts, fittings and Yes / No

accessories from RDSO’s approved manufacturer’s

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(ii) If not, list the items which are to be type tested in the presence of RDSO representative. 36. Are all the drawings required as per Yes / No

Clause 15.3 (I, II & III) attached? 37. Is warranty as per Clause 18.0? Yes / No 38. Is the list of spares furnished? Yes / No ************

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Addendum and Corrigendum Slip No. 1 (April 96) to the Technical Specification No. ETI/PSI/90 (06/95) for 25 kV AC, 50 Hz, Single Phase, Oil filled Current Transformer with CT ratio (i) 1000 – 500 / 5 A & (ii) 1500 – 750 / 5 A.

Sr. No Clause & Description As amended

1. 3.1 (i & ii) (page 4); Environmental Conditions

Read the unit as ‘ºC’ instead of ‘C º’

2. 5.1 (xv – a, b & c) (page 7); Rating and general data.

Read the units as ‘ºC’ instead of ‘C º’

3. 6.9 (page 9); Constructional feature.

The unit at the existing 2nd line may read as ‘mm2’ instead of ‘mm’.

4. 6.14 (page 9); Constructional features.

The word ‘ct’ at the existing 5th line may be read as ‘CT’.

5. 8.1 (page 10); Fasteners.

The unit at the 4th line may be read as ‘g/m2’, instead of ‘g/mo’.

6. 12.1 (iv) (page 11); Parts, fittings and accessories.

The unit ‘mm’ may be read as ‘mm2’.

7. 14.2.1 (page 14); Temperature rise test.

The first sentence of the paragraph may be replaced by the following: “The temperature rise test shall be done for the parallel configuration of the windings i.e. 1000 / 5 A or 1500 / 5 A for general and heavy haul duties of the CT respectively. The test shall be in accordance with clause 7.2 & 9.7 of IS: 2705 (Part I) and shall be carried out, fitted with the approved terminal connectors, for rated current of 1000 A for general purpose CTs (ratio – 1000 / 5A) and for rated current of 1250 A for heavy haul duties (ratio – 1500 / 5A).”

8. 14.4.3.1 (page 17); Pressure relief device

The existing unit at the third line may be read as ‘kg / cm2’

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9. SOGP Annexure VIII

i) Item 18, (page 2);

Temperature rise.

ii) Item 18, 203,4 (page 2) iii) Item 32, (page 5)

Add the following before the existing entries: “18. Temperature rise”. The unit ‘C’ may be read as ‘ºC’ The second line of the existing entries “Specification no. ETI/PSI/14 (04/92) may be deleted”. Under the unit column the existing entries may be read as,

362

Addendum and Corrigendum Slip No. 2 (June 97) to the Technical Specification no. ETI/PSI/90 (06/95) for 25 kV AC, 50 Hz, Single Phase, Oil filled Current Transformer with CT ratio (i) 1000 – 500 / 5 & (ii) 1500 – 750 / 5.

Sr. No Clause & Description As amended

1. 14.4.3.1 – Pressure relief device.

The existing second sentence may be replaced with the following : “The PRD is designed to moperate at a pressure between 2.5 to 4.5 kg / cm2”.

363

Addendum / Corrigendum Slip No.3 (October 2001) to the Technical Specification No.ETI/PSI/90(06/95) for 25 kV, AC, 50 Hz,Single phase, Oil filled current transformer with CT ratio (i) 1000-500/5, & (ii) 1500-750/5 S.No. Clause No. Description As amended

1.0 Clause 4.1.1

Page-5 General scheme Replace the existing line from Board at 220

kV/132 kV/110 kV/66 kV either “with” Board /Tata Power at 220 kV/132 kV/110 kV/66 kV/22 kV, either” . Replace the existing term “step down” with “step up step down”.

2.0 Clause 4.1.3 Page-5

General scheme After the existing line “the attached sketch No.ETI/PSI/702-1 mod “C at annexure-I” add “and sketch No.ETO/PSI/709” at Annexure-1A”.

3.0 Clause 4.2.(i) Page-5

General scheme Replace the existing clause with following : “ Protection of the 220/27 kV or 132/27 kV or 110/27 kV or 100/27 kV or 66/27 kV or 22/27 kV traction transformer installed at the traction substation.”

4.0 Clause 4.2. (iii) Page-6

General scheme Replace the existing clause with following: “ Protection of the 220/132/110/100/66/22 kV transmission lines”.

5.0 Clause 5.1. (viii) Page-6

Accuracy Class Add PS (for 1500-750 5 CT only) with the existing entry of SP i.e. the accuracy class will become 5P and PS (FOR 1500-750 5ct only).

6.0 Clause 5.1. (xvii) Page-7

Minimum Knee point voltage (for PS Class )

Add a new clause as 5.1 (xvii) with following entry 210 Volts for any of the winding taps (1500-750 5).

7.0 Clause 5.1. (xviii) Page-7

Maximum exciting current (for PS class)

Add a new clause as 5.1(xvii) with following entry 500 mA at rated knee point voltage.

8.0 Clause 14.2 Page - 15

Type Tests Add a new clause as 14.2.6 with following entry : “PS class CTs shall be subjected to additional type tests as per clause 6.1 to 6.3 of IS : 2705 Pt-IV.

9.0 Clause 14.3 Page - 17

Routine Test Add a new clause as 14.3.9 with following entry : “PS class CTs shall be subjected to additional routine tests as per clause 6.1 to 6.3 of IS : 2705 Pt-IV.

(B.P. Singh) For Director General/TI

364

Addendum / Corrigendum Slip No.4 (June 2003) to the Technical Specification No. ETI /PSI/90 (6/95) for 25 kV, AC, 50 Hz,Single phase, Oil filled current transformer with CT ratio 3000-1500/5A, to be used in Mumbai Area.

Page 1 of 2

S.No. Clause No. Description As amended 1. Covering Page of

the specification Page-1

CT ratio of Add “(iii) 3000-1500/5A (for both sides of 22/25 kV, 30 MVA transformer to be used in Mumbai area )”

2. Clause 2.1 item 10 of page 3

Governing specification

IS 2074 is to be replaced with ISO/EN 12944 on protective paint system.

3. Clause No.4.1.3 Page -5

General Scheme

After the existing line “the attached sketch No.ETI/PSI/702-1 mod C at Annexure-I” add “and sketch No.ETI/PSI/709 mob B” at Annexure-I/A”.

4. Clause 5.1 Rating and general data 4.1 Clause 5.1 (vi) of

Page 6 Rated transformation ratio.

Add “iii) 3000-1500/5”

4.2 Clause 5.1 (viii) of Page 6

Accuracy Class

Replace the existing entry with following : i) 5P – for a) 1000-500/5 and b) 1500-750/5 ii) PS – for a)1500-750/5 and – (For Mumbai b) 3000-1500/5 area)

4.3 Clause 5.1 (xvii) of Page 7

Minimum Knee point voltage (for PS class)

Replace the existing entry with following : a) 210 volts for any of the winding taps (1500- 750/5A) b) 360 volts for any of the winding taps (3000-1500/5A).

5. Clause 9.1 of Page 10

Painting Replace the existing clause with following : “All steel surfaces exposed to weather shall be properly descaled/grit blasted. The epoxy and polyurethane protective paints as per ISO/EN 12944 have to be provided for proper protection against corrosive and coastal environments and give life of approx. 12-15 years. All the external surfaces of the current Transformer shall be given first coat of epoxy zinc rich (having minimum 83% metallic zinc) primer (50 micron thickness), intermediate coat of epoxy chemical and corrosion resistant High Build Epoxy Intermediate paint (100 micron thickness) and

365

Addendum / Corrigendum Slip No.4 (June 2003) to the Technical Specification No. ETI /PSI/90 (6/95) for 25 kV, AC, 50 Hz,Single Phase, Oil filled current transformer with CT ratio 3000-1500/5A, to be used in Mumbai Area.

Page 2 of 2

S.No. Clause No. Description As amended

final coat of Glossy Aliphatic Acrylic Polyurethane Coating paint ( 50 micron thickness. ) The total dry film thickness of the paints shall be minimum 200 micron. The shade of paint shall be gray as shade 631 of IS: 5. Same paints have to be applied at damaged surfaces, if any, at site during erection / commissioning of the transformer. One final coat of polyurethane paint has to be applied to ensure proper smoothness and finish.

366

RDSO Specification No. ETI / PSI / 90 (06/95) for 25 kV Current Transformer. The following amendments are made in addition to the addendum and corrigendum slips issued to the specification. Sl.No. Para No. Amendment 1. Para 3.1(i) Substitute 50°C with 45°C

2. Para 3.1 (ii) Substitute 4 0°C with 35°C 3. Para 3.1(viii) substitute 200 Kgf./.m2 with 112.5 kgf.m2

4. Para 4.1.4 Substitute the following in place of existing clause :

“The supply to the OHE can be switched on / off through circuit breakers provided at SSP/SP/TSS and any fault on OHE is cleared these”.

5. Para 4.2 (iii) Deleted 6. Para 4.2.1 (i) a) & b) Delete the word “(MHO)” in (a) & (b) 7. Para 5 (xv) In line 2, substitute 50°C with 45°C 8. Para 7.7 In line 1, add the word “preferably” after the word

“shall be” 9. Para 11.1 (xi) Substitute 50°C with 45°C 10. Para 12.2 In line 1, substitute the word “only” with “preferably

from” 11. Para 18.2 In line 2, substitute “24” with “36” & in line 3,

substitute “18” with “24”. 12. Scheduled of garanteed particulars Sl.No.18 : Substitute 50°C with 45°C

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lR;eso t;rs

Specification No. TI/SPC/PSI/30/TRN/1050

for

30MVA, 110/27kV SINGLE -PHASE TRACTION POWER TRANSFORMER

WITH ON LOAD TAP CHANGER

FOR USE IN MUMBAI SUB-URBAN AREA

DECEMBER 2005

ISSUED BY ___________________________________________________________


(MINISTRY OF RAILWAYS) MANAK NAGAR, LUCKNOW-226 011

368

Specification No. TI/SPC/PSI/30TRN/1050 For 30 MVA, 110 /27 kV Traction Transformer

SPECIFICATION FOR 30MVA, 110 /27kV single -phase traction power transformer SPECIFICATION No. TI/SPC/PSI/30TRN/1050 Amendment Number

Amendment /Revision Total pages including drawings

Date of Issue

0 NA 77 01.12.2005 PREPARED BY CHECKED BY APPROVED BY

SIGNATURES DATE DESIGNATION SE-I/TI Dir/TI-I Sr.EDTI COPY NUMBER

ISSUED BY …………….. SIGNAGURE ……………..DATE ……………………. ISSUED TO …………………………………………………………………………….

369

INDEX

Clause No. Description 1.0 Scope Duties of traction transformer in 25kV ac traction Process for prototype /Vendor approval from RDSO Pre bid meeting Scope of supply Accessories 2.0 Climatic, Environmental & Operating Conditions 3.0 Design and constructional features Salient Design Features: Overall Dimensions, Tank, Marshalling Box,

Core and Winding Insulating Oil Bushings and Terminal Connectors Clearances On Load Tap-Changer Cooling Equipment Corrosion prevention systems and Fasteners 4.0 List of related specifications 5.0 Rating, name plate details and other information 6.0 Inspection and testing Inspection Type tests Routine tests Revalidation of type tests 7.0 Maintenance Manual, tools gauges etc. 8.0 Training of Indian Railway’s personnel 9.0 Packing, Delivery, Commissioning etc. 10.0 Warranty 11.0 Spares, After sales-service & AMC 12.0 Technical Data and drawings to be furnished alongwith tender 13.0 Clause wise conformity, deviations etc. 14.0 Capitalization of transformer losses 15.0 List of appendices in the specifications APPENDIX-A Schedule of Guaranteed Performance, Technical and Other Particulars-

Part- I APPENDIX-B Schedule of Guaranteed Performance, Technical and Other Particulars-

Part- II APPENDIX-C Formula for Calculation of Short Circuit Mechanical Forces APPENDIX-D Capitalization of Transformer Losses APPENDIX-E General Scheme for Traction Power Supply System APPENDIX-F Overall Dimensions of the Transformer APPENDIX-G Format of the Title Sheet to be adopted for Preparation of the Drawings APPENDIX-H Nitrogen Injection Fire Prevention and Extinguishing System for

Oil Filled Transformer APPENDIX-I List of RDSO’s Approved Sources for Parts, Fittings and Accessories

370

RDSO Specification No. TI/SPC/PSI/30TRN/1050 For 30 MVA, 110 /27 kV Traction Transformer

GOVERNMENT OF INDIA: MINISTRY OF RAILWAYS

RESEARCH DESIGNS & STANDARDS ORGANISATION

Specification No. TI/SPC/PSI/30TRN/1050

30MVA, 110 /27kV SINGLE -PHASE

TRACTION TRANSFORMER 1.0 SCOPE 1.1 This specification applies to 30MVA, ONAN, 110 kV/27kV / 50 Hz single-phase traction power transformer for installation in Indian Railway's 25 kV ac traction substations, which may be manned or unattended type. 1.2 Duty of traction power transformer used in 25 kV AC traction. Power is received from the grid network of the State Electricity Board or any other power utility at 110 kV, either at individual traction sub-station (TSS) or at a single point of supply from where it is transmitted through railway's own transmission lines, to the traction substations, with line sectioning facilities provided as required. 25 kV power supply for traction is drawn through a single phase step-down traction transformer. The primary winding of this transformer is connected to any two nominated phases of the incoming three phase lines. On the secondary side, one of the two terminals of the 25kV winding is connected to the traction overhead equipment, while the other is solidly earthed and also connected to the running traction rails. The power is tapped through the secondary winding of the traction transformer and is fed to the over head equipment (OHE) through the associated circuit breakers on the secondary sides, with a separate set of 25 kV circuit breakers called" Feeder Circuit Breakers" for feeding the traction overhead equipment (OHE) lines. General power supply schematic diagram is given in appendix-E. The transformer in one TSS may require to feed the power in the adjacent OHE in case of failure of transformer of other TSS or failure in the OHE. Traction transformers at two to three TSSs shall be operated in parallel by closing the sectioning breaker on 25 kV OHE. 1.3 Process of approval by RDSO and prototype clearance. Vendors applying to RDSO for registration should have ISO- 9000 series certification and meet requirements of STR (schedule of technical requirement) no. TI/STR/014 rev. 0 for which: i) The manufacturer or his authorized representative shall purchase schedule of technical requirement & specification against payment of amounts. ii) After complying with above, manufacturer may apply for vendor approval form No. TIF-0001 against payment of requisite amount. iii) On TIF 0001 being found fit on scrutiny, inspection of the works shall be done by RDSO’s representative to assess the capacity/ capability. The vendor shall offer

371


all facilities to RDSO for conducting the assessment of

manufacturer’s capacity/capability. iv) Based on report of inspection for capacity/ capability assessment, the vendor will be

issued registration form TIF0002 for registration as a developmental source of the equipment.

v) The vendor shall get the design/ drawings approved from RDSO and there after offer the product for prototype testing.

vi) On successful prototype tests, approval shall be accorded in the form no. TIF0003, the developmental status valid for a period of 2 years.

vii) Consideration for upgradation to a regular source will depend on quantity supplied and service performance.

1.4 Pre-bid meeting shall be arranged by the purchaser, with eligible tenderers for the particular requirements of traction transformers to this specification, site conditions, mode of transport, availability of site, erection and commissioning etc. 1.5 Scope of supply, including accessories. The transformer shall be supplied complete with all parts, fittings and accessories necessary for its efficient operation. All such parts, fittings and accessories shall be deemed to be with in the scope of this specification, whether or not specifically mentioned herein. 1.5.1 Conservator tank: It shall be of adequate capacity and complete with supporting bracket or structure, oil filling cap and drain valve of appropriate size, to be indicated in the technical details. The cylindrical portion of the conservator tank shall be of single piece construction without any gasketed joint. Suitable air cell arrangement of high quality material shall be provided in the conservator to ensure that the transformer insulating oil does not come in contact with air. The material of cell shall be coated fabric consisting of – highly resistant polyamide fabric, externally coated with transformer oil resisting coating (chemical), inner coating resisting ozone and weathering. Suitable instructions may please be provided for installation / commissioning and future maintenance of the air cell arrangement. 1.5.2 Oil level gauge: It shall be of magnetic type having a dial gauge with markings corresponding to minimum oil level, maximum oil level and oil level corresponding to oil

temperature of 300C, 450C and 850C. The oil level indicator shall be so designed and mounting that the oil level is clearly visible to an operator standing on the ground. 1.5.3 Silica gel breather: It shall be complete with oil seal and connecting pipes. The connecting pipes shall be secured properly. The container of the silica gel breather shall be of transparent material suitable for outdoor application. The connecting arrangement of the silica gel breather shall be flange type. 1.5.4 Pressure relief device: It shall be designed to operate to release internal pressure at preset value without endangering the equipment or operator and shall be of instantaneous reset type.

372


1.5.5 Filter valves: The valves shall be flanged to seat 40 mm adopter threaded to thread size P 1 - 1/2 for connection to oil filtration plant. The bottom and upper filter valves shall be of appropriate size and suitably baffled to reduce aeration of oil. 1.5.6 Drain valve: It shall be of appropriate size fitted with an oil sampling device. 1.5.7 Equipment earthing terminals: Two earthing terminals shall be provided on the tank for its earthing with the help of 3 mild steel flats, each of size 75 mm x 8 mm. The terminals shall be clearly marked for earthing. 1.5.8 Buchholz relay: It shall be of double float type, with two shut - off valves of appropriate size to be indicated in the technical details, one between the conservator tank and the Buchholz relay and the other between the transformer tank and the Buchholz relay. The relay shall have one alarm contact and one trip contact, none of the contacts being earthed. The contacts shall be of mercury - switch type, electrically independent and wired upto the marshalling box. A testing petcock shall be brought down through a pipe for the purpose of sampling the gas, if any, collected in the Buchholz relay. 1.5.9 Oil temperature indicator (OTI): It shall have one alarm contact, one trip contact and two normally open spare contacts, none of the contacts being earthed. The contacts shall be electrically independent. The OTI shall have a local /remote indication (in control panel) for oil temperature. 1.5.10 Winding temperature indicator (WTI): It shall have one alarm contact, one trip contact and two normally open spare contacts, none of the contacts being earthed. The contacts shall be electrically independent. The WTI shall have a local /remote indication (in control panel) for oil temperature. 1.5.11 Thermometer pockets: A separate thermometer pocket with cap shall be provided on the bell tank for measuring the top oil temperature in the tank. 1.5.12 Nitrogen injection fire prevention and extinguishing system: The complete arrangement of Nitrogen injection fire prevention and extinguishing system has to be provided with the transformer. The requirements of this system have to be as per details given in the Appendix-H. The drawings/documents shall be furnished by the successful tenderer for the approval of RDSO. The system shall be procured from manufacturer having previous supply and performance experiences; credentials shall be furnished along with the tender documents. Clause 10.0 & 11.0 of the specification shall be applicable for warranty, after sale service and AMC respectively for the fire prevention and extinguishing system. 1.5.13 Thermo Siphon Filter System is to be provided for absorbing the moisture present in the insulating oil with the natural convection. The full details for installation and subsequent maintenance have to be furnished to RDSO and the consignee.

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1.5.14 All valves shall be of the double flange type and fitted with suitable blanking plates on the outer face of the exposed flange. 1.5.15 The capillary tubes for temperature indicators shall be able to withstand normal bending. They shall be supported properly without sharp or repeated bends or twists. 1.5.16 All parts, fittings and accessories for the transformer shall be only of those manufacturers approved by RDSO, as given in the Appendix-I. If any item from unlisted manufacturer / source is proposed to be used, it shall be got approved by RDSO. 2.0 Environmental & Operating Conditions 2.1 The transformer shall be suitable for outdoor use in dry arid and also tropical climates and in areas having heavy rainfall, pollution due to industry and coastal environment and severe lightning. The limiting weather conditions, which the equipment has to withstand in service, are indicated below: S. No. Parameters Value 1. Maximum ambient air temperature 50 0 C 2. Minimum ambient air temperature - 2 0 C 3. Maximum relative humidity 100% 4. Annual rainfall Between 1750 mm & 6250 mm 5. Number of thunderstorm days per annum 85 (Max) 6. Number of dust storm days per annum 35 (Max) 7. Number of rainy days per annum 120 (Max) 8. Maximum basic wind pressure 200 kgf/m2 9. Altitude above m.s.l. (max) 1000 m 10. Pollution level Very Heavy as per IEC 815-

1986& IS 13134-1992 2.2 The transformer installation would be subject to vibrations on account of passage of trains on nearby tracks. The amplitudes of these vibrations which occur with rapidly varying time periods in the range of 15 to 70 ms, lie in the range of 30 to 150 microns with instantaneous peaks up to 350 microns. 2.3 The ac electric locomotives are fitted, for conversion of ac to dc, with single- phase bridge- connected silicon rectifiers with smoothing reactor for feeding the dc traction motors. The rectifiers introduce harmonic currents in the 25 kV power supply system. On few of the electrified sections, locomotives fitted with phase controlled asymmetrical thyristor bridge, in place of silicon rectifiers are also in use; these introduce further harmonics in the system. The typical percentages of harmonics present in the traction current with electric locomotives are as follows:

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Harmonics With diode rectifier With thyristor

3 rd (150Hz) 15% 32%

5 th (250Hz) 6% 18%

7th (350Hz) 4% 8%

9 th (450Hz) - 4%

11th (550Hz) - 5%

3.0 Design and constructional features 3.1 Overall dimensions 3.1.1 The overall dimensions of the transformer shall be kept as low as possible and in any case the transformer with all parts / fittings shall not occupy more space than described below ( refer the sketch No. ETI/PSI/SK/340-1 at Appendix – F). 1. Length x Width ( in mm) 8000 x 7000 2. Height of the top most point of primary bushing terminal 7500 mm 3. Height of the topmost point of secondary bushing terminal 5500 mm It shall be possible to transport the transformer in semi knocked down condition to the railway traction sub-station site by rail / road. 3.2 Transformer Tank 3.2.1 The tank for the transformer shall be of bell type construction with flanges on the outside and shall have a flat top. The flanges of the upper and lower tanks shall be jointed by bolts, nuts and suitable plain/spring/belvelle washers. A suitable gasket and metallic stoppers shall be provided between the flanges of upper and lower tank so as to prevent leakage of insulating oil. The tank shall be so designed that the winding and core get fully exposed when the bell tank cover is lifted. 3.2.2 The tank shall be constructed from mild steel of a quality that allows welding any defect/flaw, with a single tier construction so shaped as to reduce welding to the minimum. The welded joints shall be made using the latest welding techniques. The tank shall be adequately strengthened for general rigidity to permit hoisting of the transformer filled with oil by crane. The tank body shall be designed to withstand a vacuum of 760 mm of Hg. 3.2.3 The tank shall be fitted with four lifting pads at the lower and to enable lifting of the transformer filled with oil by means of lifting jacks. The lifting jacks shall be supplied as optional T&P. 3.2.4 The tank shall be fitted with an under carriage and mounted on four bi-directional swiveling type flanged rollers for being rolled on 1676 mm (5' 6") gauge track on which it shall also rest in the final position. The rollers shall be provided with detachable type

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locking arrangement to enable their locking after installing the transformer in the final position to prevent any accidental movement of the transformer. 3.2.5 There shall be at least five inspection covers of suitable size on the tank to enable inspection of the lower portions of bushings and the leads as well as various connections of the on load tap - changer. 3.2.6 The rubberized cork / nitrile gaskets used in the transformer shall conform to IS: 4253 (Part - II). The tank rim should be nitrile rubber cord gasket sitting in semicircular grove. 3.2.7 All valves used in the transformer shall conform to IS: 3639 and shall be of good quality and leak proof. The manufacturer shall ensure that suitable anti - theft measures are provided on these valves so as to prevent theft of oil during transit/service. 3.2.8 Suitable supports shall be provided on the tank for fixing of Aluminum ladder for ease of maintenance at site. Removable aluminum ladder shall be a part of supply. 3.3 Marshalling box 3.3.1 A Vermin proof, weather proof and well ventilated marshalling box made of thickness not less than 2 mm, strengthened with adequate stiffeners, shall be provided on the left hand side of the transformer tank as viewed from the secondary terminals side. It shall have a hinged door with provision for pad locking the door opening outward horizontally. 3.3.2 The marshalling box shall have a sloping roof. The top of the marshalling box shall be at a height of about 2 m from the rail level. 3.3.3 The marshalling box shall house the winding and oil temperature indicators and terminal board .To prevent condensation of moisture in the marshalling box metal clad space heater, controlled by an associated thermostat and switch, shall also be provided. Cable glands shall be provided for the incoming and outgoing cables. 3.3.4 The temperature indicators shall be so mounted that their dials are at a height of not more than 1.6 m from the rail level. Transparent windows of tough acrylic plastic or similar non - fragile transparent material shall be provided on the marshalling box so as to enable reading of the temperature indicators without opening the door of the marshalling box. 3.3.5 All cables from the bushing current transformers, buchholz relay, magnetic oil level gauge, pressure relief device and temperature indicators shall be run through suitable conduits/perforated covered cable trays upto the marshalling box. The cables

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shall be of 1100 V grade, PVC insulated, PVC sheathed, steel wire armoured, stranded copper conductor conforming to IS: 1554 (Part - I). The cables shall be adequately insulated for heat from the tank surface and the sun. 3.3.6 All wiring in the marshalling box shall be clearly identified by lettered / figured ferrules of the interlock type, preferably of yellow colour with black letters /figures. The ac and dc circuits shall be clearly distinguished and well separated from each other. 3.3.7 Suitable legend and schematic diagram plates made of anodized aluminium with black lettering and lines shall be fixed on the inside surface of the marshalling box door. 3.4 Core 3.4.1 The core shall be built from high permeability cold rolled grain oriented silicon steel laminations MOH, Hi-B or ZDKH grade. The flux density in any part of the core and yokes at the principal tapping with primary winding excited at the rated primary voltage and frequency shall not exceed 1.55 T. The successful tenderer / manufacturer shall furnish calculations to prove that this value shall not be exceeded. The core has to be preferably of boltless design to avoid the possibility of local heating. 3.4.2 The laminations for the core shall be free from waves, deformations and signs of rust. Both sides of the laminations shall be coated with suitable insulation capable of withstanding stress relief annealing. In assembling the core, air gaps shall be avoided. Necessary cooling ducts shall be provided, if required, in the core and yoke for heat dissipation. The core-clamping frame shall be provided with the lifting eyes for the purpose of tanking and untanking the core and winding of the transformer. 3.4.3 The core shall be electrically connected to the tank. 3.4.4 Yoke/core clamping bolts if provided shall have adequate threaded length beyond the face of the nuts for tightening at a later stage, if need arises. Each of the core clamping bolts and the core-clamping framework shall be insulated from the core laminations and tested after completion of the core assembly to ensure that they withstand a voltage of 2 kV r.m.s. with respect to core for a duration of 60 s. 3.4.5 The transformer is required to be continuously in service, preferably without requiring any attention from the date of its energisation upto the periodical overhaul (POH) which is generally done after 12 years of service. The need, therefore, for tightening of core clamping bolts should not normally arise before the POH of the transformer. The successful tenderer /manufacturer of the transformer shall take this aspect into account during core assembly /manufacture. 3.4.5 Manufacturer shall, preferably have the core cutting facility in their works and proper monitoring and quality control to avoid any mixing with defective /second grade materials.

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RDSO Specification No. TI/SPC/PSI/30TRN/1050

For 30 MVA, 110 /27 kV Traction Transformer 3.4.6 Manufacturer shall offer the core for inspection and approval by the purchaser during manufacturing stage. The following documents shall also be kept ready during stage inspection of core as a proof towards use of core material as mentioned in SOGP and used in the prototype. a) Invoice of the supplier b) Manufacturer’s test certificate c) Packing list d) Bill of lading e) Bill of entry certificate by customs. 3.5 Windings 3.5.1 The winding shall be of concentric disc construction with primary winding duly intershielded /interleaved for better impulse voltage distribution. The configuration of the windings on each leg after the core shall normally be -LV wdg, HV wdg, regulating wdg (tap), unless approved by RDSO. For any other improved winding design to give better performance, full details with drawing shall be furnished to RDSO for approval. 3.5.2 The windings shall be made of continuous electrolytic copper conductor, paper insulated to class - A insulation. The conductor shall not have any sharp edges which may damage the insulation. 3.5.3 Normally, no joint shall be used in the winding conductor. If a joint becomes inescapable, it shall be brazed with high silver alloy grade BA Cu Ag6 conforming to IS: 2927 or electrically butt - welded. 3.5.4 The ratio of width to thickness of copper conductor used for winding shall be as small as possible but shall not exceed 5:1 so as to avoid tilting of conductors when the windings are subjected to axial and radial forces during short circuit. 3.5.5 A separate tapped winding shall be provided on the primary side for connection of the on load tap - changer. The tapped winding shall be distributed in multi-sections in order to reduce the imbalance in ampere turns to the minimum at any tap position. 3.5.6 The transformer windings shall be designed for the following rated withstand

following rated withstand voltages: S.No. Item Secondary Primary 1. Highest voltage for equipment

Um, kV 52 123

2. Rated short duration powerfrequency

withstand voltage, kV

95 230

3. Rated lightning impulse withstand voltage, kV peak

250 550

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3.5.7 The windings shall be so designed that the transfer of lightning switching surges from primary to secondary windings and vice-versa is kept to the minimum level. 3.5.8 The windings shall be designed to withstand the magnetizing inrush currents due to repeated switching on of the transformer. 3.5.9 The axial pre - compression on the windings shall preferably be double the calculated axial thrust that may be set up under dead short - circuit condition so as to ensure that the windings do not become loose due to frequent short circuits in service. 3.5.10 During short circuits, the stresses actually set up in conductors, spacers, end blocks, clamping rings and such other parts of the transformer shall not exceed one third of the maximum permissible values. 3.5.11 Pre-compressed spacers shall be used between disc shaped coils of the windings to transmit the axial forces generated due to the short circuits. 3.5.12 Wood insulation, if used, on the core and winding shall be seasoned, dried and well compressed and shall have adequate strength. 3.5.13 A uniform shrinkage shall be ensured during the drying of the individual coils or assembly of coils by providing a uniform clamping force with the help of hydraulic jacks or similar such devices. 3.5.14 In order to cater for shrinkages that may occur in service, substantial clamping rings shall be provided at the tops of the windings, being pressed down upon them by means of adjustable pressure screws or oil dash pots or any other suitable device, so as to maintain a constant pressure and obviate the need for any retightening in between successive periodical overhauls. 3.5.15 The coil and core assembly shall be retightened after oil impregnation. The successful tenderer / manufacture shall ensure that there is no further shrinkage of the coil assembly in any additional cycle after the final curing. 3.5.16 The successful tenderer / manufacturer shall furnish details of various stages of drying of coils, coil assembly upto and including oil impregnation and final tightening of the coil assembly. Values of pressure, duration, temperature and degree of vacuum maintained at various stages of drying shall also be indicated. 3.5.17 The core and winding of the transformer have to be dried preferably using vapour phase drying. To ensure the removal of moisture from the transformer the PI value after drying has to be achieved equal to or more than 2 in the manufacturing at the works.

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3.5.18 In order to keep unbalanced axial forces due to non - uniform shrinkage/unequal height of the coils to the minimum wedges of pre - compressed wood or similar such material shall be used. 3.5.19 To prevent displacement of the radial spacers used in the outermost windings, closed slots shall be provided and a vertical locking strip shall be passed through these slots, wherever necessary. 3.5.20 The vertical locking strips and slots of the radial spacers shall be so designed as to withstand the forces generated due to short circuits. 3.5.21 The vertical locking strips and radial shall be made of pre-compressed pressboard conforming to grade PSP: 3052 of DIN: 7733. 3.5.22 To prevent end blocks from shifting, pre - compressed pressboard ring shall be provided in between the two adjacent blocks. Coils clamping rings made of densified wood or mild steel shall be located in position with pressure screws. 3.5.23 Leads from the windings to the terminals, from the tap switch to the tapings of the primary windings and other interconnections shall be properly supported and secured. 3.5.24 The following particulars / documents in respect of the radial spacer blocks (winding blocks), vertical locking strips (axial ribs), end blocks, insulating cylinder, angle rings, paper insulation of the conductor and coil clamping plates used in the manufacture of the windings shall be furnished. 1. Reference to specification and grade of material. 2. Source(s) of supply. 3. Test certificates. 3.6 INSULATING OIL The transformer shall be supplied with new inhibited mineral insulating oil conforming to IS: 12463 and the additional requirements stipulated under clause 6.3.8.9. In addition 10% extra oil by volume shall be supplied in non-returnable barrels. The characteristic of the insulating oil before energisation of the new transformer and during its maintenance and supervision in service shall conform to IS: 1866. 3.7 BUSHINGS AND TERMINAL CONNECTORS 3.7.1 Both the primary and secondary side bushings shall conform to IS: 2099. On the primary side, 145 kV class OIP condenser bushings shall be used. On the secondary side,

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sealed draw rod/ solid stem type oil impregnated paper OIP condenser bushings shall be used. The dimensions of the bushings shall conform to IS: 12676. 3.7.2 The bushings on primary and secondary sides shall be designed for a rated current of 600A and 2500 A respectively. The temperature rise of any part of the bushing shall not

exceed 400 C over an ambient temperature of 500 C while carrying the rated current continuously. 3.7.3 The porcelain housing of bushing shall be of a single piece construction i.e. there shall be no joint in the porcelain. The shed profile shall have a lip at the extremities but free from ribs on the underside so as to avoid accumulation of dust and pollutants and to permit easy cleaning. 3.7.4 The bushings shall have a non- breathing oil expansion chamber. The expansion chamber shall be provided with an oil level indicator, which shall be so designed and dimensioned that oil level is clearly visible from ground level. 3.7.5 A test tap shall be provided for dielectric or power factor measurement for OIP bushings. 3.7.6 The bushings shall be designed for the following insulation level: S.No. Item Secondary Primary

1. Highest voltage for equipment Um, kV

52 145

2. Rated short duration powerfrequency

withstand voltage, kV

95 275

3. Rated lightning impulse withstand voltage, kV peak

250 650

3.7.7 The design and construction of the bushing shall be such that stresses due to expansion and contraction in any part of the bushings shall not lead to its deterioration/ breakage. 3.7.8 The condenser bushings on secondary side shall be free from corona and shall not cause radio interference. 3.7.9 The bushing terminals shall be provided with terminal connectors of bimetallic type and conform to the following:

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1. Primary side: For 110 kV:

Rigid type terminal type connector to suit 28.62 mm overall dia, ACSR conductor (Zebra), size 54/7/3.18 mm,based on RDSO’s standard drawing no. ETI/PSI/P/11010 and shall match with the size of 110 kV side bushing stud on the other side.

2. Secondary side:

For 27 kV: Expansion type terminal connector to suit 50 mm overall diameter Aluminium tubular busbar based on the RDSO's standard drawing No. ETI/PSI/P/11220.

3.7.10 The terminal connectors shall conform to IS: 5561. The design shall be such as to be connected to the equipment terminal stud with a minimum of four 12 mm diameter bolt, nuts, spring and flat washers. The fasteners shall conform to clause 3.12 of this specification. 3.8 BUSHING TYPE CURRENT TRANSFORMERS 3.8.1 The 145 kV and 52 kV bushings on primary and secondary shall be so arranged as to accommodate bushing type current transformers (BCTs) for the biased differential protection of the transformer. The BCTs shall conform to IS: 2705 and meet with the stipulations in clause 5.3 (20) of this specification. 3.8.2 The BCTs shall be so designed as to withstand thermal and mechanical stresses resulting from frequent short circuits experienced by the transformer on which these are fitted. 3.8.3 Apart from the BCTs required for the biased differential protection, a BCT of accuracy class 5 and conforming to IS: 2705, with suitable tappings, shall be mounted inside one of the bushings of the secondary side of the transformer for use with the winding temperature indicator (WTI). 3.8.4 The BCTs and the bushings shall be so mounted that removal of a bushing without disturbing the current transformers, terminals and connections or pipe work is easy and convenient. 3.8.5 The leads from the BCTs shall be terminated in terminal boxes provided on the bushing turrets. Suitable links shall be provided in the terminal boxes for shorting the secondary terminals of the BCTs, when not connected to the external measuring circuits. 3.8.6 The leads from the secondary winding of the BCTs terminated in the terminal box on the bushing turret upto the marshalling box shall be of 1100 V grade, PVC insulated,

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PVC sheathed, armoured, stranded copper cable of cross-section not less than 4 mm2 to IS: 1554 (Part-I). 3.8.7 Cable glands of proper size shall be provided in the terminal boxes to lead in/lead out the cables. 3.9 CLEARANCES The relative orientation in space of the bushings fitted with terminal connectors, the main tank, radiators, conservator, pressure relief device, oil piping and other parts when mounted on the transformer shall be such that the various clearances in air from bushing live parts shall not be less than the appropriate values given hereunder: 1. Highest voltage for equipment Um, kV 52 123 2. Minimum clearance, mm 500 1100 The same distance shall apply for clearance phase - to - earth including oil piping work, conservator, pressure relief device and such other parts), phase to phase, and towards terminals of a lower voltage winding. 3.10 ON LOAD TAP-CHANGER On load tap changer shall be sourced from reputed manufacturer and it should be type tested as per relevant IEC 60214 and test methods shall be in conformance to the procedures indicated in IEC 60214. The OLTC shall have proven field performance. Voltage shall be substantially constant at the untapped windings (secondary windings) and variable at the tapped winding (primary winding). The category of regulation applied shall be constant –flux variable voltage type (CFVV). The 17 taps on-load tap changer shall be in tank type, divertor - selector type, single –phase enclosure type, installed in a separated oil tank. It shall have range from 118.75 kV to 98.75 kV (+ 7 taps to - 9 taps) with per tap voltage of 1.25 kV. The voltage ratio shall be checked according to the guaranteed figures and the tolerances stipulated in the standards. The principal tap shall be on tap no. 8. There shall be 7 Taps for higher input voltage and 9 taps for lower input voltage variation. On load tap changer shall have maximum rated through current of 600 A to meet the normal rated load as well as non cumulative over load at all the taps as mentioned in clause 5.3. The OLTC shall have BIL rating corresponding to 145 kV class and short circuit withstand current as per relevant IEC standard but not less than 8 kA for 3 seconds. The OLTC must be designed to ensure to the prescribed and expected harmonic levels of the system. The design of transition resistance and contacts shall be adequately taken care.

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The OLTCs should also be suitable for paralleling of three transformer of different loading. The loading pattern will be furnished during ordering stage. The full technical description shall be given as regards power and auxiliary circuits; periodicity for checking and overhauling the power circuit shall be indicated in the transformer maintenance manual. 3.10.1 The transformer shall be provided with local OLTC control cabinet and RTCC panel. The tap changer shall have the following characteristics: i The power circuit of the on-load tap changer shall be connected to the primary

windings and shall enable the required voltage variations. ii The oil volume of the on -load tap changer unit must be separated from the tank

for core and winding oil. iii 50 000 operations without any attention. iv Motor operated for local as well as remote operation and external handle for

manual hand operation. v Tap position indicators vi Commutation current compatible with the overload current of transformer.

Necessary provisions be available to ensure that OLTC will not operate during overloading.

vii Diverter switches shall be designed for high speed operation and shall be interlocked to ensure that there is no possibility of an operation stopping in mid-position. Arcing contacts shall be of tungsten alloy material.

viii Operating mechanism for on load tap changer shall be designed to go through one step of tap change per command. Subsequent tap changes shall be initiated only by a new or repeat command.

ix Local OLTC control cabinet shall be mounted on the tank in accessible position. It should be adequately ventilated and provided with anti- condensation metal clad heaters. All contactors relay coils and other parts shall be protected against corrosion, deterioration due to condensation, fungi etc.

x Limit switches shall be provided to prevent overrunning of the mechanism and shall be directly connected in the circuit of the operating motor. In addition, a mechanical stop shall be provided to prevent over-running of the mechanism under any condition.

xi A five-digit non resetable type counter shall be fitted to the tap changing equipment to indicate the number of operations completed.

xii It shall not be possible for any two controls to be in operation at the same time. xiii A suitable protection relay shall be connected on the oil pipe between the on- load

tap changer and the expansion vessel. xiv Devices for ease of extraction for maintenance purpose.

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3.10.2 OLTC Control of Transformers The on load tap changer of the single-phase transformer shall be suitable for local and remote control. It shall be provided with necessary interface for its remote control through SCADA. The control feature shall provide the following: i) Local Electrical Control a. ‘Local-Remote’ selector switch mounted in the local OLTC control cabinet shall

switch control the load tap changers as follows: (i)When the selector switch is in ‘local’ position, it shall be possible to operate the ‘raise-lower’ control switches specified below. Remote control of the raise- lower functions shall be prevented. (ii) When the selector switch is in ‘remote’ position the local OLTC control cabinet mounted ‘raise-lower’ switch specified below shall be in-operative. Remote control of the raise/lower function shall be possible from the remote control panel.

b. A ‘raise-lower’ control switch/push button shall be provided in the local OLTC control cabinet. This switch shall be operative only when ‘local remote’ selector switch is in ‘local’ position.

c. An OFF-ON tap changer control switch shall be provided in the local OLTC control cabinet of the transformer. The tap changer shall be in-operative in the OFF position.

ii) Manual Control The cranking device for manual operation of the OLTC gear shall be removable and suitable for operation by a man standing at ground level. The mechanism shall be complete with the following: a. Mechanical tap position indicators that shall be clearly visible from near the

transformer. b. A mechanical operation counter. c. Mechanical stops to prevent over cranking of the mechanism beyond the extreme

tap positions. d. The manual control considered as back up to the motor operated load tap changer

operation. The manual operating mechanism shall be labelled to show the direction of operation for raising / lowering.

3.10.3 Remote Tap Changer Control Panel The contractor shall supply a Remote Tap changer control (RTCC) panel suitable for remote operation of on load tap changing gear. The RTCC panel shall house actuating switch for electrical raise/lower control, tap position indicator, signal lamps for “Tap change in progress” and “Tap changer out of step” and all other auxiliary devices for remote electrical control of the OLTC.

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3.10.4 Voltage Regulation through Parallel Operation and AVR (Automatic voltage

regulator) The traction power transformers at the traction sub stations shall be able to be operated in Parallel. The approximate distance between such traction sub stations may be in range of 10 - 20 kms. AVR (Automatic voltage regulator) shall be provided to maintain the voltage in the desired range and also to ensure the desired Transformers are at the same tapping point. It should have both automatic and manual provisions. It should be possible to operate the OLTC through remote and the required control panel shall be provided. The servo –mechanism settings shall be designed and executed to avoid too many actuation .The manufacturers shall provide technical and directional diagrams. The AVR shall have following features/characteristics.

• Automatic voltage control shall be initiated by a voltage-regulating relay of

field proven make and suitable mounting. The AVR shall easily be extendable with functions for monitoring and cooling of transformers.

• The nominal reference voltage derived from a circuit mounted 1 phase

Voltage transformer (VT)

• The AVR shall be microprocessor based numerical relay with illuminated graphical LCD display

• The relay shall have 3 independent selectable reference voltage levels

• The following methods for voltage compensation shall be

adjustable a) Active Current (Line Drop Compensation)

b) Reactive current (Z-Compensation)

• The bandwith shall be adjustable between 0.5% to 9.0% in steps of 0.1% of the desired voltage level

• The time delay for regulation shall be selectable within limits of 1 - 600

seconds. Either linear or integral time behaviour shall be possible. Separate setting of delay time T2 for deviation above 2 taps difference is required.

• The relay shall be equipped with undervoltage and overcurrent

blocking facility which shall make the control inoperative if voltage falls below the respond threshold and can be adjusted by percentage value. Overvoltage detection shall send periodic impuls signals without regard of the adjusted time delay.

• The standard LDC display of the relay shall have facility to indicate the

following integrated features:

a) display of OLTC tap position b) Measurement Voltage

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c) Reference Voltage d) Actual deviation (bandwidth) e) Load current, Active power, Reactive power, Apparent power, phase

angle, Power factor, Frequency. • The unit shall have the facility to compensate the VT and CT- errors.

• To provide easy and fast installation the AVR shall be equipped with

NORMSET functionality.

• The unit shall be equipped with measurement recorder for voltage, current and tap position. Those data as well as power P, Q, S and Cos phi shall be stored up to one year. The measurement is adjustable by 1, 2, 4, 10, 20 or 40 seconds. A separate event recorder for over- and undervoltage records all measured values every 300ms. The recorded values shall be presented in graphical format on the device and on the connected computer.

• The Unit shall have facility to make selection of Auto / Manual and Local /

Remote either directly on the device or via remote signal.

• The Unit shall have different LEDs to indicate transformer protection alarms (U<, U>, I<)

• The Unit shall in addition be equipped with at least 4 freely programmable LEDs

in different colors to indicate different Operations / Alarm / Faults conditions.

• The unit shall be able to take Tap position via BCD input (digital signal) from OLTC

• without any additional transducers.

• The Unit shall be equipped with at least 12 free programmable binary in- and outputs

• The Unit shall have facility to monitor and control the following transformer parameters: a) Life time consumption of transformer b) Recording of Hot spot temperature c) Measurement and recording of Oil temperature

• The Unit shall be delivered with WIN-based visualisation software to make the parameter settings of the device and it shall also be possible to do the parameter setting through keyboard of relay.

• The Unit shall be able to communicate with higher level Computer Control

System either via fibre optical serial interface RS485 or RS232 and protocol IEC60870-5-103

• The Unit shall be capable to be easily extended with additional functionalities after several years in operation. This contains the extension of hardware for additional

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signals and the extension of functionalities (e.g. parallel operation of transformers) without replacement of the existing device. 3.10.5 Auxiliary power supply and control supply Auxiliary supply of single phase AC 240 Volts (varying from 180 to 270 Volts) and control supply of DC at 110 volts (varying from 77 to 121 Volts) are available at the traction sub station for OLTC. 3.11 COOLING EQUIPMENT 3.11.1 The transformer shall be designed for ONAN type of cooling. 3.11.2 The radiators shall consist of a pressed steel plate assembly formed into elliptical oil channels (as per IEEMA (Indian Electrical & Electronic Manufactures Association)'s standard) or a series of separate elliptical tubes. The radiators shall be designed in such a manner that the temperature - rise limits specified under Clause 5.3 (13) of this specification are not exceeded. Collector/ header pipes in the radiators are to be ERW pipes of thickness 4.5 mm. The external painting of the radiator has to be as per clause 3.13 of this specification. The radiators & accessories should be given external paint coats - first coat of epoxy zinc rich (having minimum 83% metallic zinc) primer (50 micron thickness), intermediate coat of epoxy chemical and corrosion resistant High Build Epoxy Intermediate paint (100 micron thickness) and final coat of Glossy Aliphatic Acrylic Polyurethane Coating paint (50 micron thickness). The total dry film thickness of the paints shall be minimum 200 micron. The shade of paint shall be gray as shade 631 of IS: 5. 3.11.3 The radiators shall be removable (after isolating the same from the main tank) to facilitate transportation of the transformer. A drain plug of size 19 mm and an air - release plug of size 19 mm shall be provided at the bottom and at the top of each radiator bank for draining and filling of oil respectively. Each radiator bank shall also be provided with shut - off valves of size 80 mm shall be used between tank and headers. 3.11.4 The radiators shall preferably be supported directly on the transformer tank. Each radiator bank shall be fitted with two hooks, one at the centre for lifting the radiator and the other for tying the unit in service. 3.12 FASTENERS All fasteners of 12 mm diameter and less exposed to atmosphere shall be of stainless steel and those above 12 mm diameter shall preferably be of stainless steel or mild steel

hot dip galvanized to 610 g / m2 of zinc. The material of the stainless steel fasteners shall conform to IS: 1570 (Part- V). Grade 04Cr17Ni12Mo2

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3.13 PAINTING 3.13.1 Shot blasting / sand blasting shall be done on the transformer tank to remove all scales, rust and other residue before applying the paint inside the tank. All steel surfaces which are in contact with insulating oil shall be painted with heat resistant oil - insoluble insulating varnish. 3.13.2 All steel surfaces exposed to weather shall be descaled /grit blasted. The epoxy and polyurethane protective paints as per ISO/EN 12944 have to be provided for proper protection against corrosive and coastal environments and give life of approx. 12-15 years. All the external surfaces of the Transformer shall be given first coat of epoxy zinc rich (having minimum 83% metallic zinc) primer (50 micron thickness), intermediate coat of epoxy chemical and corrosion resistant High Build Epoxy Intermediate paint (100 micron thickness) and final coat of Glossy Aliphatic Acrylic Polyurethane Coating paint (50 micron thickness). The total dry film thickness of the paints shall be minimum 200 micron. The shade of paint shall be gray as shade 631 of IS: 5. Same paints have to be applied at damaged surfaces, if any, at site during erection /commissioning of the transformer. One final coat of polyurethane paint has to be applied to ensure proper smoothness and finish. 4.0 LIST OF RELATED SPECIFICATION 4.1 In the preparation of this specification, assistance has been derived from the following standards and codes of practices (latest version), and Indian Electricity Rules wherever applicable. 1 IS:5 Colours for ready mixed paints and enamels. 2 IS/EN 12944 Protective Paint Systems 3 IS: 12463 New insulating oils. 4 IS:1554 (part-I) PVC insulated (Heavy duty) electric cables for working

voltages up to and including 1100 volts. 5 IS:1570 (Part-V) Stainless and heat resisting steels. 6 IS:1576 Solid pressboard for electrical purposes. 7 IS:1866 Code of practice for maintenance and supervision of

mineral insulating oil in equipment. 8 IS:2026 Power transformers. 9 IS:2099 Bushing for alternating voltages above 1000 volts. 10 IS:2705 Current transformers. 11 IS:2927 Brazing alloys. 12 IS:3024 Electrical steel sheets (oriented). 13 IS:3637 Gas operated relays. 14 IS:3639 Fittings and accessories for power transformers. 15 IS:4253 Cork and rubber. 16 IS:5561 Electrical power connectors.

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17 IS:5621 Hollow insulators for use in electrical equipment. 18 IS:5728 Guide for shot- circuit calculations. 19 IS:6209 Methods for partial discharge measurements. 20 IS:6600 Guide for loading of oil - immersed transformers. 21 IS:8468 On load tap changers. 22 IS:10028 Code of practice for selection installation and maintenance of

transformers. 23 IS:10593 Method of evaluating the analysis of gases in oil- filled electrical

equipment in service. 24 IS:12676 Oil impregnatedpaperinsulatedcondenserbushings- dimensions and

requirements. 25 IEC:76 Power transformers. 26 IEC:137 Bushings for alternating voltages above 1000 volts. 27 IEC:185 Current transformers. 28 IEC 60214 On load tap changers 29 DIN:7733 Laminated products, pressboard for electrical engineering, types, 4.2 In case of any conflict between the contents of the above specifications and this specification, the later shall prevail. 4.3 Any deviation from this specification, proposed by the tenderer, calculated to improve the performance, utility and efficiency of the equipment, will be given due consideration provided full particulars of the deviations with justification therefore, are furnished. In such a case, the tenderer shall quote according to this specification and the deviations, if any, proposed by him shall be quoted as an alternative/ alternatives. 5.0 Rating, name-plate details and other information 5.1 The rating plate shall indicate the ratings of the transformer, the connection diagram of the windings, the particulars of the bushing current transformers and other details as per IS: 2026. The rating plate shall be both in English and Hindi version. 5.2 The short- circuit apparent power at the transformer location for various system voltages is as under:

Highest system voltage kVrms)

Three Phase Short - circuit apparent power

(MVA) 123 10000

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5.3 Particulars of the System The rating and general data of the transformer shall be as follows: 1. Type : ONAN cooled, single phase, step-down power transformer, double limb wound, core -type for outdoor installation. 2. Windings : Uniformly insulated concentric disc duly interleaved / intershielded. 3. Rated frequency, Hz : 50 +/-3% 4. Rated primary voltage Un, kV 5. Highest Primary system voltage Um, kV

: 110 : 123

(However there may be voltage variation from 90 to 121 kV)

6. Rated secondary voltage (at no-load), kV

: 27

7. Rated power, MVA : 30 8. Rated current at the principal tapping 1. Rated primary current, A : 273 2. Rated secondary current, A : 1111 9. Maximum value of Percentage Impedance at the principle and extreme tap positions at 30 MVA base.

(16 +/- 0.5)% at principal tap & between 15 to 17 % at extreme tap position (Absolute value of transformer impedance at all the taps shall be within 15 to 17 % of the base value at principal tap)

11. Non - cumulative over load capacity after the

transformer has reached steady temperature on continuous operation at rated load( i.e. at rated power)

1. 150% rated load for 15 min 2. 200% rated load for 5 min

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Note: Non cumulative power load means overload which occur at sufficient interval of time apart such that the temperature rise limits, both of oil and winding do not exceed the values specified in clause 5.3 (13) of this specification .The interval of time between two successive non cumulative overloads shall not be less than 3 hours. 11. Polarity : Subtractive 12. Tappings (On load tap changer)

: A separate tapped winding on the primary winding to give rated secondary voltage for variation in primary voltage from 118.75 kV to 98.75 kV, in steps of 1.25 kV each. 7 Taps for higher input voltage and 9 taps for lower input voltage variation. (However the voltage variation on primary may be from 90 to 121 kV) OLTC shall be of 145 kV voltage class and shall have maximum rated through current not less than 600 A, short circuit withstand current not less than 8 kA for 3 seconds.

13. Temperature rise The temperature rise over an ambient

temperature of 500C both at rated and overload conditions shall not exceed the value indicated below:

1. Winding: 50 0C at rated load, and 60 0C for overloads as specified in Clause 5.1(10) (temperature measured by resistance method).

2.Top oil:400C(temperature rise measured by thermometer).

3. Current carrying parts in air: 40 0C (temperature rise measured by thermometer).

14. Maximum permissible losses at rated frequency, voltage, current and at the principal tapping

1. Max. No-load loss (kW) 15 2. Max Load loss (kW) 117 3. Total loss (kW) 132

15.

Ability to withstand short circuit 1. Thermal ability : 5 s 2. Dynamic ability : 0.25 s

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For 30 MVA, 110 /27 kV Traction Transformer 16. Flux density at rated voltage and

frequency at principal tapping (Flux density has not to exceed 1.90 tesla at any of the taps at extreme voltage condition)

: Shall not exceed 1.55 tesla

17. Current density in the windings at : rated current

Shall preferably not exceed 2.5

A/mm2

18. Acoustic sound level when energized at rated voltage and at no-load

: Not more than 75 dB at a distance of one meter.

19. Bushings:

Item Secondary Primary

1. Type OIP condenser OIP condenser 2. Highest voltage for equipment

Um, kV

52 145

3. Rated current, A 2500 600 4. Minimum creepage distance in air ,

mm 1600 3625

20. Bushing type current transformers for differential protection of transformer:

Item Secondary Primary 1. Highest voltage for equipment

Um, kV 52 123

2. CT ratio 3000/5 600/5

3. Frequency , Hz 50 +/- 3 %

4. Class of accuracy as per IS PS 2705 (Part IV)

5. Minimum knee -point emf , V 360 175

6. Maximum excitation current at

knee - point voltage , A 0.100 0.75

7. Maximum resistance of the secondary winding , ohm 0.9 0.25

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6.0 Inspection and Testing 6.1 Inspection The inspection of the transformer shall be carried out by an authorized representative of the Indian Railways as per purchase order. Prototype inspection shall be done by RDSO. After successful completion of all the type and routine tests as per this specification, prototype approval shall be issued by RDSO. After approval of prototype, inspection and routine tests on the balance quantity shall be done by the authorized representative of the Indian Railways as per purchase order. 6.1.1 Only after all the designs and drawings have been approved and clearance given to this effect by RDSO, the manufacturer shall take up manufacture of the prototype for inspection/testing by RDSO. It is to be clearly understood that any changes to be done on the prototype as required by RDSO, the same shall be done expeditiously. 6.1.2 Prior to giving a call for inspection and testing of the prototype, the successful tenderer/manufacturer shall submit a detailed test schedule consisting of test procedures, schematic circuit diagrams, items/parameters to be checked and values required as per specification for each of the tests and the number of days required to complete all the tests at one stretch. The schedule shall also indicate the venue of each of the tests. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the DG/TI/RDSO, Lucknow reserves the right to conduct any additional test(s), besides those specified herein, on any equipment/item so as to test the equipment/item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer/manufacturer and the representative of the DG/TI/RDSO, Lucknow during the process of testing as regards the procedure for type tests and/or the interpretation and acceptability of the results of type tests, it shall be brought to the notice of the DG/TI/RDSO, Lucknow as the case may be whose decision shall be final and binding. Only after the prototype of the equipment is manufactured and ready in all respects, shall the successful tenderer/manufacturer give the actual call for the inspection and testing with at least 15 days notice for the purpose. 6.1.3 In the event of the tests not being carried through to completion at one stretch for any reason attributable to the successful tenderer/manufacturer and it is required for the representative of the DG/TI/RDSO, Lucknow to go again or more number of times to the works of the successful tenderer/manufacturer or to any NABL approved testing house/laboratory where tests are being done for continuing and/or completing the tests on the prototype(s) of the equipment, the successful tenderer/manufacturer shall reimburse to the DG/TI/RDSO the cost for the representative(s) having to visit the works or other place(s) for the tests more than once. The cost as claimed by the DG(TI)/RDSO, Lucknow shall be paid through a Demand Draft to the concerned Accounts Officer of the DG/TI/RDSO Lucknow as shall be advised to the successful tenderer/manufacturer.

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For 30 MVA, 110 /27 kV Traction Transformer 6.1.4 The tests shall be conducted on the prototype of the transformer at the works of the manufacturer or at any NABL approved testing house or laboratory in the presence of DG (TI)/RDSO, Lucknow or his authorised representative. The prototype shall be complete in all respects, including the terminal connectors as would be supplied if it had passed the tests.The tests shall be conducted to the governing specification and as modified or amplified herein. 6.1.5 For tests conducted in the laboratories of Central Power Research Institute, Bhopal/ Bangalore, Electrical Research Development Association, Vadodara or any such testing house or laboratory, a certificate to the effect that the equipment has passed the tests as per specification shall be obtained by the manufacturer and submitted to the DG (TI), RDSO, Lucknow. Full details of the tests and test parameters shall be furnished along with the test reports. 6.1.6 The type tests may, at the discretion of the DG (TI)/RDSO, also be carried out on one or more of the following equipments: - Equipment completely manufactured at the manufacturer's works overseas. - Equipment assembled in India using CKD if the tenderers so desire. - Equipment indigenized by the Indian Manufacturer (stages/indigenization levels

at which the type tests will require to be carried out, will be settled mutually between the Indian manufacturer and the Railways, in consultation with the collaborator.)

6.1.7 All the testing /measuring equipments shall be duly calibrated by a master traceable to National Standards. 6.1.8 Irrespective of the equipment being a standard/proven item of the manufacturer for which type tests have already been conducted and the test results are available, the type tests shall nevertheless, be conducted for the procurement against this specification. The type tests and the routine tests to be carried out on the equipment, as part of above inspection, are given below. 6.1.9 The type tests shall be carried out in accordance with TIQ 2001 Ver.1, Quality Plan For Traction Power Transformer Prototype testing & with the relevant standards as modified or amplified by the specification where ever applicable, at the works of the successful tenderer /manufacturer, or at a reputed testing laboratory in the presence of the authorized representative of the DG/TI/RDSO, Lucknow. Successful tenderer shall furnish the type and routine test schedule based on the RDSO specification for approval before commencement of tests. 6.2 Tests during manufacture Though the tests described below shall form a part of the type tests, the manufacture shall carry out these tests on each and every unit during the process of manufacture and submit the test reports to the Purchaser's Inspector deputed for witnessing the routine tests:

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1. Oil leakage test. 2. Vacuum test. 3. Pressure test. 4. Insulation test for core bolts. 5. Test for pressure relief device.

6.2.1 Oil leakage test: The transformer with its radiators, conservator tank and other parts, fittings and accessories completely assembled shall be tested for oil leakage by being filled with oil conforming to IS: 12463 at the ambient temperature and subjected to a pressure corresponding to twice the normal static oil head or to the normal static oil

head plus 35 kN/m2 (0.35 kgf/cm2), whichever is lower, the static oil head being measured at the base of the tank. This pressure shall be maintained for a period of not less than 12 h, during which time no leakage shall occur. 6.2.2 Vacuum test: The transformer tank only shall be tested at a vacuum of 3.33

kN/m2 (0.0333 kgf/cm2) for 60 min. The permanent deflection of flat plates after release of vacuum shall not exceed the values specified below:

Horizontal length of flat plate Permanent deflection, mm Upto and including 750 mm 5.0 751 mm to 1250 mm 6.5 1251mm to 1750 mm 8.0 1751 mm to 2000 mm 9.5 2001 mm to 2250 mm 11.0 2251 mm to 2500 mm 12.5 2501 mm to 3000 mm 16.0 Above 3000 mm 19.0

6.2.3 Pressure test: Every transformer tank, radiator and conservator tank shall be subjected to an air pressure corresponding to twice the normal static head of oil or to the

normal static oil head pressure plus 35 kN/m2 (0.35 kgf/cm2), which ever is lower, as measured at the base of the tank. The pressure shall remain constant for 1 h to indicate that there is no leakage. 6.2.4 Insulation test for core bolts: This test shall be done as described in Clause 3.4.4 of this specification. 6.2.5 Test for pressure relief device: Every pressure relief device shall be subjected to gradually increasing oil pressure. It shall operate before the pressure reaches the test pressure specified in Clause 6.2.3 hereof and the value at which it has operated shall be recorded. 6.2.6 The purchaser may, if he so desires, carry out any checks or tests on the quality of manufacture at any stage during coil winding, drying of coils, assembly of coils on core and method of drying, vacuum impregnation, tightness of core clamping bolts, adequacy of pressure on coils or any other aspects as deemed so as to ensure that proper quality is maintained.

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For 30 MVA, 110 /27 kV Traction Transformer 6.3.1 Type tests The type tests shall be carried out on the prototype transformer at the works of the successful tenderer/manufacturer or at any NABL approved testing house or laboratory in the presence of the representative of the purchaser /DG (TI), RDSO, Lucknow, and in accordance with the relevant specifications and as altered, amended or supplemented by this specification. The following shall constitute the type tests:

1. Temperature - rise test. 2. Lightning impulse test. 3. Test with lightning impulse, chopped on the tail. 4. Short - circuit test. 5. Measurement of acoustic sound level. 6. Measurement of partial discharge quantity. 7. Measurement of harmonics of no - load current.

6.3.1 Temperature - rise test 6.3.1.1 The temperature - rise test shall be done with the tap changer on the lowest tap position (- 9 tap) with IS: 2026 ( Part II) except as modified hereunder:

1. At rated load. 2. At 150% rated load for 15 min after continuous operation at rated load for

1 h. 3. At 200% rated load for 5 min after continuous operation at rated load for

1 h. The tests shall be done continuously without any power supply interruption. In case interruptions of power supply do take place for some reason, then the entire test shall be repeated after steady state conditions are attained. 6.3.1.2 The points to be ensured during the temperature - rise test shall be:

1. The ambient temperature shall be measured using alcohol in glass thermometers only.

2. The winding temperature shall be determined by the resistance method only. 3. The temperature of the top oil shall be measured by an alcohol in

glass thermometer placed in an oil- filled thermometer pocket. 4. The average oil temperature shall be calculated as the difference between

the top oil temperature and half the temperature drop in the cooling equipment (radiators).

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5. The temperature of the hot - spot in the winding shall be the sum of the temperature of the top oil and 1.1 times the temperature rise of the winding above the average oil temperature.

6.3.1.3 The test shall be carried out as described below: 6.3.1.3.1 100% load 1. A quantum of power equal to the sum of the measured losses viz. No- load loss

and load losses measured at minus 9 tap position, corrected to 750C plus 10 % of such sum shall be fed to the primary winding of the transformer with the secondary windings short- circuited.

2. The power so fed to the transformer shall be continuously maintained till such time as the steady state temperature is reached i.e. the top oil temperature rise does not

vary by more than 10 C during four consecutive hourly readings. 3. On attaining the steady state temperature, the current in the primary winding of the

transformer shall be brought to the rated current which shall be maintained for 1 h. At the end of the period the power supply to the transformer shall be switched off and the time of switching off recorded.

4. The measurement of hot resistance shall commence as soon, as is possible after switching off. The first reading of the resistance shall be taken before the expiry of 90 s from the instant of switching off and the first ten readings shall be taken at intervals of 15 s apart. Thereafter, another ten readings shall be taken at intervals of 30 s apart.

5. The time at which each of the resistance values is read shall also be recorded. 6. The temperature of the ambient, top oil, the top and bottom radiator header oils

shall also be recorded at half - hourly intervals through out the test starting from the instant power supply is switched on to commence the test till it is switched off.

7. The WTI and OTI readings shall also be recorded at half-hourly intervals right from the instant the power supply is switched on to commence the test till it is switched off.

8. After power supply is switched off, the readings of OTI and WTI shall be recorded at intervals of 1 min apart for 30 min.

6.3.1.3.2 150% load 1. After completion of the test at 100 % load, the transformer shall be fed with

power, which shall be a value so as to cause circulation of the rated current in the primary winding with secondary windings short - circuited. This current shall be circulated for 1 h.

2. The current shall thereafter be increased to 150 % of the rated current and maintained for a period of 15 min. At the end of the 15 min period, the power supply shall be switched off and the time of switching off shall be recorded.

3. Thereafter the readings as indicated in Clauses 6.3.1.3.1(4 to 8) shall be recorded.

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For 30 MVA, 110 /27 kV Traction Transformer 4. The temperature of ambient, top oil, the top and bottom radiator header oils and

the temperatures indicated by OTI and WTI shall also be recorded at the time of switching on 150% load as well as at the time of switching off the power supply.

6.3.1.3.3 200% load

1. After completion of the test at 150 % load, the transformer shall be fed with power, which shall be a value so as to cause circulation of the rated current in the primary winding with secondary windings short - circuited. This current shall be circulated for 1 h.

2. The current shall thereafter be increased to 200% of the rated current and maintained for a period of 5 min. At the end of the 5 min period, the power supply shall be switched off and the time of switching off shall be recorded.

3. Thereafter the readings as indicated in Clauses 6.3.1.3.1 (4 to 8) shall be recorded.

4. The temperature of ambient, top oil, the top and bottom radiator header oils and the temperatures indicated by OTI and WTI shall also be recorded at the time of switching on 200% load as well as at the time of switching off the power supply.

6.3.1.4 Determination of thermal time constant of the windings: The thermal time

constant of the primary and secondary windings under both rated and overloads shall be verified during the temperature - rise tests.

6.3.1.5 The temperature rise of the oil, windings and current carrying parts in air under

both the overloads conditions stipulated in Clauses 6.3.1.3.2 and 6.3.1.3.3 above shall not exceed the values stipulated in Clause 5.3 (13) of this specification. The

winding hot - spot temperature under the overload conditions shall not exceed 1150

C. 6.3.1.6 Testing and calibration of the temperature indicators: The functioning of the

OTI and WTI shall be verified during the tests described above. Both the OTI and WTI shall be recalibrated, if necessary, to reflect the respective temperatures correctly. In particular, the reading of the WTI shall be same as the calculated value of the hot - spot temperature of the winding.

6.3.1.7 Determination of the thermal time constant of the WTI: The thermal time

constant of the WTI shall be determined for comparison with the thermal time constant of the winding of the transformer with respect to the transformer oil. For this purpose, the indications of the WTI and the OTI shall be recorded every 1 or 2 min during the first 1 h from the instant the transformer is loaded. From the slope of the curve plotted with the time on the X - axis and the difference between the readings of the WTI and OTI at the particular time on the Y - axis, the thermal time constant of the WTI shall be determined. This value shall not vary appreciably from the thermal time constant of the winding as calculated theoretically and as ascertained from the slope of the cooling curves.

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For 30 MVA, 110 /27 kV Traction Transformer 6.3.1.8 The Dissolved Gas Analysis shall be conducted on the sample of oil drawn from

the transformer tank before & after temperature rise test. 6.3.2 Lightning impulse test 6.3.2.1 This test shall be done in accordance with IS: 2026 (Part III). Each of the

terminals of the primary and secondary windings shall be tested with the following voltages:

1. Highest voltage for equipment, Um, kV 52 123 2. Lightning impulse withstand voltage, kV peak 250 550

6.3.3 Test with lightning impulse, chopped on the tail

This test shall be done in accordance with IS: 2026 (Part III) with the appropriate test voltage stipulated in Clause 6.3.2.1 above.

6.3.4 Short - circuit test 6.3.4.1 The short- circuit test shall be conducted in accordance with IS: 2026 (Part I) with

the following schedule: 6.3.4.2 Prior to commencement of the test, the following measurements/ tests shall be

made: 1. Insulation resistance of the windings with respect to the earth and between the windings. 2. No- load current. 3. No- load loss. 4. Resistance of the windings. 5. Percentage impedance voltages. 6. Load loss. 7. Voltage ratio. 8. Di- electric tests comprising:

1) Separate - source voltage withstand test, and 2) Induced over-voltage withstand test.

9. Recording of recurrent surge oscillogram (RSO) at the highest (+ 7 tap), lowest (- 9 tap) and principal tapping.

6.3.4.3 The test shall preferably be done by closing the breaker on the secondary side after energizing the primary winding at its rated voltage. 6.3.4.4 The transformer shall be subjected to a total of seven shots in the following sequence:

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1 st shot - Symmetrical current at the highest tap (+ 7 tap). 2 nd shot - Asymmetrical current at the highest tap (+ 7 tap). 3 rd shot - Asymmetrical current at the principal tap. 4 th shot - Symmetrical current at the principal tap. 5 th shot - Symmetrical current at the lowest tap (- 9 tap). 6 th shot - Asymmetrical current at the lowest tap (- 9 tap). 7 th shot - Symmetrical current at the lowest tap (- 9 tap).

6.3.4.5 The operation of each shot shall be 0.25 s. 6.3.4.6 Measurements shall be done after each shot for the following:

1. Percentage impedance voltage. 2. No-load current. 3. No- load loss.

6.3.4.7 Further testing and inspection of the transformer subjected to the short-circuit test

shall be carried out as per IS: 2026 (Part-I) with the modification that:

1. The dielectric routine tests shall be at 100% of the original test value. 2. The percentage impedance voltages measured after the short-circuit test

shall not vary by more than 2% from those measured before the short- circuit test.

6.3.4.8 On completion of the short-circuit test the transformer shall be untanked for

inspection of the core and windings. In case the inspection of the core and windings do not reveal any apparent defects and the results of the short – circuit test, the values of percentage impedance voltages as also the results of the routine tests done after the short- circuit test are in order, the transformer shall be deemed to have passed the short-circuit test. If any of the results of the tests are not in order or the inspection of core and windings reveals any defect, then the transformer shall necessarily have to be dismantled completely for detailed inspection.

6.3.4.9 Frequency response analysis (FRA) of the prototype transformer is to be

preferably carried out before and after the short circuit test to judge the healthiness of the transformer after short circuit and this can be kept as reference for future. Similar Frequency response analysis (FRA) records for other transformer units may preferably be furnished to be used for future reference.

6.3.5 Measurement of acoustic sound level

Measurement of acoustic sound level of the transformer, energised at rated voltage and frequency shall be carried out either as per Indian Electrical & Electronics Manufacturers Association (IEEMA) or as per National Electrical Manufacturers Association (NEMA) procedure.

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For 30 MVA, 110 /27 kV Traction Transformer 6.3.6 Measurement of Partial discharge quantity Partial discharge quantity of the windings shall be measured in accordance with IS: 6209 and IS: 2026 (Part – III). 6.3.7 Measurement of harmonics of no- load current The magnitude of harmonics of no- load current, as expressed in percentage of the fundamental, shall be measured by means of a harmonics analyzer, in accordance with IS: 2026 ( Part- I ). 6.3.8 Type tests on parts, fittings and accessories The tests on the various parts, fittings and accessories shall be conducted as described below. 6.3.8.1 On load tap – changer 6.3.8.1.1 Tests shall be carried out thereon in accordance with relevant IEC 60214 / IS: 8468. 6.3.8.1.2 Test for temperature rise of contacts: the test shall be carried out at rated current. The temperature rise shall not exceed the limit specified in IS: 8468. 6.3.8.1.3 Mechanical endurance test: With the tap-changer in oil, 100 operations shall be done manually and 10,000 operations shall be done with the motor drive unit. An operation shall comprise moving the tap-changer from one tap position to the next higher or lower tap position. All the taps of the tap- changer i.e. + 7 tap position to the – 9 tap position shall be covered during the test. While testing with the motor drive unit the applied voltage for the motor drive unit shall be adjusted to the values indicated below, and the number of operations at each value of voltage shall be as indicated against each.

1. At the minimum voltage 2500 operations 2. At the maximum voltage 2500 operations 3. At the rated voltage 5,000 operations.

6.3.8.1.4 Milli- volt test: The test shall be done both before and after the mechanical endurance test to assess the condition of the contacts. The variation in the milli- volt drop values shall be not more than 20 %. 6.3.8.1.5 Short- circuit current test: The test shall be done in accordance with IEC 60214/ IS: 8468 with short –circuit currents as mentioned in clause 3.10.

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6.3.8.1.6 Dielectric tests: The tests shall be done in accordance with IEC 60214/ IS:8468. 6.3.8.1.7 Auxiliary circuits insulation tests: Auxiliary circuits including the motor and other auxiliary equipment shall be tested in accordance with IS: 8468. 6.3.8.2 Condenser bushings 6.3.8.2.1 The type tests shall be carried out in accordance with IS: 5621 on porcelain housing of the condenser bushings. The following shall constitute the type tests:

1. Visual inspection. 2. Verification of dimensions. 3. Electrical routine test. 4. Porosity test 5. Temperature cycle test. 6. Bending test.

6.3.8.2.2 The type tests shall be carried out in accordance with IS: 2099 on the prototype of the condenser bushings. The following shall constitute the type tests:

1. Wet power frequency withstand voltage test. 2. Dry lightning impulse voltage withstand test. 3. Thermal stability test. 4. Temperature rise test. 5. Thermal short time current withstand test. 6. Dynamic current withstand test. 7. Cantilever load withstand test. 8. Tightness test. 9. Test of tap insulation. 10. Tightness test at flange or other fixing device. 11. Measurement of partial discharge quantity.

6.3.8.3 Bushing type current transformers The bushing type current transformers shall be tested in accordance with IS: 2705 (Part-I & IV). 6.3.8.4 Buchholz relay The Buchholz relay shall be tested in accordance with IS: 3637. 6.3.8.5 Terminal connectors The terminal connectors shall be tested in accordance with IS: 5561.

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For 30 MVA, 110 /27 kV Traction Transformer 6.3.8.6 Temperature indicators The following tests shall be conducted on prototypes of OTI and WTI.

1. Accuracy with reference to a standard instrument. 2. Calibration of the indicators to reflect the actual temperature of the

oil/winding. 3. Dielectric test at 2.5 kV for 60 s. 4. Vibration test. 5. Dust and water splash test to IP 55 degree of protection.

6.3.8.7 Pressure relief device The following tests shall be conducted on the prototype of pressure relief device:

1. Air pressure test. 2. Leakage test. 3. Contact rating and operation test. 4. Dielectric test on contacts at 2.5 kV for 60 s.

6.3.8.8 Radiators The radiators shall be tested for air leakage at a pressure of 2.5 kg/cm sq. The pressure shall remain constant for 1 h to indicate that there is no leakage. 6.3.8.9 Insulating Oil The tests shall be carried out in conformity with IS: 12463 on the sample of new inhibited mineral insulating oil for use in the transformer. In addition to the requirement of IS: 12463, the insulating oil filled in the transformer shall also meet the following characteristics-

(i) Oxidation Stability (test method as per IS: 12422)

a. Neutralization value after oxidation (max.):0.2mgKOH/g

b. Total sludge value after oxidation (Max.): 0.05% by mass

(ii) SK value: less than 8%

(iii) Oxidation inhibitor (DBPC) content: 0.25 to 0.3 % by mass.

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For 30 MVA, 110 /27 kV Traction Transformer 6.4 Routine tests The following routine tests shall be performed on each transformer including the prototype unit in accordance with IS: 2026:

1. Visual examination 2. Insulation resistance test. 3. Measurement of no- load current. 4. Measurement of no- load loss. 5. Measurement of resistance of the windings. 6. Measurement of percentage impedance voltages. 7. Measurement of load loss. 8. Polarity test. 9. Voltage ratio test. 10. Dielectric tests comprising:

1)Separate- source voltage withstand test, and 2)Induced over voltage withstand test.

11. Recording of recurrent surge oscillogram (RSO). 12. Tests on on load tap- changer. 13. Measurement of capacitance and tan-delta values

6.4.1 Visual examination: A general examination shall be made to check that the transformer conforms to the approved drawings. Various items are accessible for maintenance, the quality of workmanship and finish are of acceptable standards and all parts, fittings and accessories are provided. 6.4.2 Insulation resistance test: The insulation resistance of the windings with respect to the earth and between the windings shall be measured using a 5 kV megger. 6.4.3 Measurement of no – load current: Measurement of no- load current referred to the primary side shall be done at:

1. 90%, 100% and 110% of the rated voltage at the principal tapping, and 2. the appropriate tap voltage at the + 7 tap and – 9 tap positions.

6.4.4 Measurement of no- load loss: Measurement of no- load loss referred to the primary side shall be done at:

1. 90 %, 100% and 110% of the rated voltage at the principal tapping, and 2. the appropriate tap voltage at the + 7 tap and – 9 tap positions.

6.4.5 Measurement of resistance of windings: The resistance of the windings shall be

measured at all tapings and computed at 750 C.

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6.4.6 Measurement of percentage impedance voltages: The percentage impedance voltages at principal, + 7 tap and – 9 tap positions shall be measured at rated current and at

ambient temperature and computed at 750 C. 6.4.7 Measurement of load loss: Load losses at rated current shall be measured at

principal, + 7 tap and – 9 tap positions at ambient temperature and computed at 750. 6.4.8 Polarity test: The polarity (subtractive) and marking of the terminals for the polarity shall be verified. 6.4.9 Voltage ratio test: Voltage ratio shall be measured at all tap positions. 6.4.10 Dielectric tests 6.4.10.1 Induced over voltage withstand test: The test shall be done by applying the test voltage across the entire secondary winding as per IS: 2026(Part III). 6.4.10.2 Separate-source voltage withstand test: The test voltage to be applied shall be as under:

1. Highest voltage for equipment Um, kV 52 123 2. Rated short duration power frequency

withstand voltage, kV 95 230

6.4.11 Recording of recurrent surge oscillogram (RSO): The oscillograms shall be taken at the + 7 tap, – 9 tap and principal tapping. 6.4.12 ests on on load tap changer: The tests shall be conducted in accordance with IS: 8468. 6.4.13 Measurement of capacitance and tan-delta values: The measurement of capacitance and tan-delta (dielectric loss factor) of the transformer windings shall be made by Schering bridge. 6.5 During the routine tests on any unit if it is found that the sum of the measured

losses (i.e. no- load and load losses) measured at – 9 tap position (corrected to 750C) exceeds the value defined in Clause 6.3.1.3.1(1), or if the no-load loss/ load loss at the principal tapping exceeds the maximum guaranteed figures, then the transformer shall be rejected. 6.6 The prototype approval shall be accorded after conducting all the type and routine tests stipulated in this specification and TIQ 2001 ver 1. If the prototype of a transformer conforming to this specification has already been approved in connection with previous supplies to Indian Railways, fresh type testing may be waived at the discretion of the Purchaser, provided that no changes what so ever in the design or material(s) used or the process of manufacture have been made. However, the Purchaser reserves the right to

406


conduct type tests if he deems it necessary to do so in the light of experience gained from previous supplies. 6.7 Only after approval of the original tracings of drawings incorporating changes, if any, as a result of the prototype tests and clear written approval of the results of the tests on the prototype is communicated by the Purchaser/DG (TI), RDSO, Lucknow, to the successful tenderer/manufacturer, shall he take up bulk manufacture of the transformer - which shall be adopted for the prototype. In no circumstances shall materials other than those approved in the design/drawings and/or during the prototype testing be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype. 6.8 The tenderer may quote separately his charges for short-circuit and temperature-rise tests. No charges shall be payable for any other type and routine tests. 6.9 Revalidation of type tests The type tests will be repeated at an interval every five years and / or considering the changes in the design or material(s) used or the process of manufacture. 7.0 Maintenance Manual, tools gauges etc. Five copies of the Erection, Commissioning, Operation and Maintenance Manual approved by RDSO shall be supplied to each consignee, in case order is more than 10 nos. In case order is less than 10 nos. 2 copies of manual shall be supplied. Two copies of manuals shall be supplied to the Purchaser and DG (TI), RDSO, Lucknow (India) for record. The successful tenderer/manufacturer shall list out the special tools, gauges and testing instruments/kits that will be required for inspection, adjustment and maintenance of the interrupter. Individual prices for the items included in the above list shall also be furnished. The exact quantities of tools, gauges and testing instruments /kits to be procured initially shall be decided at the time of contract for the interrupters based on the above price list. 8.0 Training of Indian Railway’s personnel The offer shall include the training of two personnel of the Indian Railways free of cost at the manufacturer’s works in India or abroad and at the maintenance depots/workshops on a Railway system or other public utility where transformers of similar/identical design are in operation. The total duration of training for each personnel shall be 2 weeks of which approximately one week will be at manufacturer’s works and one week on a Railway system or other public utility. If the country of manufacturer is not India, the cost of travel to that country and back will be borne by the Indian Railways. Other details shall be settled at the time of finalizing the contract/Purchase Order. 9.0 Packing, Delivery, Commissioning etc. 9.1 The transformer shall be transported depending upon the transport facilities available for the route i.e. by rail or truck or ship.

407


9.2 The transformer shall be dispatched with its core and windings along with the tap- changer assembly in the transformer tank filled with oil and the space above the oil filled with pure dry air or inert gas like nitrogen at a pressure slightly above atmospheric pressure. However, if there are limitations on account of weight, the tank shall be filled with nitrogen under pressure and the oil for the first filling shall be supplied separately in steel drums. In case the tank is filled with inert gas the temperature and pressure at the time of filling shall be marked conspicuously on the transformer. 9.3 All openings created on the tank by removal of any items shall be closed with suitable blanking plates. All the parts, fittings and accessories such as conservator tank, bushings, silica gel breather, radiator, Buchholz relay, temperature indicators and other items shall be packed / crated separately along with a packing list/check list in each crate containing the following particulars: Crate No. Description of item/ component in the crate

Approx.gross weight in kgf

Approx. outside dimensions in mm

All the matching parts shall be identical with the transformer Sl. No. or Work Order No. to avoid any mismatching at site. 9.4 The packing shall be done properly so that no damage occurs during transit. 9.5 All the parts, fittings and accessories for each transformer shall be so dispatched that they arrive at site together to enable erection of the complete without delay. 9.6 Necessary instructions for handling and storage of all items shall be included along with the packing lists. 9.7 In case of overseas supply, packing shall be sea worthy. 9.8 The transformer shall be erected and commissioned by the Purchaser. The successful tenderer/manufacturer shall invariably make available at site the services of an engineer of his to ensure, by his continued presence, that the process of erection, testing and commissioning of the transformer is in accordance with established practices. For this purpose prior intimation regarding the dates/period and locations at which the transformers are to be erected and testing / commissioning done shall be given by the Purchaser to the successful tenderer/manufacturer. No charges shall be payable by the purchaser to the successful tenderer/manufacturer for the services of his engineer in this regard. 9.9 If any transformer has been received at site in a damaged condition and in the opinion of the Railway's Engineer at site it is required to be repaired at the successful tenderer/manufacturer's works, the transformer shall be taken back to the works promptly and after repair, all necessary tests including the routine tests shall be done on the

408


complete transformer in the presence of and to the satisfaction of the Railway's Engineer prior to returning the transformer to site. Such tests are necessary to ensure that the quality of the workmanship during repairs is satisfactory and shall be done free of cost. Any tests, as decided by the Railway's Engineer at site shall also be conducted on the transformer at site free of cost. 10.0 Warranty The successful tenderer/manufacturer shall warrant that all equipment be free from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally accepted standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly. This warranty shall cover inspection of, payment for and acceptance of the equipment, but shall expire 30 (Thirty) months after the delivery at ultimate destination, or 24 (Twenty four) months from the date of commissioning and proving test of the equipment at ultimate destination in India, whichever period expires earlier, except in respect of complaints, defects and/or claims notified within 3(Three) months of the expiry of such date. Any approval or acceptance by the Purchaser of the equipment shall not in any way limit the successful tenderer/manufacturer’s liability. The successful tenderer/manufacturer’s liability in respect of any complaint, defects and/or claims shall not be limited to the furnishing and installation of replacement of parts free of any charge or the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer/manufacturer within 3(Three) months of their being first discovered during the warranty period of 3(Three) months from the date of expiry of warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned. The successful tenderer/ manufacturer shall, if required, replace or repair the equipment of such portion thereof as is rejected by the Purchaser free of cost at the ultimate destination or at the option of the Purchaser. Successful tenderer/manufacturer shall pay to the Purchaser value there of at the contract price or in the absence of such price at a price decided by the Purchaser and such other expenditure and damages as may arise by reason of the breach of the conditions herein specified. All replacement and repairs that the Purchaser shall call upon the successful tenderer/manufacturer to deliver or perform under this warranty shall be delivered and performed by the successful tenderer/manufacturer, promptly and satisfactorily and in any case within 2(Two) months of the date of advice to this effect. If the successful tenderer /manufacturer so desires, the parts that are removed may be taken over by him or his representative for disposal as he deems fit at the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.

409


For 30 MVA, 110 /27 kV Traction Transformer The warranty herein contained shall not apply to any material which shall have been repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer/manufacturer, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident. The decision of the Purchaser in regard to successful tenderer/manufacturer’s liability and the amount, if any, payable under this warranty shall be final and conclusive. 11.0 Spares & after sales-service & AMC 11.1 The Tenderer shall quote separately for the following essential spares for every lot of upto 5 transformers or part thereof. 1. One set of primary coil, secondary coil and tapping coil. 2. One primary bushing complete with parts, fittings and bushing type current

transformer. 3. One secondary bushing complete with parts, fittings and bushing type current

transformer. 4. One complete set of gaskets of all sizes required for use in the transformer. 5. One breather unit with silica gel. 6. One set of radiator banks. 7. One Buchholz relay. 8. One complete on load tap -changer. 9. One each of terminal connectors for primary and secondary side bushing terminals. 10. One set of valves. 11. One pressure relief device. 11.2 The successful tenderer / manufacturer shall make necessary arrangements for closely monitoring the performance of the transformer through periodical visit to the locations where they are erected for observations and interactions with the operating and maintenance personnel of Indian Railways. Arrangements shall also be made by the successful tenderer / manufacturer for emergency / standby spare parts being kept readily available to meet exigencies warranting replacement so as to keep the transformer in service with list down time. 11.3 Successful tenderer / manufacturer shall respond promptly on call given by RDSO/railway for any assistance by way of attending to failures, investigations into the causes of failures including the tests, if any, to be done and such other items with a view to seeing that the transformer serves the purpose for which it is procured. Besides, technical guidance to ensure proper operation and maintenance of the transformer shall be constantly rendered. 11.4 In the event of the purchaser requiring maintenance support through AMC, the tenderer shall quote for this separately alongwith his offer, the annual rate of AMC for 10 years period. The tenderer shall take necessary measures to ensure that the downtime of the equipment is the least.

410


For 30 MVA, 110 /27 kV Traction Transformer

Railway may incorporate clause in the tender documents for AMC such that payments are based on the availability/ downtime of the equipment in slab rates. A fixed period of time after communication of the failure, for which downtime shall be reckoned, will be decided by the purchaser/ railway. 12.0 Technical Data and drawings to be furnished alongwith tender 12.1 The tenderer shall furnish along with his offer, in the proforma at Appendix-A, the schedule of Guaranteed Performance, Technical and Other Particulars (SOGP, Part - I) for the transformer. The particulars shall be complete in all respects. The values/ information given in this SOGP, Part-I, will be used for technical evaluation of the tender. 12.2 Only the successful tenderer shall furnish the consolidated information as given in the proforma at Appendix-B, the schedule of Guaranteed Performance, Technical and Other Particulars (SOGP, Part - II) for the transformer. 12.3 The tenderer shall furnish the following information along with his offer: 12.3.1 Calculations for:

1. Temperature rise of winding at rated current.

2. Hot-spot temperature of the winding at 150% and 200% rated loads for 15

min and 5 min respectively.

3. Thermal withstand capacity of the windings for a short circuit of 5 s

duration.

4. Mechanical forces in respect of the following as per IEEMA (Indian

Electrical & Electronic Manufacturer's Association) formulae given ion

Appendix-C.

i) Asymmetrical short-circuit current.

ii) Hoop stress in primary and secondary windings.

411

iii) Compressive pressure in the radial spacers.

iv) Internal axial compressive force.

v) Axial imbalance force.

vi) Radial bursting force. vii) Resistance to collapse.

viii) Bending stress on clamping ring and densified wood.

ix) Maximum allowable torque on pressure screws for coil clamping

bolts at the time of tightening, if any. 5. Flux density with the characteristic curve. 6. Maximum value of inrush current.

412


For 30 MVA, 110 /27 kV Traction Transformer 12.3.2 Drawings for: 1. Outline general arrangement drawing giving complete details of the

transformer. 2. Arrangement of the core, windings and magnetic path. 3. Magnetizing characteristic of CRGO sheet steel. 4. Drawing showing elevation of the core and winding and other insulation materials. 5. A sectional view showing the position of core cylinders, winding blocks, vertical

ribs and other insulating materials. 6. Details of coil clamping arrangement. 7. General arrangement of the off-circuit tap - changer. 12.3.3 Other documents: 1. Quality assurance plan for the tendered transformer. 2. ISO certification regarding quality system manufacturing, testing facilities, R&D

facilities and reliability. 3. List of essential plant, machinery and testing facilities. 4. Up-dated calibration certificate for the testing equipment. 5. Type test reports for the relevant rating of the tendered transformer. 6. List of supplies & performance reports from the users for tendered

transformer. 12.4 The successful tenderer / manufacturer shall submit to DG(TI), RDSO, Lucknow for approval the following detailed dimensioned drawings as per Indian Railways standard in sizes of 210mm x 297mm or any integral multiples thereof:- 1. Outline general arrangement of the transformer indicating plan, front elevation,

side elevation with all parts, fittings and accessories, electrical clearances as well as salient guaranteed particulars.

2. Internal arrangement of the transformer indicating primary and secondary bushing lead connections, core to core- clamp earthing, core- clamp to tank earthing,

core- clamp to core-base bolting, and the locking arrangement of the core & coil assembly with the tank.

3. Cross sectional view of the core and windings with material specifications and makes. 4. Details of the pressure screws / oil dash-pot/ coil clamping bolts or other devices

and their location with materials specifications and makes. 5. Schematic view of the valves used on the transformer and the antitheft devices

as to diagram. 6. Transport outline dimensional diagram. 7. General arrangement of the on load tap-changer assembly with salient technical

parameters. 8. Tap-changer cubicle layout. 9. Schematic diagram for driving of on load tap-changer from remote control centre by

telecommand and corresponding telesignalling.

413


10. Name and rating plate of on load tap-changer. 11. General arrangement of marshalling box indicating protection control

equipment. 12. Wring diagram of protection and control circuits marshalling box. 13. Schematic diagram of protection and control circuits in marshalling box with

cable schedule. 14. Legend plate showing protection and control circuits for fitment in the

marshalling box. 15. Oil communicating type IS bushing for primary side including cross- sectional view, shed profile and salient electrical and mechanical characteristics. 16. OIP condenser bushing for secondary side including cross-sectional view shed

profile and salient electrical and mechanical characteristics. 17. Dimensional drawing, V-I characteristic and rating plate for bushing types current

transformers. 18. Rigid type terminal connector for primary side bushing terminal. 19. Expansion type terminal connector for secondary side bushing terminal. 20. Rating plate diagram of connections, both in English and Hindi versions. 21. Details of radiators including the painting schedule. 22. Details of breather 23. External cables run with cable schedule. 24. Details of ‘O’ ring and different gaskets to be used in the transformer 25. Any other drawings considered necessary by the successful tendered/

manufacture and/ or purchaser. 12.4.1 The format of the title sheet to be adopted for preparation of the drawings is attached at Appendix -G. 12.4.2 After approval, six copies of each of the approved drawings along with two sets of reproducible prints for each drawing shall be supplied to each consignee(s). Besides, two copies of drawings along with one set of reproducible prints and drawings on CD (in AUTOCAD 2000) along with hard copy after final approval of the drawings shall be supplied to DG, RDSO, and Lucknow. 12.4.3 Two copies of the "Operation / Maintenance Manual" for each transformer shall be supplied to the consignee(s). Two copies of the manual shall be supplied to the DG (TI), RDSO, Lucknow. While preparing the instruction and maintenance manual for inspection/test schedule for traction transformer issued by RDSO shall be taken into account. 13.0 Clause wise conformity, deviations etc. 13.1 The tenderer shall specifically indicate in a statement attached with his offer, his compliance with each clause and sub-clause of this specification. A separate statement shall be attached with the offer indicating references to the clauses where the tenderer deviate there from together with detailed remarks/justification. If there are no deviations, a ‘NIL’ statement shall be attached.

414


For 30 MVA, 110 /27 kV Traction Transformer 13.2 Any deviation from this specification which the tenderer proposes to improve upon the performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of the deviation with justification thereof are furnished, and are found acceptable by RDSO. 14.0 CAPITALISATION OF TRANSFORMER LOSSES The capitalized valve of transformer losses shall be as low as possible and commensurate with optimum no-load and load the losses. The capitalized value shall be computed as detailed at Appendix D and furnished with offer. Capitalized value calculated, as per Appendix D shall be added to the unit cost of the transformer for taking into consideration the cost of losses during its service life. 14.0 List of appendices used in the specification. Appendices enclosed with this specification are as follow. S.No. Appendix Description 1. Appendix-A Schedule of Guaranteed Performance, Technical and

Other Particulars – Part – I 2. Appendix-B Schedule of Guaranteed Performance, Technical and

Other Particulars – Part – II 3. Appendix-C Formula for Calculation of Short Circuit Mechanical

Forces 4. Appendix-D Capitalization of Transformer Losses 5. Appendix-E General Scheme for Traction Power Supply System 6. Appendix-F Overall Dimensions of the Transformer 7. Appendix-G Format of the Title Sheet to be adopted for Preparation of the Drawings 8. Appendix-H Nitrogen Injection Fire Prevention and Extinguishing System for Oil Filled Transformer 9. Appendix-I List of RDSO’s Approved Sources for Parts, Fittings and Accessories

*******

415

RDSO Specification No. TI/SPC/PSI/30TRN/1050 For 30 MVA, 110 / 27 kV Traction Transformer

APPENDIX-A SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS, SOGP- Part-I (GURANTEED PARTICULARS ARE TO BE ESTABILISHED BY INSPECTION, ACTUAL TESTS/TEST REPORTS) – Values / Information are to be furnished by each of the tenderers and this will be used for technical evaluation of the tenders. .S.No. DESCRIPTION SPECIFIED VALUE/INFORMATION

VALUE/ INFORMATION to be FURNISHED BY TENDERER

1 2 3 4 A. RATINGS/PARTICULARS 1. Name of the manufacturer 2. Country of manufacture 3. Reference to specification based

on which performance data is prescribed

TI/SPC/PSI/30TRN/1050 & IS:2026 (Part I to IV )

4. Rated power 30 MVA 5. i) Rated Primary current ii)Rated

Secondary current 6. Rated voltage:

i) Primary ii) Secondary (at no-load)

273 A 1111 A 110 kV 27 kV

7. Rated frequency 50 +/- 3% Hz 8. Temperature rise above ambient

temperature of 500C: 1) Oil: i)At rated load ii)At 150% rated load for 15 min iii)At 200% rated load for 5 min 2) Winding: i)At rated load ii)At 150% rated load for 15 min iii)At 200% rated load for 5 min

Maximum 400C

Maximum 500C

Maximum 600C

Maximum 600C 9. Hot -spot temperature of winding over

ambient temperature of 50 0C: i) At rated load ii) at 150% rated load for 15min

iii) At 200% rated load for 5 min 10. Interval of time between two successive overloads after continuous working at full load ,at maximum

ambient temperature of 50 0C: i)Between two consecutive overloads of 50% for 15 min ii)Between two consecutive overloads of which one is of 50% for 15 min and the other of 100% for 5 min

Maximum 1150C Maximum 180 minute

416

APPENDIX-A S.No. Description SPECIFIED

VALUE/INFORMATION VALUE/

INFORMATION to be

FURNISHED BY TENDERER

11. Losses: i) No-load loss at rated frequency and at rated voltage at principal tap

ii) Load loss(at 750C ) with rated current and frequency at principal tap iii) Total losses at rated current and frequency at principal tapping

Maximum 15 kW Maximum 117 kW

12. Impedance voltages (at 75 C) at rated current and frequency :i) Principal tapping ii) - 9 tap iii) + 7 tap

16 +/- 0.5) % 15 to 17 % 15 to 17 %

13. Abili ty to withstand short circuit: i) Thermal

ii) Dynamic

5 Sec 0.5 Sec.

14. Details of core: i) Type of core ii) Grade of core material (viz. MOH/Hi-B/ZDKH) and conforming specification iii) Flux density at principal tapping at rated voltage and frequency. iv)Thickness of steel stampings v)Core bolt Insulation withstand voltage

CRGO MOH, Hi-B or ZDKH 1.55 Tesla Maximum 0.27 mm max. 2 kVrms for 60 sec

15. Details of Windings : i) Type of winding : 1) Primary 2) Secondary ii) Ratio of width to thickness of copper conductor of winding. iii) Max. Current density at rataed current 1) Primary 2)Secondary iv) Dielectric strength for windings : 1) Full wave lightening Impulse withstand voltage: a) Primary winding b) Secondary winding 2) Lightening impulse chopped on tail withstand voltage: a) Primary winding b) Secondary winding 3) Separate source power frequency withstand voltagae :

Uniformly insulated concentric disc duly

interleaved Uniformly insulated interleaved disc duly

interceed Shall not exceed 5:1

2.5 A/mm2 2.5A/mm2

550 kV peak 250 kV peak

550 kV peak 250 kV peak

---

417


.S DESCRIPTION SPECIFIED oN VALUE/INFORMATION .

APPENDIX-A VALUE/

INFORMATION to be FURNISHED BY

TENDERER

a) Primary winding b) Secondary winding

4) Induced over voltage withstand value

16. On load tap-changer : i) Name of the manufacturer

ii) Country of origin

iii) Governing specification

iv) Number of tappings:

1) plus tappings 2) minus tappings

v) variation of voltages on different tappings

vi) Maximum rated through current

x) Voltage class

xi) Short circuit withstand current

xi) Rated voltage of control circuit

17. Bushings: i) Primary side: 1) Name of the manufacturer

2) Country of origin

3) Governing specification

4) Type designation

5) Voltage class 6) Rated current 7) Creepage distance

ii) Secondary side: 1) Name of the manufacturer



4) Type designation

230 kVrms 95 kVrms

2 x rated secondary voltage

----

------ TI/SPC/PSI/30TRN/1050, IEC 60214 & IS: 8468

Seven Nine

+ 7 tap and – 9 tap with per tap

voltage of 1.25 kV

600 A

145 kV

8 kA for 3 seconds

110Vdc

-----

-----

IS 2099 & IS 12676 TI/SPC/PSI/30TRN/1050

OIP condenser bushing

145 kV 600A

3625 mm (Minimum)

----

-----

IS 2099 & IS 12676 TI/SPC/PSI/30TRN/1050

OIP condenser bushing

418


.S DESCRIPTION SPECIFIED oN VALUE/INFORMATION .

APPENDIX-A

VALUE/ INFORMATION to be

FURNISHED BY TENDERER

5) Voltage class 6) Rated current 7) Creepage distance

18. Insulating oil: i) Governing specification ii) Source of supply

52kV 2500A

1600 mm (Minimum)

IS:12463 RDSO approved source

19. Type of transformer tank Bell type

20. Details of radiators: i) Make and type

ii) Type of mounting

21. Acoustic sound level at a distance of 1 m, when energised at rated voltage and rated frequency without load.

22. Partial discharge value at 1.5 Um/ 3 kV rms

23 Dimensions of the complete transformer including all parts, fittings and accessories:

1) Overall length 2) Overall breadth 3) From rail level to the topmost

point

75 dB Maximum

As per IS 6209 & IS:2026(Part-III)

8000 mm (Maximum) 7000mm (Maximum) 7500mm (Maximum)

24. Is warranty as per clause 10.0? Yes/No

25. Is the list of spares furnished or not? Yes/No.

26. Are the details of fire protection and

extinguishing system by nitrogen injection method including layout drawing and the equipment drawing with complete bill of materials given in the tender?

Yes/No.

419


For 30 MVA, 110 / 27 kV Traction Transformer

APPENDIX-B SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND O THER PARTICULARS, SOGP- PART - II (GURANTEED PARTICULARS ARE TO BE ESTABILISHED BY INSPECTION, ACTUAL TESTS/TEST REPORTS)

.S DESCRIPTION UNIT OF oN MEASUREMENT .

VALUE/

INFORMATION

1 2 3 4 A. RATINGS/PARTICULARS 1. Name of the manufacturer 2. Country of manufacture 3. Reference to specification based on

which performance data is prescribed 4. Rated power MVA 5. Primary current at:

i) Rated load A ii) 150% rated load for 15 min A iii) 200% rated load for 5 min A

6. Secondary current at: i) Rated load A ii) 150% rated load for 15 min A iii) 200% rated load for 5 min A

7. Rated voltage: i) Primary kV ii) Secondary (at no-load) kV

8. Rated frequency Hz

9. Max. Temperature rise above ambient temperature of 500C: 1) Oil:

i) At rated load ii) At 150% rated load for 15 min iii) At 200% rated load for 5 min

2) Winding:


10. Max. Hot -spot temperature of winding over ambient temperature of 50 0C:


11. Interval of time between two successive overloads after continuous working at full load ,at maximum ambient temperature of 500C:

i) Between two consecutive overloads of 50% for 15 min ii) Between two consecutive overloads of which one is of 50% for 15 min and the other of 100% for 5 min

0C 0C 0C

0C 0C 0C

0C 0C 0C

Minute Minute

420



APPENDIX-B

VALUE/

INFORMATION12. No-load current referred to Primary

side at rated frequency and at : i) 90% rated voltage A ii) Rated voltage A iii) 110% rated voltage A iv) Appropriate voltage at - 9 tap A v) Appropriate voltage at + 7 tap A

13. Power factor of no-load current at rated

voltage and rated frequency

14. Value of the inrush current at rated A voltage on primary side ,the secondary side being open circuited

15. Losses: i) Max. No-load loss at rated frequency and at: 1)90% rated voltage at the principal tapping kW 2)Rated voltage at the principal tapping kW 3) 110% rated voltage at the principal tapping kW 4)Appropriate voltage at - 9 tap kW 5)Appropriate voltage at + 7 tap kW

ii) Max. Load loss(at 750C ) with rated current and frequency :

1) Principal tapping kW 2) - 9 tap kW 3) +7 tap kW

iii) Max. Total losses at rated current and frequency:

1) Principal tapping kW 2) - 9 tap kW 3) + 7 tap kW

16. Resistance voltage (at 750 C ) at rated current at principal tapping:

i)Primary % ii)Secondary %

17 Reactance voltage (at 75 C) at rated current % and frequency at principal tapping

18. Impedance voltages (at 75 C) at rated current and frequency:

i) Principal tapping % ii) - 9 tap % iii) +7 tap %

19. Resistance (at 75 C) of primary Ω winding

421



APPENDIX-B

VALUE/ INFORMATION

20. Resistance (at 75 C ) of secondary winding at:

i) Principal tapping ii) + 7 tap iii) - 9 tap

21. Reactance of winding: i)Primary ii)Secondary at:

1. Principal tapping 2. + 7 tap 3. - 9 tap

22. Regulation (at 75 C) with rated current and at power factor of:

i) Unity ii) 0.8 lagging

23. Efficiencies: i) Efficiency (at 75 0C) at unity power factor:

1) 100% load 2) 75% load 3) 50% load 4) 25% load

ii) Efficiency at (75 0C) at 0.8 power factor lagging at:

1) 100% load 2) 75% load 3) 50% load 4) 25% load

iii) Percentage of rated load at which maximum efficiency occurs.

24. Ability to withstand short circuit: i) Thermal ii) Dynamic

25. Thermal time constant (calculated): i) for primary and secondary windings with respect to oil at:

1) rated current 2) 150 % rated current 3) 200 % rated current

ii) Complete transformer at rated current.

26. Temperature gradient between oil and winding at:

i) rated current ii) 150% rated current for 15 min. iii) 200% rated current for 5 min.

& & &

H H H H

% %

% % % %

% % % %

%

Sec Sec

Minute Minute Minute Minute

0C 0C 0C

422



APPENDIX-B VALUE/

INFORMATION

27. Temperature rise of oil: i) Calculated average temperature rise of oil at

1) Rated current 0C 2) 150% rated current for 15 min. 0C 3) 200% rated current for 5 min. 0C

ii) Estimated temperature rise of top oil at: 1) Rated current 0C

2)150% rated current for 15 min. 0C 3)200% rated current for 5 min. 0C

28. Details of core:

i) Type of core ii) Flux density at principal tapping at rated voltage and frequency. iii) Flux density at principal tapping at 110% rated voltage and frequency. iv) Thickness of steel stampings v) Grade of core material (viz. MOH/Hi-B/ZDKH) and conforming specification vi) Watt loss in watt/kg of the core lamination at 1.55 tesla and 50 Hz vii) Exciting VA/kg for core stampings at: 1) Flux density of 1.55 tesla 2) Flux density at rated voltage 3) Flux density at 110% rated voltage

viii) Exciting VA/kg for assembled core at: 1) Flux density of 1.55 Tesla 2) Flux density at rated voltage 3) Flux density at 110% rated

voltage. ix) Type of insulation between core laminations x) Type of joint between the core limbs and yoke. xi) Core bolt Insulation withstand voltage xii) Core bolt insulation flashover voltage

Tesla

Tesla

Mm

Watt/Kg VA/kg VA/kg VA/kg

VA/kg VA/kg VA/kg

kV

kV

423



APPENDIX-B

VALUE/

INFORMATION

29. Details of windings: i)Type of winding:

1) Primary 2) Secondary 3) Number of turns of primary

winding 4) Number of turns of sec. Winding

5) Number of parallel paths in

primary winding

6) Number of parallel paths in secondary winding

7) Is inter leaving/interhielding of the winding adopted to ensure better impulse voltage distribution in primary winding?

8) Is inter leaving/inter shielding of the winding adopted to ensure better impulse voltage distribution in secondary winding?

9) Is the insulation of end turns of primary winding reinforced?

10) Is the insulation of end turns of secondary winding reinforced?

ii) Mode of connection ( i.e. in series or in parallel of the portions of the primary and secondary windings on the two limbs of the core, if applicable:

1) Primary 2) Secondary

iii)Dimensions of the copper conductor used in the winding:

1) Primary 2) Secondary 3) Tapped primary

iv)Current density at rated current:

1) Primary 2) Secondary

v) Insulation used over the conductor (details of material and specification there for) vi)Type of joints , if any ,in the windings vii) Dielectric strength for windings : 1) Full wave lightening Impulse withstand voltage:


Yes/No

Yes/No

Yes/No Yes/No mmxmm mmxmm mmxmm A/mm2

A/mm2

kVpeak kVpeak

424



APPENDIX-B

VALUE/ INFORMATION

2) Lightening impulse chopped on tail withstand voltage:


3) Separate source power frequency withstand voltage:


4)Induced overvoltage withstand value viii) Minimum flashover distance to earth in oil of :

1) Secondary winding to core 2) Primary winding to yoke 3) Primary winding to tank

ix) Material used for coil clamping rings and specification therefor

x) Can either end of secondary winding be connected directly to earth: xi) Magnitude of axial precompressive force on the windings:

a) Primary b) Secondary

xii) Calculated maximum axial thrust in the windings due to dead short at the terminals:

a) Primary b) Secondary

xiii) Calculated short circuit forces: 1) Hoop stress in primary winding 2) Hoop stress in secondary winding 3) Compressive pressure in the radial

spacers 4) Internal axial compressive force

5) Axial imbalance force

6) Resistance to collapse

7) Bending stress on clamping ring

8) Radial bursting force

xiv) Arrangement to maintain constant pressure on the windings xv) Maximum permissible torque on pressure screws for coil clamping at the time of tightening, if any.

kVpeak kVpeak

kV kV kV

mm mm mm

Yes/No

T T

T T

Kgf/cm2

Kgf/cm2

Kgf/cm2

Kgf

Kgf Kgf

Kgf/cm2

Kgf

425



APPENDIX-B

VALUE/

INFORMATION

30. On load tap-changer : i) Name of the manufacturer

ii) Country of origin

iii) Type designation

iv) Governing specification

v) Is a separate tapped winding provided on primary vi) Number of tappings:

1) plus tappings 2) minus tappings

vii) Percentage variation of voltages on different tappings viii) Minimum contact pressure between moving and stationary contacts ix) Maximum rated through current x) Voltage class xi) Short circuit withstand current (thermal) for 3 seconds xii) Rated voltage of control circuit xiii) Tap changer motor particulars :

1) Make and type 2) Rated voltage 3) Rated current 4) Rated power 5) Speed 6) Class of insulation

31. Bushings: i) Primary side: 1) Name of the manufacturer



4) Type designation 5) Voltage class 6) Rated current 7) Visible power frequency discharge

voltage

8) Wet one minute power frequency withstand voltage

9) Lightening impulse withstand voltage

10) Creepage distance

Yes/No

%

kg A kV kA

V(dc)

V A KW Rpm

KV A

KV rms

KVrms

KV peak

mm

426



APPENDIX-B

VALUE/ INFORMATION

11) Weight of assembled bushing

ii) Secondary side: 1) Name of the manufacturer



4) Type designation

5) Voltage class

6) Rated current

7) Visible power frequency discharge

voltage 8) Wet one minute power frequency

withstand voltage 9) Lightening impulse withstand

voltage 10) Creepage distance 11) Weight of assembled bushing

32. Bushing type current transformers: i) Primary side: 1) Name of the manufacturer 2) Governing specification 3) Transformer ratio 4) Class of accuracy 5) Rated current 6) Rated output 7) Exciting current at the rated knee

point voltage 8) Rated knee point voltage 9) Secondary winding resistance

corrected to 750C 10) Short time thermal current and

duration

ii) Secondary side: 1) Name of the manufacturer 2) Governing specification 3) Transformer ratio 4) Class of accuracy 5) Rated current 6) Rated output 7) Exciting current at the rated knee

point voltage 8) Rated knee point voltage 9) Secondary winding resistance

corrected to 750C 10) Short time thermal current and

SOGP – Part-II

Kg

KV

A

KV

KV

KV peak

mm Kg

A VA mA

V

Ohm KA, sec

A VA mA

V

Ohm

427



APPENDIX-B

VALUE/ INFORMATION

duration KA, sec

33. Insulating oil:

i) Governing specification ii) Source of supply

34. Type of transformer tank 35. Details of radiators:

i) Make and type

ii) Type of mounting

iii) Overall dimensions ( LxWxH) mm

36. Details of Buchholz relay: i) Make and type

ii) Governing specification

iii) Provision of shut-off values on either side of the relay

and sizes

iv) Provision of alarm contact

v) Provision of trip contact vi) Rated current of contacts

Yes/No mm

Yes/No Yes/No A

428

37. Details of winding temperature indicator:

i) Make and type


iii) Number of contacts provided iv) Rated current of contacts A

v) Dielectric withstand value of kV

contacts. 38. Details of oil temperature indicator:

i) Make and type


iii) Number of contacts provided

iv) Rated current of contacts A

v) Dielectric withstand value of KV contacts

39. Details of magnetic oil level gauge: i) Make and type


APPENDIX-B

.S DESCRIPTION UNIT OF VALUE oN MEASUREMENT INFORMATION .


iii) Diameter of dial mm

iv) number of contacts provided

v) Rated current of contacts A

vi) Dielectric withstand value of kV contacts

40. Details of pressure relief device: i) Make and type


iii) Does it rest itself? Yes/No

41. Bimetallic terminal connectors:

i) Primary side:

1.source of supply

2.Governing specification

3.Type

4.Rated current

5.Temprature rise over an ambient temperature of 450 C while carrying rated current

6.Short time current and duration

ii) Secondary side: 1.Source of supply

2.Governing specification

3.Type

4.Rated current

5.Temperature rise over an ambient temperature of 450 C while carrying rated current

6.Short time current and durationA

0 C kA, sec.

A

0 C

429

KDSO Specification No. TI/SPC/PSI/30TRNFor 30 MVA, 110 / 27 kV Traction Transformer


42. Acoustic sound level at a distance of 1 m, when energised at rated voltage and rated frequency without load.

43 Partial discharge value at 1.5 Um/ 3 kV rms

44. Weights and dimensions: i) Net weight of core

ii) Net weight of copper: a) Primary winding b) Secondary winding

iii) Net untanking weight of core, frame and coils. iv)Net weight of insulating oil

v) Volume of insulating oil

vii) Total weight of cooling equipmen vii) Total weight of transformer without oil.

viii)Total shipping weight of complete transformer including all detachable parts, fittings and assemblies ix)Shipping weigh of largest package

x) Crane lift ( excluding slings) for untanking core and coils

x) Crane lift (excluding slings) for removal or primary side bushings xi) Crane lift (excluding slings) for removal or primary side bushings.

xii) Dimensions of the complete transformer including all parts, fittings and accessories:

1) Overall length 2) Overall breadth 3) From rail level to the topmost point

xiii) Minimum thickness of steel plate/ sheet used:

1) Bell tank 2) Tank bottom 3) Conservator\ 4) Radiator 5) Marshalling box. 6) Tap changer cubicle.

xiv) Overall shipping dimensions of the larges package ( LxBxH)

430



APPENDIX-B

VALUE/ INFORMATION

xv) Mode of transportation of transformer unit ( filled with Oil/nitrogen gas)

B. Other Particulars 45 Is the transformer tank fitted with lifting

pads? If yes what is the numbers of pads?

46 What is the number of inspection covers provided?

47. Are conduits/trays provided for cable run

48. Is the core electrically connected with the tank?

49 Will the gaskets to be used in the transformer give trouble free service for at least 12 years? If not indicate the life.

50. Is the core construction without core bolts?

51. Are the core bolts grounded, and if so how ?

52. Are the magnetic shunt pockets of core lamination provided inside the tank surface to absorb stray flux? If yes, the material specification shall be furnished

53. What is the number of radial spaces used in the ; i) primary windings ii) secondary windings.

54. What is the number of joints provided in the : i) primary windings ii) secondary windings.

Nos.

Nos. Yes/No Yes/No Yes/No

Yes/No Yes/No Yes/No

55. Are the spacers/blocks/angle rings of pre-compressed press boards? If no, indicate the material with specification.

56. Are arrangements made for ensuring automatic constant pressure on the coils? If no give the reasons.

57 Are the closed slots provided on the outer most winding for locking the vertical strips.? If no give the reasons

58. What is the periodicity for tightening of the coil clamping arrangement

59. What are the calculated short circuit currents for : i)Symmetrical:

1) Primary winding A 3) Secondary winding

ii)Asymmetrical: 1) Primary winding 2) Secondary winding.

Yes/No

Yes/No

Yes/no

Years

A A

431

.S DESCRIPTION UNIT OF oN MEASUREMENT . 60. What is the overflux withstand

capability of the transformer (max. permissible limit of flux density)?

A A

Tesla

61. Are windings pre-shrunk? Yes/No 62. Have the details of drying cycles of the

coils/coil assembly including final tightening values of pressure, temperature and degree of vacuum at various stages of drying been furnished. ?

63. Is a test tap provided in each of the primary side and secondary side bushings?

64. Are the porcelain housing of the bushings of single piece construction?

65. Is the shed profile of the porcelain of the bushing free from under ribs but has a lip?

66. Is the bushing type current transformer of low reactance type?

67. Is clause by Clause" Statement of compliance" attached?

68. Is “Statement of deviation" if any attached?

69. Does the tap changer have snap action? If not, give reasons.

Yes/No Yes/No

Yes/No Yes/No

Yes/No Yes/NO Yes/No Yes/No

70. Is the tap changer of the rotary type or

the sliding type?

Rotary/ sliding

71. Is the Buchholz relay provided with

two shut-off valves, one on either side ?

Yes/No

72. Is separate conservator tank and

buchholz relay provided for tap changing equipment?

Yes/No

73. Are fasteners of 12 mm diameter and

less exposed to atmosphere of stainless steel to grade 04 Cr 17 Ni 12 Mo to IS 1570 Part-V ?

74. Are the fasteners of more than 12 mm diameter exposed to atmosphere of stainless steel or MS hot dip galvanized?

Yes/No

Stainless steel/hot dip galvanized

75. Are test certificates for tests as per

clause 16.0 attached?

Yes/No

432

RDSO Specification No.TI/SPC/PSI/30TRN/1050 For 30 MVA , 110/27 kV Traction Transformer

S No

DESCRIPTION UNIT OF MEASUREMENT

0 APPENDIX-B VALUE/

INFORMATION

76. Are all the calculation required as per clause 17.3.1 attached?

Yes/No

77. Are all the drawings required as per clause 12.3.2 attached?

Yes/No

78.

a) Are all the parts , fittings and accessories from RDSO’s approved manufactures?

b) If not, list the items, which are to be type tested in the presence of the RDSO’s representative.

Yes/No

79. Is adequate space provided in the marshalling box for housing the wiring and components/ equipment?

Yes/No

80. Is warranty as per clause 23.0? Yes/No

81. Is the list of spares furnished or not? Yes/No

82. Are the details of fire protection and extinguishing system by nitrogen injection method including layout drawing and the equipment drawing with the equipment drawing with complete bill of materials given in the tender?

Yes/No

433


APPENDIX-C FORMULA FOR CALCULATION OF SHORT CIRCUIT MECHANICAL FORCES Namenclature

Ai= Total supported area of the inner radial spacer in cm2.

Ao=Total area of the outer radial spacer in cm2

At=Area of tie rods in cm2 a=Per unit turns , out of circuit , in the winding. bi=Thickness of inside winding conductor in cm Dmi=Mean diameter of inside winding in cm. di=Diameter of inner winding conductor in cm. TM=Current density in A/ cm2 E=Modulus of Elasticity of conductor in kg/ cm2 ez=per unit impedance Fa=Axial imbalance force due to tapping within winding in Kgf.Fc=Internal axial compression force in kgf. Fr=Radial bursting force in kgf. hw=Winding height in cm. Iph=Rated phase current in A. Isc=First peak value of asymmetrical short circuit current in A. N=Number of turns per phase in the circuit. Ns=Number of supports to be provided in the winding. Nt=Number of the tie rods. Pi=Compressive pressure in the inner redial spacers in kg/ cm2. Po= Compressive pressure in the outer redial spacers in kg/ cm2. Pt=Tensile stress in the rods in kg/cm2. R=Sum of the resistance of the transformer and system in ohm. Rdc=dc resistance of the phase at 75o cin ohm. Sn=Rated kVA. X=Sum of the reactance of the transformer and system in ohm. m=Hoop or compressive stress in kg/cm2.

Scope The calculation methods discussed below would be applicable to two winding transformers, having core type construction and concentric winding with tappings placed within the body of the outer winding.

1. Calculation of first peak value of Asymmetrical short circuit current . Isc=k 2(Iph/e)A. k 2 values are appended below (Ref.IS:2026 Part-I Clause 16.11.2) X/R= 1 1.5 2 3 4 5 6 8 10 ɛ14 k 2= 1.51 1.64 1.76 1.95 2.09 2.19 2.27 2.38 2.46 2.55 Note: For other values of X/R between 1 and 14 , the factor k 2 may be determined by linear interpolation.

2. Calculation of Asymmetrical short circuit Ampere-turns N x ISC

3. Hoop Stress ⌠m=(kxIph2xRdc) / (hwxez2 )

434


APPENDIX-C k (Cu)=0.03(k 2)2 /(2.55) k 2 as derived from item 1 above. The figure so calculated shall be less than 1250kg/cm2 . Note: The value of Iph2xRdc / hw referred to inner or outer winding shall be incorporated in the formula depending upon whether inner or outer winding stress is required to be calculated.

4. Radial Bursting force Fr=(2 x ⌠m x Iph x N)/ TM

5. Number of supports to be provided in winding (Flat conductor) Ns=(Dmi x 12x ⌠m)/(bi x E) Where,E=1.13x106

Kg/cm2.

6. Number of supports to be provided in winding (Round conductor) Ns=(8x Dmi x ⌠m)/(dix E)

7. Calculation of internal axial compression

Fc-(-) (34Sn)/ (ez x hw) Note: 1/3 Fc is acting on outer winding. 2/3 Fc is acting on inner winding. (-) Indiactes that force is acting towards the centre.

8. Calculation of Axial imbalance force due to tapping within the windings Fa=a x (Nisc)2x10-7kg.

Note 1 : If tapping are divided into two groups between the centre and the end of the windings, the force will be reduced to 1/4th of the figure obtained by the above formula. Note 2: If the compensating gap is provided in the untapped winding , the force will be half of that calculated above. Note 3 : For multi layer single coil design and other modes of Ampere –turns balancing actual unbalance Ampere-turns can be determined by residual Ampere-turn diagram. 9. Calculation of Maximum compressive pressure in the radial spacers Pi=(Fa+2/3Fc)/Ai kg/cm2 Po=(Fa+1/3Fc)/Ao kg/cm2

Note: Value calculated should not exceed 300 kg/cm2 for normal calendared press boards and 500kg/ cm2

for precompressed press boards.

10. Calculation of tensile stress in the tie rods Pt=(Fa – 1/3Fc)(Nt x At) kg/ cm2. Fa as derived from item – 8 above.

435


APPENDIX-C

Fc as derived from item – 7 above.

Note : The value calculated should be less than 2500kg/ cm2 for Mild steel tie rods.

11. Calculation of resistance to Collapse

(Applicable only to disc winding using rectangular conductor)

F(Crit)= 1.5E(Iph)2 x (m) / box Dmo x TM2x 108 + (450xAoxTMxb3)/Iph t Where : E = Modulus of Elasticity of conductor in kg/cm2. m =Number of turns x number of Parallel Conductors per coil. Iph =Rated phase current in A. Bo =Thickness of outer winding conductor in cm. Dmo =Mean diameter of outer winding in cm. TM =Current density in A/mm2 Ao =Total supported area of the outer radial spacer in cm2 12. Calculation kof most highly Stressed Coil

(Applicable for tapped winding only) Fa=(0.733 Q x Fr x log10(2aNc+1)t

Where: Q =Turns per coil adjacent to tapped out of coil, expressed as fraction of total turns in the limb. Fr =Radial force as derived from item – 4 above. A =Per unit number of turns out of circuit. Nc =Number of coils per limb.

13. Calculation of ‘W’ i.e. mechanical loading per centimeter of periphery WI =(fa)( xDm) kg/cm

Where Fa =Value as derived from item-12 above in kg Dm =Mean diameter of tapped winding in cm. Add 25 % extra for concentration of force and assume W = 1.25 WI. ⌠max= (WxL2xy)/(12xIo) kg/cm2 Where : L = Span in cm = xDm / ns) x bs ns =Number of spacers. Bs =Width of spacer in cm Y =Maximum distance from neutral axis for conductor in cm i.e. axial height of the winding

across the neutral axis divided by 2. Io = Moment of inertia of the coil i.e. bd3/12 b =Radial depth of coil in cm. d =Axial height of coil in cm. Maximum permissible value for ⌠max is 1250 kg /cm2.

436


APPENDIX-C

14. Calculation of bending stress on claiming rings

The stress on circular ring is as below: ⌠max = (6 x F x D) /(8 b x t2 x n2) t/cm2

Where : F =Total axial force (Fa-1/3Fc) in t. Fa =Value as derived from item – 8 above. Fc = Value as derived from item – 7 above.

D =Diameter of ring in cm. b =Width of ring in cm. t =Thickness of ring in cm. n =Number of jacking points. Maximum permissible value for max is 1100kg/cm, if circular permawood ring is used.

************

437


APPENDIX-D

CAPITALISATIN OF TRANSFORMER LOSSES

Following formula shall be used for the purpose of calculating the present worth of the transformer after taking in account capitalization of its losses. K=D(I+i)n-1 / i(l+i) n

Where K =Present worth of transformer in Rupees. D =Annual cost of combined no-load and load losses in Rupees. I =Discount factor @ 12% per annum. N =Life of transformer Substituting value of D, which is: D=(I+F2C)x365x24Xt/1000 Where, I =Maximum No-load loss in watt.

C = Maximum Load –loss in watt. F =Load factor T =Tariff in Rupees Assuming values of n as 50 years, F as 50% and T as Rupees 4.25 per kWh, the value Of K is , K = 37.23(I+0.25C)(1+0.12)50 -1 /0.12(1+0.12)50 =309(I+0.25C).

438

439

440

441


APPENDIX-H

NITROGEN INJECTION FIRE PREVENTION AND EXTINGUISHIN G SYSTEM FOR OH.FILLED TRANSFORMER 1.0 GENERAL DESCRIPTION:

Fire protection system based on principle of nitrogen injection shall be designed to prevent

tank deformation, detect and fire in oil filled transformers and to extinguish fires in the oil filled transformers. In accordance with provision of IE rule 64.2 ii and 64.2 f.i.

Electrical isolation of transformer is an essential pre-requisite for nitrogen injection and the

designed system shall have provision to verify the condition. The fire protection system shall get activated under condition of coexistent transformer differential protection relay and pressure relief valve. The system shall be designed to operate automatically. However it shall be designed for manual operation and manual over rides shall be provided for. The system shall be procured from manufacturer having effected similar supply. Performance experience and credentials of supplier shall be furnished along with the tender documents including the description of the system proposed to detect & extinguish fires and the type of sensors displayed. 2.0 SCOPE:

The fire prevention and extinguishing system shall be supplied complete with all parts, fittings and accessories necessary for its efficient and reliable operation. All such parts, fittings and accessories shall be deemed to be with in the scope of this specification, whether or not specifically mentioned herein.

Fire survival mineral insulated cables, able to withstand 750 C, of appropriate size shall be

used for connection of fire sensors / detectors in parallel. Fire retardant los some (FRLS ) cable of appropriate size shall be sued for connection between transformer signal box/ marshalling box to control box and control box to fire extinguishing cubicle. The testr certificate for the cables shall be submitted.

Laying of oil drain pipe, nitrogen pipe, electrical cables, control boxes, extinguishing

cubicle, nitrogen cylinder, PRV, fire dete4ctors and other equipments & accessories required for erection, testing, commissioning and performance demonstration of the complete fire protection system us inclined in the scope.

It shall be the responsibility of the tenderer, i.e. transformer supplied to coordinate with

supplier of the Fire Protection System for all arrangements for the complete erection, testing, commissioning and performance tests. The successful tenderer shall be required to furnish the detailed drawings and all technical particulars to RDSO through the pruchaser for scrutiny/approval. Civil Engineering work of construction of oil soak-pit for the drained oil and plinth for extinguishing cubicle is outside the scope of this specification.

3.0 INSPECTION AND TESTS:

The tenderer shall submit the test scheme to purchaser for approval of RDSO Inspection and testing shall be done based on the test scheme firmed up and approved by

442


APPENDIX-H RDSO. Proving test will be carried out on individual equipment of the system and the total system in the supplier’s workshop in presence of RDSO purchaser’s representative. Performance test of the complete system shall be arranged by the transformer manufactures at his works. These tests shall include simulation of activating condition and verification of the response of the complete fire protection system. In addition to above, additional tests as required necessary shall be conducted. RDSO representative shall witness the above tests on the prototype unit and after its successful completion , prototype approval of fire prevention and extinguishing system shall be issued by RDSO. The transformer manufacturer shall submit to the purchaser’s representative, along with other document the RDSO approved test reports, drawings and document including bill of material for balance quantity. 4.0 DRAWINGS AND MANUALS

Ten sets of approved drawings and ten sets of operation and maintenance manual, spare parts catalogue shall be supplied with the equipment.

5.0 Warranty, Spares & after sales-service & AMC: Clause 10.0 & 11.0 of the specification shall be applicable for warranty, after sale service and

AMC respectively. Following spares shall be supplied along with the system.

1. One spare set of nitrogen filled cylinders. 2. 50 % of the complement of all typed of sensors employed for detection of fire. 3. One pre-stressed non return valve. 4. One oil release unit. 5. One gas release units.

The list of recommended spares is to be submitted along with the tender.

***

443


APPENDIX-I LIST OF RDSO’S APPROVED SOURCES (VENDORS)- FOR PARTS, FITTINGS & ACCESSORIES OF TRACTION POWER TRANSFORMERS. S.No. Description of item Name of approved sources 1. Buchholz relay, gas operated double

float type, conforming to IS-3637 1. M/s Instrument & Control, Vadodra

2. M/s Atvus Industries, Calcutta

2. Pressure relief device (instantaneous reset type) with a trip contract.

M/s SukrutUdyog, Pune

3. Magnetic oil level gauge with an alarm contact (dial dia. 250mm)

M/s SukrutUdyog, Pune

4. OIP condenser bushings, conforming to IS : 12676 & IS-2099.

1. M/s ALSTOM Instrument Transformer Pvt. Ltd. Bangalore (for 245kV, 145 kV & 52kV class).

2. M/s Crompton Greaves ltd. Nasik (for 245kV, 145kV & 52kV class).

3. M/s Bharat Heavy Electricals Ltd. Bhopal (for 145kV & 52kV class).

4. M/s Transformers & Electricals, Kerala Ltd., Angamaly (for 145kV & 52kV class).

5. Pressed steel radiators, conforming to IEEMA-9/1990

1. M/s CTR Manufacturing Industries, Pune

2. M/s PE Engineers Pvt. Ltd., Hyderabad 3. M/s Thermal transfer products Pvt. Ltd.

Bangalore. 4. M/s HI-TECH Switchgears Pvt. Ltd.,

Navi Mumbai. 5. M/s BHEL, Bhopal

6. Mineral Inhibited Insulting oil,

conforming to IS: 12463 & Railways required characteristics.

1. M/s Apar Pvt. Ltd. (Special oil refiner), Mumbai

2. M/s Raj Lubricants (Madras) Pvt. Ltd. Chennai.

3. M/s Savita Chemicals Ltd., Mumbai 4. M/s Gulf Oil India Ltd. Mumbai 5. M/s Raj Petroleum Products ltd. Mumbai 6. M/s MP Petrochem Ltd. Indore 7. M/s Tashkent Oil Company (P) Ltd.

Vadodara 8. M/s Power Oil Petroleum Products

444


APPENDIX-I LIST OF RDSO’S APPROVED SOURCES (VENDORS)- FOR PARTS, FITTINGS & ACCESSORIES OF TRACTION POWER TRANSFORMERS. S.No. Description of item Name of approved sources 7. Bushing type current transformer,

PS class, conforming to IS: 2705 (Part I & IV)

1. M/s Transformers & Electricals, Kerala Ltd., Angamaly

2. M/s Bharat Heavy Electricals Ltd., Jhansi 3. M/s AU Electro Machines, Allahabad 4. M/s Mahendra Electrical Works, Thane 5. M/s Proection & Control Engineers,

Thane 6. M/s Narayna Powertech Pvt. Ltd.

Vadodara

8. Silicagel breather (Dehydrating) 1. M/s Atvus Industries (M/s Suvida Enterprises), Calcutta

2. M/s Yogya Enterprises, Jhansi 9. Wheel Valve, double flanged type

conforming to IS : 3639 1. M/s Manixon Industrial Corporation, Agra

2. M/s Girrnar Industries, Agra 3. M/s AUDCO India Ltd. Marinalal Nagar 4. M/s Petson Valves, Coimbatore

10. Temperature Indicators – WTI &

OTI, with four electrical contacts 1. M/s Perfect Controls, Chennai

2. M/s Precimeasure, Banglore 11. Remote tap position indicator,

winding temperature indicator, oil temperature indicator & Annunciator (digital type).

M/s Pradeep Sales & Service, Mumbai

12. Terminal Connectors (Rigid & expansion type) conforming to IS : 5561.

1. M/s Vinayak & Transmission Products (P) Ltd. Mumbai

2. M/s Nootan Engineering Industries, Vadodara

3. M/s Sree Engg. Corporation, Chennai 4. M/s Best & Crompton, Chennai

****

445

ANNEXURE – 1

Addendum to RDSO Specification no. TI/SPC/PSI/30 TRN/1050 for 30MVA, 11/27kV Single Phase traction Power Transformer only for the purpose of MRVC work of Design, Supply, Erection,

Testing and Commissioning of 110kV / 25kV Traction Substation at Jogeshwari & 9 switching stations in Mumbai Division of Western Railway at Mumbai (India)

Sr.No.

Reference Clause Page

1. Clause no.12 “Technical Data and Drawing to be furnished…..”

411 In the title after the work “furnished” delete the works “along

with the tender” and add “by successful tenderer”.

2. Clause no.12.3 “Technical Data

and drawings to be furnished by the successful Bidder”.

411 (i) Add “successful” after “the” and before “tenderer”

(ii) Delete “his offer” and add

“detailed design and drawing for approval of MRVC” at the end of the sentence.

447


SPECIFICATION

FOR

EARTHING OF POWER SUPPLY INSTALLATIONS

FOR 25kV, ac, 50 Hz, SINGLE PHASE TRACTION SYSTEM

No. ETI / PSI / 120 (2 / 91)

448

SPECIFICATION No. ETI / EST / 120 (2 / 91)



SPECIFICATION

FOR

EARTHING OF POWER SUPPLY INSTALLATIONS FOR 25 kV, AC, 50 Hz, SINGLE PHASE TRACTION SYSTEM


RESEARCH DESIGNS AND STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW 226011

449

FEBRUARY – 1991

GOVERNMENT OF INDIA – MINISTRY OF RAILWAYS

RESEARCH DESIGNS AND STANDARDS ORGANISATION CODE No. ETI / PSI / 120 (2 / 91) with C.S. No. 1 (10/93)*

CODE OF PRACTICE FOR EARTHING OF POWER SUPPLY INSTALLATIONS

FOR 25 kV, ac, 50 Hz, SINGLE PHASE TRACTION SYSTEM 1. SCOPE 1.1 This code of practice caters for general arrangements of system and equipment

earthing at 220 / 25 kV or 132 / 25 kV or 110 / 25 kV or 66 / 25 kV traction substations, 25 kV switching stations, booster transformer stations and auxiliary transformer stations. Low voltage (LT) electrical power distribution system, 25 kV overhead equipment system as well as signal and tele-communication equipment do not come within the purview of this code.

2. TERMINOLOGY 2.0 The following terms wherever occurring in this code shall, unless excluded or

repugnant to the context, have the meaning attributed thereto as follows :- 2.1 Combined Earth Resistance : The resistance of an earth electrode(s) with respect to

earth, with the earth electrode(s) connected to the metal work of electrical equipment other than parts which are normally live or carry current and the masts / structures but without connection with the traction rail(s).

2.2 Earth : The conductive mass of the earth, whose electrical potential at any point is

conventionally taken as zero. 2.3 Earth electrode : A conductor (mild steel (MS) pipe) for group of conductors in

intimate contact with and providing an electrical connection to earth. 2.4 Earthing grid : A system of a number of interconnected, horizontal bare conductors

buried in the earth, providing a common ground for electrical devices and metallic structures, usually in one specific location.

2.5 Equipment earthing : Earthing of all metal work of electrical equipment other than

parts which are normally live or current carrying. This is done to ensure effective operation of the protective gear in the event of leakage through such metal work,

450

the potential of which with respect to neighboring objects may attain a value which would cause danger to life or risk of fire.

• C.S. No. 1: Para 2.1, 2.11 and 16. vii added. • Para 2.3 and 11.1 modified.

2.6 System earthing : Earthing done to limit the potential of live conductors with respect to earth to values which the insulation of the system is designed to withstand and thus to ensure the security of the system.

2.7 Touch Voltage (E touch) : The potential difference between a grounded metallic

structure and a point on the earth’s surface separated by a distance equal to the normal maximum horizontal reach of a person, approximately one metre.

2.8 Step Voltage (E step) : The potential difference between two points on the earth’s

surface separated by distance of one pace, that will be assumed to be one metre in the direction of maximum potential gradient.

2.9 Mesh Voltage (E mesh) : The maximum touch voltage to be found within a mesh

of an earthing grid. 2.10 Power supply installation : The electrical equipments and associated structures

provided at a Railway Traction Substation or Switching Station, or Booster / Auxiliary transformer Station on the 25 kV over head equipment.

2.11 Traction Rail means a non-track circuited rail of a wired track, not required for

signaling purposes and which may be earthed. In non-track circuited sections, both the rails of a wired track are traction rails and in single rail track circuited sections, the traction rail is the non-track circuited rail.

3. OBJECT OF EARTHING

The object of an earthing system is to provide as nearly as possible a surface under and around a station which shall be at a uniform potential and as nearly zero or absolute earth potential as possible. The purpose is to ensure that generally all parts of the equipment, other than live parts are at earth potential and that attending personnel are at earth potential at all times. Also by providing such an earth surface of uniform potential under and surrounding the station, there can exist no difference of potential in a short distance big enough to shock or injure an attendant when short circuits or other abnormal occurrences take place. The primary requirements of a good earthing system are : i) It should stabilize circuit potentials with respect to ground and limit the

overall potential rise. ii) It should protect men and materials from injury or damage due to over

voltage. iii) It should provide low impedance path to fault current to ensure prompt and

consistent operation of protective devices during ground faults.

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iv) It should keep the maximum voltage gradient along the surface inside and around the substation within safe limits during earth faults.

4. GOVERNING SPECIFICATIONS

Assistance has been taken from the following standards / codes of practices in the preparation of this code of practice :

i) IS : 3043 – 1987 code of practice for earthing (first revision). ii) Indian electricity Rules – 1956 (latest edition). iii) National Electrical Code – 1985 of Indian Standards Institution. iv) IEEE Guide for safety in a.c. substation grounding, No. ANSI / IEEE

Standard 80 – 1986. 5. EARTH RESISTANCE

At each power supply installation, an earthing system as specified in this code shall be provided. S The combined resistance of the earthing system shall be not more than the following values :- S. No. Name of the station The limit of combined earth

resistance in ohms

1. Traction substation 0.5 2. Switching station 2.0 3. Booster transformer station 2.0 4. Auxiliary transformer station 10.0

6. EARTH ELECTRODES 6.1 The earth electrode shall normally be of mild steel galvanized perforated pipe of not

less than 40 mm nominal bore, of about 4 m length provided with a spike at one end and welded lug suitable for taking directly MS flat of required size at the other end. The pipe shall be embedded as far as possible vertically into the ground, except when hard rock is encountered, where it may be buried inclined to the vertical, the inclination being limited to 30 degree from the vertical. The connection of MS flat to each electrode shall be made through MS links by bolted joints to enable isolation of the electrode for testing purposes. A typical sketch of an earthing station with one earth electrode is shown in Fig. 1.

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6.2 Earth electrodes shall be embedded as far apart as possible from each other. Mutual separation between them shall usually be not less than 8.0 m (which is twice the length of the electrode).

6.3 If the value of earth resistance specified in clause 5 can not be achieved with a

reasonable number of electrodes connected in parallel such as in rocky soil or soil of high resistivity, the earth surrounding the electrodes shall be chemically treated. The earth electrode shall be surrounded in an earth – pit by alternate layers of finely divided coke, crushed coal or charcoal and salt at least 150 mm all-round. Though substantial reduction in earth resistance can be achieved by coke treated electrode, yet as this method results in rapid corrosion not only of electrode but also of steel frame work to which it is bonded, coke treatment shall be used only where absolutely necessary and such electrodes shall not be situated within 8.0 m of other metal work.

6.4 In high embankments, it may be difficult to achieve earth resistance specified in

clause 5 even after chemical treatment of electrodes. In those locations, use of electrodes longer than 4 m so as to reach the parent soil is recommended.

6.5 As far as possible, earth electrodes for traction sub-stations / switching stations

shall be installed within and adjacent to perimeter fence. At large sites, apart from securing a sufficiently low resistance and adequate current carrying capacity a reasonable distribution of electrodes is also necessary.

7. EARTHING ARRANGEMENT AT TRACTION SUBSTATION 7.1 Earthing grid. 7.1.1 An earthing grid is formed by means of bare mild steel rod of appropriate size as

indicated in clause 7.1.2 buried at a depth of about 600 mm below the ground level and connected to earth electrodes. The connection between the earth electrode and the grid shall be by means of two separate and distinct connections made with 75 mm X 8 mm MS flat. The connection between the MS flat and the MS rod shall be made by welding, while that between the earth electrode and the MS flats through MS links by bolted joints. The earth electrodes shall be provided at the outer periphery of the grid as shown in Fig. 2. As far as possible the earthing grid conductors shall not pass through the foundation block of the equipments. All crossings between longitudinal conductors and transverse conductors shall be jointed by welding. The transverse and longitudinal conductors of the earthing grid shall be suitably spaced so as to keep the step and touch potentials within acceptable limits; the overall length of the earthing grid conductors shall not be less than the calculated length (refer Annexure–I).

7.1.2 The size of the earthing grid conductor shall be decided based on the incoming

system voltage and fault level (refer Annexure I). The fault level considered shall take into account the anticipated increase in fault current during the lifespan of the station. The size shall be as given below :

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S. No. System voltage

(kV) Fault level

(MVA) Diameter of the grid Conductor (MS rod)

in mm 1. 66 up to 4000

above 4000 up to 5000 above 5000 up to 6000

32 36 40

2. 110 Upto 6000 above 6000 upto 8000 above 8000 upto 10000

32 36 40

3. 132 Upto 7000 above 7000 upto 10000

32 36

4. 220 Upto 12000 above 12000 upto 16000 above 16000 upto 2000

32 36 40

7.2 Buried rail. 7.2.1 A steel rail of section 52 kg / m (the one used for the railway track) and length

about 13 m shall be buried near the track at the traction substation at a depth of about one metre to form part of the earthing system. Two separate and distinct connections shall be made by means of 75 mm X 8 mm MS flat between the earthing grid and the buried rail. The buried rail shall also be connected by means of two separate and distinct connections made with 75 mm X 8 mm MS flat to the non-track circuited rail (s) in a single-rail track circuited section and to the neutral point (s) of the impedance bond (s) in a double – rail track circuited section.

7.2.2 In case where the feeding post is located separately away from the traction

substation, the buried shall be provided at the feeding post (where one terminal of the secondary winding of the traction power transformer of the substation is grounded).

7.3 System earthing. 7.3.1 One terminal of the secondary winding (25 kV winding) of each traction power

transformer shall be earthed directly by connecting it to the earthing grid by means of one 75 mm x 8 mm MS flat, and to the buried rail by means of another 75 mm x 8 mm MS flat.

7.3.2 One designated terminal of the secondary of each potential, current and auxiliary

transformer shall be connected to the earthing grid by means of two separate and distinct earth connections made with 50 mm x 6 mm MS flat.

7.4 Equipment earthing.

The metallic frame work of all outdoor equipments such as transformers, circuit breakers, interruptors and isolators, as well as steel structures shall be connected to

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the earthing grid by means of two separate and distinct connections made with MS flat of size as indicated below; one connection shall be made with the nearest longitudinal conductor, while the other shall be made to the nearest transverse conductor of the grid :

S. No. Equipment System voltage and fault level Ground conductor size

1. Equipments on the primary side of traction power transformer.

66 kV, upto 3000 MVA 110 kV, upto 5000 MVA 132 kV, upto 6000 MVA 220 kv, upto 10000 MVA

66 kV, above 3000 upto 6000 MVA

110 kV, above 5000 upto 10000 MVA 132 kV, above 6000 upto 12000 MVA 220 kV, above 10000 upto 20000 MVA

50 mm X 6 mm

75 mm X 8 mm

2. Equipments on the secondary side of traction power transformer.

50 mm X 6 mm

3. Fencing uprights/ steel structures.

50 mm X 6 mm

4. Doors / fencing panels.

6 SWG G.I. wire

7.5 Earthing inside control room.

An earthing ring shall be provided inside the control room by means of 50 mm x 6 mm MS flat which shall be run along the wall on teak wood blocks fixed to the wall at a height of about 300 mm from the floor level. The earthing ring shall be connected to the main earthing grid by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. The earthing ring shall also be connected to an independent earth electrode by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. The metallic framework of control and relay panels, LT a.c. and d.c. distribution boards, battery chargers, remote control equipment cabinets and such other equipments shall be connected to the earthing ring by means of two separate and distinct connections made with 8 SWG galvanized Iron wire. The connection shall be taken along the wall and in recesses in the floor. All recesses shall be covered with cement plaster after finishing the work. Connections between the MS flats shall be made by welding.

7.6 Earthing of lightning arrester.

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In addition to the earth electrodes provided for the main earthing grid, an independent earth electrode shall be provided for each lightning arrester. This earth electrode shall be connected to the ground terminal of the lightning arrester as well as to the main earthing grid by means of two separate and distinct connections made with 50 mm X 6 mm MS flat for the 25 kV side lightning arresters, and with 75 mm X 8 mm MS flat for the primary side lightning arresters, and with 75 mm X 8 mm MS flat for the primary side lightning arresters. The earth electrode shall be provided as close as possible to the lightning arrester and the connections shall be as short and straight as possible avoiding unnecessary bends. For lightning arresters provided for the traction power transformers, there shall also be a connection as direct as possible from the ground terminal of the lightning arrester to the frame of the transformer being protected; this connection shall also be made by means of two separate and distinct connections made with 50 mm X 6 mm MS flat for 25 kV side arresters, and with 75 mm X 8 mm MS flats for primary side lightning arrester.

7.7 Earth screen.

The area covered by outdoor substation equipments shall be shielded against direct strokes of lightning by an overhead earth screen comprising 19 / 2.5 mm galvanized steel stranded wire strung across the pinnacles of the metallic structures. The earth screen wires shall be strung at a height as indicated in the approved traction substation layouts (not less than 2.5 m above the live conducters) and shall be solidly connected to the traction substation earthing grid at each termination by means of 50 mm x 6 mm MS flat.

7.8 Earthing of fencing uprights and panels.

Each metallic fancing upright shall be connected to the traction substation main earthing grid by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. In addition, all the metallic fencing panels shall be connected to the uprights by means of two separate and disktinct connections made with 6 SWG G.I. wire. Al the metallic door panels shall also be connected to the supporting uprights by means of two separate and distinct connections made with 6 SWG G.I. wire.

7.9 Earthing at the point of 240 V ac 50 Hz supply for oil filtration plant.

The 240 V ac 50 Hz distribution board for power supply to oil filtration plant shall be connected to the main earthing grid by means of two separate and distinct connections made with 50 mm x 6 mm MS flat.

8. EARTHING ARRANGEMENT AT SWITCHING STATION 8.1 A minimum number of three earth electrodes (excluding the one to be provided

separately for the remote control cubicle earthing – refer clause 8.4) shall be provided at each switching station, and they shall be interconnected by means of 50 mm X 6 mm MS flat forming a closed loop main earthing ring. This ring shall be connected by two separate and distinct connections made with 50 mm X 6 mm MS flat, to the non-track circuited rail in a single-rail track circuited section and to the neutral point of the impedance bond in a double – rail track circuited section of the

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nearest track, so as to limit the potential gradient developing in the vicinity of the switching station in the event of a fault.

8.2 System earthing.

One designated terminal of the secondary of each potential, current and auxiliary transformer shall be connected to the main earthing ring by means of two separate and distinct connections made with 50 mm X 60 mm MS flat.

8.3 Equipment earthing. 8.3.1 All masts, structures, fencing uprights, and all outdoor equipment pedestals

including auxiliary transformer tank shall be connected to the earthing ring by means of two separate and distinct connections made with 50 mm X 6 mm MS flat. All fencing panels shall be connected to the supporting uprights by menas of two separate and distinct connections made with 6 SWG G.I. wire. All the metallic door panels shall be connected to the supporting uprights by means of two separate and distinct connections made with 6 SWG G.I. wire.

8.3.2 The metal casing of potential and current transformers shall be connected to the

mast / structures by means of two separate and distinct connections made with 50 mm x 6 mm MS flat.

8.3.3 The ground terminal of lightning arrester shall be connected directly to the earth

electrode by means of two separate and distinct connections made with 50 mm X 6 mm MS flat. The earth electrode shall be so placed that the earthing leads from the lightning arrester may be brought to the earth electrode by as short and straight a path as possible.

8.4 Earthing inside remote control cubicle.

An earthing ring shall be provided inside the remote control cubicle by means of 50 mm X 6 mm MS flat; the earthing ring shall be run along the wall on teak wood blocks fixed to the wall at a height of 300 mm from the floor level. The earthing ring shall be connected to the main earthing ring as well as to an independent earth electrode by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. The metal casing of LT a.c. and d.c. distribution borad, battery chargers, terminal board, remote control equipment cabinets and other such equipments shall be connected to the earthing ring by means of two separate and distinct connections made with 8 SWG G.I. wire. The connections shall be taken along the wall and in recesses in the floor. All recesses shall be covered with cement plaster after finishing the work. Connections of earth strips to each other shall be made by welding.

9. EARTHING OF NEUTRAL OF LOCAL POWER SUPPLY SYSTEM

At traction substations and switching stations where power supply at 415 V / 240 V, ac, 50 Hz, is taken from the local supply authority and having neutral earth at some distant point in the premises of the supply authority, the neutral of such supply shall

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also be earthed by means of two separate and distinct connections made with 6 SWG G.I. wire by connecting to an independent earth electrode.

10. EARTHING ARRANGEMENT AT BOOSTER TRANSFORMER STA TION 10.1 The minimum number of earth electrodes to be provided at each booster

transformer station shall be two. They shall be interconnected by means of 50 mm x 6 mm MS flat to form an earthing ring. The ring shall be connected by means of two separate and distinct connections made with 50 mm x 6 mm MS flat to the non-track circuited rail in a single-rail track circuited section or to the neutral point of the impedance bond in a double – rail track circuited section.

10.2 Each mast of the supporting gantry shall be connected at the bottom to the earthing

ring by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. The booster transformer tank shall be connected to the gantry mast by means of two separate and distinct connections made with 50 mm x 6 mm MS flat.

11. EARTHING ARRANGEMENT AT AUXILIARY TRANSFORMER STATI ON 11.1 The combined earth resistance at an auxiliary transformer station shall be not more

than 10 ohm. Normally, one earth electrode is sufficient at each auxiliary transformer section. The earth electrode shall be connected to the transformer mast by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. In addition, both the mast and the earth electrode shall be connected to the non-track circuited rail in a single-rail track circuited section or, to the neutral point of the impedance bond in a double-rail track – circuited section by means of 50 mm x 6 mm MS flat.

11.2 The earthing terminal on the transformer tank shall be connected to the mast on

which the transformer is mounted by means of two separate and distinct connections made with 50 mm x 6 mm MS flat. One terminal of the secondary winding of the auxiliary transformer shall be connected to the earthing terminal on the transformer tank and as well as to the mast by means of 50 mm x 6 mm MS flat. These connections shall be as short and straight as possible and avoiding unnecessary bends.

12. METHOD OF JOINTING

All the joints between the MS flats, MS rods or between MS flat and MS rod shall be made by welding only. No soldering shall be permitted. For protection against corrosion, all the welded joints shall be treated with red lead and afterwards thickly coated with bitumen compound.

13. PAINTING OF MS FLATS

For protection against corrosion, all the exposed surfaces of earthing connections (MS flats) above ground level shall be give all around two coats of painting to colour grass green, shade – 218 of IS : 5.

14. CRUSHED ROCK SURFACE LAYER

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At the traction substations and switching stations, a surface layer of crushed rock shall be provided to a thickness of about 100 mm. If considered necessary from the point of view of containing the step and touch voltages within the acceptable limits, higher thicknesses may be provided depending on calculation based on site conditions.

15. STEP AND TOUCH VOLTAGES 15.1 The formulae for calculating the tolerable touch and step voltages, estimated mesh

and step voltages, earth resistance, earth potential rise, size of earthing grid conductor and length of buried grid conductor are given in Annexure – I

15.2 The design for earthing grid shall be done separately for each location depending on

the conditions obtaining and those foreseen. 16. DRAWINGS

The following drawings (latest versions) issued by RDSO in connection with this code my be used for reference : i) Typical earthing layout of

Traction substation. ETI / PSI / 224 – 1 ii) Typical return current connection

of buried rail at traction ETI / PSI / 0212 – 1 substation.

iii) Typical earthing layout of subsectioning and paralleling station. ETI / PSI / 201 – 1

iv) Typical earthing layout of sectioning and paralleling station. ETI / PSI / 202 – 1

v) Typical earthing layout of booster transformer station. ETI / PSI / 211 – 1

vi) Typical arrangement of an earth electrode at a traction substation. ETI / PSI / 222 – 1

vii) Typical earthing arrangement for ETI / PSI / 708 An auxiliary transformer station.

**********************

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ANNEXURE – 1 FORMULAE FOR CALCULATION OF EARTHING GRID BASED ON IEEE GUIDE FOR SAFETY IN AC SUBSTATION

GROUNDING, No. ANSI / IEEE Std 80 – 1986 1.0 Tolerable touch and step voltage

0.116 1000 + 1.5 Cs (hs, K) Ps 1.1 E touch = ----------------------------------------- V (for 50 kg body) ts 0.116 1000 + 6 Cs (hs, K) Ps 1.2 E step = -------------------------------------- V (for 50 kg body) √ ts where,

Cs (hs,K) = 1 for crushed rock having resistivity equal to that of soil. If crushed rock resistivity is higher than that of soil, reference may be made to Fig. 3 for obtaining the value of Cs.

Ps = Resistivity of surface material (crushed rock) in ohm-metre. P = Resistivity of earth in ohm-metre. P - Ps K = -----------

P + Ps ts = Duration of sock current in seconds. hs = Thickness of the crushed rock surface layer in metres. 2.0 Estimated mesh and step voltageIG 2.1 E mesh = P x Km x Ki x ----- V L

IG 2.2 E step = P x Ks x Ki x ----- V L Where,

Ki = Corrective factor for grid geometry, which accounts for the increase in current density in the grid extremities.

= 0.656 + 0.172 n IG ---- = Average Current per unit length of L buried conductor in amperes / metre. 1 D2 (D + 2h)2 h Kii 8 Km = ----- 1n ( -------- + ------------- -- ------ ) + ------ 1n ---------- 2 ∏ 16 h.d 8 D.d 4 d Kh ∏ (2n-1)

Kii = 1 for grids with earth electrodes along the perimeter, or for grids with earth electrodes in the grid corners, as well as both along the perimeter and throughout the grid area.

1

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= ------------ for grids without earth electrodes or grids with only a 2/n few earth electrodes none located in the corners or on ( 2 n ) the perimeter. Kh = √1 + h / ho 1 1 1 1 n-2 Ks = ------ [ ------- + --------- + ------- ( 1 -- 0.5 ) ] ∏ 2h D + h D for value of h between 0.25 and 2.5 m. ho = 1 metre (reference depth of grid). D = Spacing between parallel conductors of grid in metres (same spacing in both directions). n = √nA . nB for calculating E mesh. = nA or nB, whichever is greater, for calculating E step. nA = Number of parallel conductors of grid in transverse direction. nB = Number of parallel conductors of grid in longitudinal direction. h = Depth of earthing grid conductors in metres. d = Diameter of earthing grid conductor in metres. L = Total length of earthing system conductor. = Lc + Lr for grids without earth electrodes or with only a few electrodes located within the grid but away from the perimeter. Lc = Total grid conductor length in metres. Lr = Total earth electrode length in metres. P = Resistivity of earth in ohm-metre. IG = As defined in para 4.1 below.

Note : The estimated values of mesh and step voltage should be less than the tolerable touch and step voltages respectively.

3.0 Earth resistance :

P ∏ P 3.1 Rg = -------- --------- + --------- 4 Ag L where, L = Total length of buried conductors in metres. Ag = Area occupied by the earthing grid in square metres. Rg = Station ground resistance in ohms. P = Resistivity of earth in ohm-metre. 4.0 Earth Potential rise : 4.1 Earth potential rise = Rg x IG where, Rg = Station Earth resistance in ohms. IG = Cp x Dr x Ig

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Cp = Corrective projection factor accounting for the relative increase of Fault currents during the station lifespan; for a zero future system Growth Cp = 1. Ig = r.m.s. value of symmetrical grid fault current in amperes. Df = Decrement factor for the entire duration of fault (to allow for the effects of asyrmetry of the current wave).

= 1.0 for fault current duration of 0.5 second or more. 5.0 Size of earthing grid conductor 5.1 A = I √ t / 80 where, A = Cross – sectional area of earthing grid conductor in square millimeters. I = r.m.s value of fault current in amperes. t = Duration of fault current in second (taken as one second )

Note : To allow for the effects of corrosion, the size of the grid conductor selected shall be such that its cross-section area is nearly twice that calculated above.

6.0 Minimum length of buried grid conductor

Km x Ki x P x IG √ ts 6.1 L > ------------------------------------------------------- for E mesh < E touch 116 + 0.174 Cs (hs, K) Ps where, L = Minimum length of buried grid conductor including earth electrodes in Metres. Ts = 0.5 second (assumed maximum duration of shock). Cs (hs, K), Km, Ki, P, IG and Ps have been defined earlier.

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SPECIFICATION FOR

LOW MAINTENANCE LEAD ACID 40 AH AND 200 AH CELLS FOR TRACTION

DISTRIBUTION SYSTEM.

No. RDSO/PE/SPEC/TL/0040-2003(Rev-0)

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Material SPECIFICATION No. RDSO/PE/SPEC/TL/0040-2003(Rev-0)


RESEARCH, DESIGN AND STANDARD ORGANISATION MANAK NAGAR LUCKNOW-226011

SPECIFICATION FOR LOW MAINTENANCE LEAD ACID 40 AH A ND 200 AH

CELLS FOR TRACTION DISTRIBUTION SYSTEM. 0.0 FOREWORD 0.1 In Traction Distribution System, 40Ah and 200Ah capacity cell is used for installations in the control rooms at unattended switching stations and traction sub stations. 0.2.1 The batteries for traction sub-stations and switching stations shall be of single cell construction and 55 cells constitute one set. 0.2.2 All types of traction sub-stations and switching stations shall be provided with single set of cell. 0.2.3 The rated capacity of cell shall be 2V, 40Ah for switching stations & 2 V, 200 Ah for traction sub-stations at 27 degree centigrade. 0.3 In the preparation of this specification assistance has been drawn from the following publications. (1) IS: 1146-1981 (2) IS: 6848-1979 (latest) (3) IS: 266-1993 (4) IS: 1069-1993 (5) IS: 6071-1986 (6) IS: 3116-1965 (7) IS: 8320-2000 (8) IS: 4905-1998 (9) IS: 1651-91(latest) (10) IS: 1652-91(latest) (11) RDSO Spec. No. ELPS/SPEC/TL/09 (Dec , 1996) with Amendment No.2 (12) RDSO Spec. No. ETI / PSI/21(6/81) with A& C Slip No. 1 (13) RDSO Spec. No. ETI / PSI/25(6/81) with A& C Slip No. 1

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1. SCOPE 1.1 This specification covers the design, manufacture, method of test and other requirements of low maintenance stationery lead acid batteries for installation in the control room at un - attended 132/25kV or 220/25kV traction sub stations (TTS) and at un-attended sectioning and paralleling posts (SPs) and sub-sectioning and paralleling posts (SSPs). The battery shall be of low maintenance design such that it requires very less topping up in the actual service. Frequency of topping up shall be not earlier than 9 months. However, attempt should be made to increase this period to 12 months. 1.2 The batteries shall be complete with all parts and accessories, which are necessary for their efficient operation including the supporting stands. All such parts and accessories shall be deemed to be with in the scope of this specification. 1.3 The batteries shall be delivered in the dry uncharged condition ready for filling electrolyte and use at site. Sufficient quantity of electrolyte required for first filling with 10% extra shall be supplied separately in non-returnable containers. 2.0 TERMINOLOGY 2.1 TYPE TESTS:-. These are intended to prove the general quality and design of a

given type of battery. 2.2 ACCEPTANCE TESTS:- Tests carried out on samples selected from a lot for the purpose of verifying the acceptability of the lot. 2.2.1 LOT :- All batteries of the same type, design and rating manufactured by the same factory during the same period using the same process and materials, offered for inspection at a time, shall constitute a lot. 2.3 ELECTROLYTE :- Aqueous solution of sulphuric acid for ionic conduction and Electro-chemical reaction during passage of current through a cell. 2.4 TERMINAL POST (lug): - A post (lug) of a cell or battery to which an internal electrical circuit is connected. Positive and negative terminal post shall be clearly and unmistakably identifiable. The positive terminal shall be marked with red colour in addition to '+' marking. 2.5 FLOAT :- A device for indicating the level of electrolyte in the cell container. 2.6 FLOAT GUIDE :- A removable bush of anti-splash and sealed type to facilitate easy vertical movement of float stem. 2.7 VENT-CUM-FILLING PLUG :-A removable plug for fitting into the vent hole.

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3.0 MATERIAL AND CONSTRUCTION 3.1 The cells shall be similar in type and shape. Lifting handle either moulded or rope type shall be provided with suitable strength. 3.2 The maximum overall dimensions of the cells up to terminal shall not exceed the values given in the table 1 of clause 7.1 of IS:1651-1991.The dimensions do not include the projection of float. 3.3 The weight of cells with the electrolyte shall not exceed to the value 31 Kg and 10 Kg for 200Ah and 40 Ah cell respectively. 3.3.1 The cell shall be so designed that the initial charging of the cell shall be completed within 75 hours as per the charging method to be prescribed by the manufacturers to the type testing authority as well as in the Maintenance Manual. Subsequent charging for conducting various tests shall be restricted to 15 hours. 3.3.2 All the positive or negative plates shall be insulated at edges to avoid side shorting. 3.4 CONTAINER AND LID 3.4.1 HARD RUBBER CONTAINER/LIDS : The cells shall be supplied in containers, which shall conform to IS:1146-1981 with latest amendment. The minimum height from the ball, as defined in the IS:1146-1981, when dropped which causes the fracture, shall not be less than 400mm (min. single time drop) for each side. However for 40 Ah cell the height which causes the fracture shall not be less than 200 mm. The design will provide for adequate safety margins for achieving the required strength. Cell lids shall be either drop-on type together with suitable gasket or of the deep sealing type suitable for use of bituminous sealing compound, with close-fitting terminal post outlets and with vent- holes suitable for accommodating the float guide and filling plug -cum-vent plugs. 3.4.2 PLASTIC CONTAINER/CELL LIDS : 3.4.2.1 The individual cells may be supplied with plastic containers / lids. The container/lid shall have adequate strength with design margins to meet the actual field conditions as prevalent over Indian Railways for which battery manufacturers shall wholly be responsible notwithstanding the approval given by the RDSO . Adequate measures shall also be taken by Manufacturers to avoid bulging of cells along shorter / longer sides of the cells. Despite of the above design measures having been taken by the manufacturers, if failures of cells on account of the container/lid material/inadequate design are reported from the field, the manufacturers shall

466

replace these cells with new cells having improved design with plastic/hard rubber container/lid as approved by the RDSO free of cost within the warranty period. If design of the container/lid is with strengthening member/rib, it may be provided inside or out side of the container/lid. In this case wall thickness refers to the base(web) thickness only and does not include thickness of rib or strengthening members. However the overall outer dimension shall not exceed the values specified as per clause 3.2.The design of container and lid shall generally conform to the following specifications. (1) Material Specification for PP-CP (Polypropylene Co polymer) Container/lid Fire retardant (V2 Grade) (2) Wall thickness of container 3.5 mm to 6.5 mm The outer wall thickness shall be measured on all sides of the container i.e longer side, shorter side, and base. However, the minimum wall thickness of container/lids shall not be less than3.0 mm if design of the container/lid is with strengthening member/rib. (3) Tests: These PP-CP containers shall be subjected to the tests as per Clause 7 of the

IS:1146-81 and the following tests shall be conducted during prototype testing 1. Verification of constructional requirements 2. Verification of marking and packing 3. High Voltage test 4. Drop Ball test 5. Plastic Yield test 6. Acid resistance test. In addition, a test for checking the proper sealing of the container with the lid as per 5.13 shall be conducted during prototype test as well as acceptance test, if the lifting handle is provided on the lid. 3.4.2.2 In order to have standardization of float guides, it should conform to drawing no. RDSO/PE/SK/TL/0031-02 (Rev 0 ). Float guides of dimensions different than above drawing may be accepted in special circumstances to be explained by the vendor. 3.4.3 MICRO POROUS VENT PLUG: Each cell shall be provided with adequate means, both for venting and for servicing of the electrolyte. The vent -cum-filling plug shall generally conform to RDSO drawing No. 4020/A Alt. 3 with the dome /filter made of ceramic or any other suitable fire retardant material. For smaller battery i.e. 40Ah size of vent plug can be smaller. The vent-cum-filling plug shall allow free escape of gases evolved during service and shall not permit electrolyte to come out on the surface of the lid. On removal of vent-cum -filling plug, drawing of the electrolyte sample, servicing and checking of electrolyte shall be possible.

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3.4.3.1 The material used for micro -porous vent plug shall have uniform porosity. It shall also be free from abnormalities such as crack, breakage, foreign matter, dent and shall conform to the following. The following tests shall be applicable on Micro -porous dome of the vent plug only and dome shall be taken out for this purpose. a) Porosity : 35 ± 5% Porosity of micro-porous filter shall be calculated as given below:- Weigh the sample in air (W1). Keep the sample in boiling water with few drops of wetting agent (Teepol ) for 30 mts. Weigh the sample in water (W2). Next weigh the wet sample outside water (W3). Calculate porosity as under: a) Porosity % = (W3-W2)-(W1-W2) ------------------------------X 100 (W3-W2) b) Breaking Strength: Shall not be brittle. To test this, a steel ball of 200 gm shall be dropped two times from the height of 400mm on the top and side of micro-porous dome. c) Acid resistance: Dry and weigh the (micro-porous body) dome (W1), Keep the dome in sulphuric acid of Sp. Gr. 1.3 at 40 Degree centigrade for 100 hours. Remove it from acid, wash free of acid, dry and weight (W2) . Calculate the percentage loss as follows W1- W2 -----------X100 W1 The loss of weight shall not be more than 0.5% d) Permeability : The full charge cell shall be fitted with vent plug and charged at 2.5 times of C10 rate for 4 hours. All sealed Float guides shall be in position properly except the one where manometer with water is fitted. The cell shall not develop positive pressure more than 2 mm of water column inside the cell. e) Dimension : Shall generally conform to RDSO's drg. No. SKEL-4020/A Alt. 3 or as approved by RDSO f) Plastic Component : Plastic component to which the micro -porous top is bonded shall be free from crack, flash, pin hole, air bubble, uneven shrinkage foreign particles etc. and shall conform to the following (Ref. Drg. SKEL-4020 Alt. 3) : ABS Fire retardant or superior quality Acid Resistance : No perceptible change Heat : NO deformation at 70 deg. C

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3.4.3.2 DIA AND PITCH THREAD:- The micro-porous vent cum- filling plug and sealed float guide dia shall be 27 mm and pitch of thread shall be 3 mm as per Drawing No. SKEL-4020/A Alt. 3 (sheet no.2 )

3.4.3.3 Each cell shall have one micro porous vent -cum -sealed float guide type for 40Ah and having dome /filter made of ceramic or any other suitable fire retardant material and meeting the requirements specified in clause 3.4.3 3.4.3.4 For 200 Ah each cell shall have one float guide sealed type and one vent-cum-filling plug as mentioned above. 3.4.3.5 Each cells (i.e. 40Ah/200Ah) shall be provided with two terminal lugs made of lead alloys, one negative and one positive according to fig. 1 of IS: 6848 except the thickness of lug which shall be 5 mm minimum for 40Ah and 12 mm for 200Ah . The positive terminal lugs shall have rounded edges and the negative terminal lugs shall have pointed edges, so to be easily distinguishable ( fig. 1 of IS:6848-79) 3.5 INTER -CELL AND END -CELL CONNECTORS : 3.5.1 Inter -cell connectors for one set consisting of 55 cells of 40Ah and 200 Ah shall be provided. The quantity to be supplied is given below. i) Inter cell connector = 52 numbers ii) Inter row connector = 2 numbers (Cell No. 14-15 and 42-43) iii) Take off terminal = 2 numbers (End cells) iv) Inter tier connector = 2 numbers (Cell No. 28 & 29) v) Fasteners = 220 numbers The fasteners M6X30for 40 Ah and M8x30 for 200 Ah shall be used. 3.5.1.1 Connector: (i) The cable connectors should have lead coating to withstand any corrosive attack.

The thickness of the lead coating of lugs shall not be less than 25 microns. The lead coating thickness shall be measured in accordance with Appendix 'F' of IS: 6848-79 with Amendment No 1,2 & 3.

(ii) The cables shall be of elastomeric type with composition class -6 of Table no. 1 of

RDSO approved make conforming to RDSO Specification NO. Spec./E-14/01 Part I (Rev. II)-1993.

(iii) The design shall be such that the voltage drop across the cell cable connector in the battery bank, shall not be more than 15mV per connector at C10 rate. However, efforts shall be made to keep this voltage drop as minimum as possible. Cable connector shall be of size 18 Sq. mm for 40Ah and 40sq. mm for 200 Ah. respectively.

(iv) In the design, adequacy of contact pressure leading to low contact resistance shall

be considered and accordingly suitable fastening arrangements shall be suggested

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/provided by the manufacturers. The details of recommended testing procedures and its frequency to ensure low voltage drop etc. shall be laid down by the manufacturers with consultation of RDSO.

3.5.2 Nut and Bolts for connecting the cells shall be made of copper, brass, stainless steel or any other suitable alloy and effectively lead coated to prevent corrosion. However acid resistance stainless steel bolts and nuts need not be provided with lead coating. 3.6 ELECTROLYTE : It shall be prepared from battery grade sulphuric acid conforming to IS: 266-1993 with latest amendment. 3.6.1 A suitable electrolyte level indicator indicating lower and upper limits shall be fitted to facilitate checking of electrolyte level in opaque containers. The materials used shall be acid proof and shall not deteriorate during service. 3.6.2 The specific gravity of electrolyte when the cells are in fully charged condition at 27 degree Centigrade shall be between 1.210 to 1.220. The specific gravity shall be corrected to 27 degree Centigrade using the formula given under cl. 3.2.2 of IS:8320 1982. 3.6.3 WATER: - The water used for topping up and preparing electrolyte shall conform to IS:1069-1993 3.7 SEPARATOR:- Separator shall be Micro porous rubber, PVC or any other material conforming to IS:6071-1986. The volume porosity shall be not less then 35% 3.8 SEALING COMPOUND : Sealing compound, if bitumen based shall conform to IS:3116-1965 with latest amendment. 3.9 BATTERY STAND : Supply of battery stand is optional and should be supplied if asked by the purchaser with each battery set. The battery stand shall be of double row double tier construction made of 4.0 mm thick M.S to accommodate the battery. (3 mm thick MS can be used for 40 AH cells) The battery stand shall be painted all over with three coats of acid resisting varnish conforming to IS:342-1976. The battery stand shall be provided with cell number plates and shall be manufactured as per drawings approved by the purchaser. 3.9.1 Electrical insulating grade and acid resistsant PVC sheet, not less than 3mm thick, for supporting the cells on the battery stand and necessary support insulators shall be supplied to suit the battery stand. 4.0 SERVICE CONDITION 4.1 The batteries are intended for use in moist tropical climate in India where the maximum ambient temperature may reach 45 deg. C in shade, the daily average maximum ambient reaching 35 deg. C, with a relative humidity reaching up to 100%

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4.2 40Ah batteries are required as a reliable power source for operation of the interrupter and the various control/indication circuits at the unattended 25KV switching stations, located along side Railway track for controlling power supply to the traction overhead equipment. 200Ah batteries are required as a reliable power source for operation of switchgear and various control /indication circuits at the unattended traction sub-station. 4.3 The batteries will be normally kept on trickle charge by suitable battery charger. During AC supply failure or battery charger failure the battery will be called upon to delivery the full load for operation of the interrupters and the various control/indication circuits. 5.0 RATING: 5.1 RATED CAPACITY : The rating assigned to the battery shall be capacity (C10) in ampere hour (after correction at 27 degree centigrade temperature) when the cell/ battery is discharged at 10 hr rate to the end voltage of 1.85V per cell. 5.2 DECLARED CAPACITY : Since the declared C10 capacity of the battery is generally higher then rated C10 capacity, the manufacturer will advice the declared C10 capacity of the battery. 5.3 OBTAINED CAPACITY : Obtained capacity is the capacity obtained during the discharge of cell upto 1.85 V at 10 hours rate of the rated capacity of the battery. The variation between declared capacity and obtained capacity shall not be more than ±3 percent. 5.4 TESTS AND PERFORMANCE: 5.4.1 Classification of tests 5.4.2 Type tests- The following shall constitute the type tests. All these tests shall be started after 3 cycles of charge/discharge at 10 hour rate. All these tests shall be conducted at 27±3 degree Centigrade unless and otherwise specifically mentioned. a. Capacity at 10 hrs. rate (Obtained Capacity) according to cl. 5.6 of this spec. b. Watt hour and Ampere hour efficency tests according to Clause 5.7 of this spec. Watt hour efficency shall not be less than 80 percent and Ampere hour efficency shall not be less than 95 percent. While conducting this test a minimum rest of 12 to 24 hours shall be given between each charge/discharge. c. Retention of charge according to clause 5.8 of this spec. Loss of capacity shall not be more than 3 percent of the initial capacity (OTC) after 14 days. For this battery can be stored at room temp. but not less than 22 degree centigrade. Charge/Discharge for this test shall be conducted at 27±3degree centigrade.

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d. Life test shall be conducted according to clause 5.9 of this specification. After completion of life cycle test the cell shall be cut opened and examined to arrive at the reason for reduction in capacity.

e. Storage test according to clause 5.10 of this spec. f. Air pressure test according to clause 5.14 of this spec. g. Checking of dimensions, mass, marking and workmanship according to clause 3 and 6.0 of this spec. h. Material and component specification verification test according to clause 7.0 of

this spec. i. Loss of water as per clause 5.11 of this spec. j. Test of Micro- porous vent plug as per Clause 3.4.3 of this spec. k. Equilibrium float current test as per Clause 5.12 of this spec. l. Sealing of container with lid as per clause 5.13 5.5.0 SEQUENCE OF TYPE TESTS: The sequence of type tests and the number of samples required shall be in accordance with Appendix "C". 5.5.1 If any of the samples fails in the relevant type tests, the testing authority may call for fresh samples not exceeding twice the original number of cells tested in that particular test and subject them again to test(s) in which failure occurred. If there is any failure in the retest(s), the type shall be considered as not having passed the requirements of this standard. 5.5.2 DURATION OF TYPE TEST: Type tests as per clause 5.4.2 shall be completed within six months (Maximum) from the date of starting the type test. Except storage test which shall be completed in two years from the date of starting the test. 5.5.3 INSPECTING AUTHORITY : The type test as per clause 5.4.2 of cells shall be conducted by the representative of RDSO/Lucknow, India at the works of manufacturers at their cost. 5.5.4 ACCEPTANCE TESTS: 5.5.4.1 The following tests shall be conducted as acceptance tests:-

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a. Capacity test at 10hrs. rate according to clause 5.6 of this spec. The capacity obtained shall not have variation of more than ± 5 percent of the capacity obtained (as approved by RDSO on the capacity obtained) during prototype testing. The weight of dry cell shall not vary more than ± 5 percent of the weight obtained during prototype testing. b. Checking of dimensions, mass, markings and workmanship as per clause 3 & 6. c. Checking of container strength on assembled cell shall be done by dropping a ball from a height of 400 mm for 200Ah cell and 200 mm for 40Ah cell as per clause 7.8 of IS:1146-1981. The container should not crack. For verification of crack, air pressure test shall be done. This test shall be conducted on five No. of assembled cell for each lot. 5.5.5 SAMPLING SCHEME AND CRITERIA FOR ACCEPTANCE: A recommended sampling scheme and criteria for the acceptance of the lot for various lot sizes is given in Appendix 'D'. 5.6 TEST FOR CAPACITY AT 10HRS. RATE 5.6.1 After standing on open circuit condition for not less than 12hrs. and not more than 24 hrs. form the completion of a full charge, the battery shall be discharged through a suitable resistance at a constant current I= 0.1X C10 amperes, and discharge shall be stopped when the closed circuit voltage across the battery terminals falls to 1.85 volts per cell. 5.6.2 At this rate of discharge, hourly voltage readings may be taken until the battery voltage approach 1.90 volts per cell after which the readings shall be taken every 15 minutes until the voltage falls to 1.85v/cell. 5.6.3 On the first discharge the battery or cell shall give ±3 percent of declared capacity. 5.6.4 The battery shall be charged at normal charging rate immediately after discharge. The charging of batteries may be carried out for test purposes using constant potential charging method or constant current charging method as recommended by the manufacturer. 5.6.5 The capacity in Ampere hour shall be obtained by multiplying the discharge current by the total time of discharge in hours and the product so obtained shall be corrected to a temperature of 27 degree cerntigrade by the following formula:- The capacity at 27 deg. C. = CT -------------- 1+ K(t-27)

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Where CT is the observed capacity at t degree Centigrade. K is the variation factor 0.0043. t is the average room temperature in degree Centigrade. 5.6.6 The capacity at 10 hrs. rate shall within ± 3 percent of declared capacity . 5.6.7 After 10 hrs discharge the cells/battery should be charged at normal charging period within 15 hrs. 5.7 TEST FOR AMPERE HOUR & WATT HOUR EFFICENCY 5.7.1 The following method shall be used for determining the maximum ampere hour and watt-hour efficiencies. 5.7.2 Ampere hour efficiency: A fully charged battery shall be discharged at I=0.1xC10 amperes to a end voltage of 1.85 volts/cell, care full measurements being made of exact number of ampere hours delivered. On the recharge the same number of ampere- hours are put back at the same current. A second discharge shall then be made to the same cut off voltage as before. The efficiency of the battery is then calculated as the ratio of the ampere- hour delivered during the second discharge to the ampere hour put on the charge. 5.7.3 Watt hour efficiency. The watt hour efficiency shall be calculated by multiplying the ampere - hour efficiency by the ratio of average discharge and recharge voltages. The values of discharge and recharge voltages shall be calculated from the log sheets for ampere hour efficiency. 5.8 TEST FOR RETENTION OF CHARGE The object of this test is to determine the loss of capacity of a battery unit on open circuit during a specified period. 5.8.1 The battery unit shall be fully charged at the normal charging rate specified by the manufacturer and it shall then be subjected to two consecutive capacity test discharges in accordance with clause 5.6, the value of the initial capacity, C being calculated as the mean of the two results thus obtained. 5.8.2 After a complete recharge and after cleaning the surface, the battery unit shall be left on open circuit for a period of 14 days without disturbance at ambient temperature. 5.8.3 After14 days of storage of the battery unit shall be discharged in accordance with clause 5.6. The value of the capacity measured after storage shall be denoted by C1. 5.8.4 After the discharge the battery unit shall be fully charged at the normal charging rate recommended by the manufacturer. 5.8.5 The loss of capacity's expressed as a percentage, shall be calculated from the formulae.

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S= C- C1 ----------- X100 C 5.8.6 Requirement: The loss of capacity calculated as in 5.8.5 shall not be more than 3 percent over 14 days storage period. 5.9 LIFE TEST It should be conducted as per clause 12.8(endurance test ) of IS1651-1991 applicable to normal cells. 5.9.1 REQUIREMENT: The cell shall give not less than 9 hour of discharge at 10 hour rate, till end voltage of 1.85 volt. 5.10 STORAGE TESTS 5.10.1 The cell/battery unit shall be capable of being stored unfilled for a period of 24 months from the date of sealing by inspecting authority. After storage for the specified period, the battery unit shall be tested as per clause 5.6 5.10.2 The capacity after 24 months, when tested as above shall be not less than ± 3 of the obtained capacity. 5.11 LOSS OF WATER TEST: 5.11.1 After fully charging the cell it should be cleaned and dried. It should be weighed immediately but not exceeding one hour after drying with an accuracy of 0.05 percent or maximum least count of 50gm for the balance used. Then all vent cum-filling plugs should be closed tightly and connected to constant voltage charger keeping the voltage 2.4 ±0.05 volts per cell for 21 days in water bath at the temperature of 50± 2 degree centigrade. Thereafter cell is removed from circuit and dried. After this it is weighed accurately. 5.11.2 The water loss shall not exceed 0.8gm/Ah/cell of the obtained capacity. 5.12 EQUILIBRIUM FLOAT CURRENT TEST : 5.12.1 This test shall be conducted during the initial three days (72 hours) of water loss test. The cell under test shall be kept in water bath at 50± 2 degree Centigrade. Charging voltage shall be 2.4 ±0.05 V per cell. The float current shall be measured and recorded. It shall not be more than 3mA/AH of the obtained test capacity. 5.13 TEST FOR SEALING OF CONTAINER WITH THE LEAD The test shall be conducted after filling the cell with the electrolyte up-to-the maximum permissible level. The filled battery shall be kept in water bath of temp. 50 ± deg. C for 2 hours. A jig shall hold the battery container alongwith a dead weight equal to the weight of

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fully topped up battery. The battery shall be lifted by the lifting handle provided on the battery lid. The same shall hold for 5 minutes. The cell lid shall not show any visible sign of movement at the sealing joint. 5.14 TEST FOR AIR PRESSURE The sealing of each cell of the battery shall be checked by compressed air at a pressure equal to 700 mm of water. The volume of tubes and auxiliary parts in connection with the cell under pressure shall not exceed 0.5 liter. Air pressure in the cell shall be noted 15 seconds after the supply has been disconnected and it shall not fall below 670 mm of water. 5.15 TEST EQUIPMENTS: 5.15.1 The voltmeters, Ammeters, Thermometer and Hydrometer etc. required the tests specified in this standard shall meet the requirements given in Clause 10.2 of IS: 8320. Where digital ammeter /voltmeter are used, the meter shall be capable of displaying up to two decimal in the range 0 to 99 volts and one decimal in 100 and above volts range. Use of digital ammeter/voltmeter is preferable for testing capable of displaying at least upto one decimal of the current to be measured data recorders shall be used for C10, Ah and Wh efficiency, ROC I & II and life cycle testing with continuous logging facility of voltage, current , AH input/output with reference to time. Manual recording is not permitted. 5.16 TEMPERATURE FOR TEST:- Unless otherwise specified the temperature for test shall be between 20 degree and 32 degree centigrade, unless it is unavoidable. 6.0 MARKING & WORKMANSHIP 6.1 For Hard Rubber Container:- Marking -Both the shorter or longer sides of such container shall have the following details embossed on the container:- a) Manufacturer's name or trade mark and place of manufacturing, b) Rating at 10hrs. discharge rate, and c) Specific gravity of the electrolyte in the fully charged condition at 27 deg. C. Note: STICKER not permitted on cells. 6.1.1 For plastic container: Marking - On the top lid or container wall such details embossed are required:

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a) Manufacturer's name or trade mark of manufacturing Both the shorter or longer sides of such container shall have the following detail stencil on the container, a) Manufacturer's name or trade mark b) Rating at 10 hrs. discharge rate and c) Specific gravity of the electrolyte in the fully charged condition at 27±2 deg. C d) Place of manufacturing Note: STICKER not permitted on cells 6.1.2 The year and month of manufacture shall be punched on the terminal lug base. 6.1.3 Manufacture name or trademark and rating of battery will be stenciled or embossed on the connector.or on lid in ppcp container if marking are not embossed in container Workmanship: The container shall be from any cracking or chipping or distortion and any sign of leakage or spillage 6.1.4 A yellow band of 25mm width shall be provided on both sides along the width of the cell for easy identification of low maintenance batteries. 6.2 Cells should be suitably packed to avoid damage due to rough handling in transit 7. MATERIAL AND COMPONENT SPECIFICATION VERIFICATI ON TEST: 7.1 The battery shall be examined in the dismantled condition to see that the manufacturing is to the approved outline and assembly drawing and the various components are conforming to the specification as detailed above. The samples of sealing compound, separator, container and electrolyte shall be taken at random from the manufacturing line and tested to see that they meet requirements of the relevant specifications. 8. MAINTENANCE TOOLS AND INSTRUCTIONS: A wall mounting type " Tool Board" of suitable material and protected against acid fumes shall be supplied along with each battery bank. The tool Board shall comprise:- i. One Syringe for adding or taking out electrolyte from the cells. ii. One syringe type hydrometer of requisite range for measuring the specific gravity of electrolyte in the cells. This shall be provided with a graduated scale, one division of which representing at the most 0.005 unit of specific gravity with accuracy of calibration not less than 0.005 units of specific gravity. iii. One cell-testing-voltmeter 0-3 volts of accuracy class 0.5 in accordance with IS: 1248-1968. The resistance of the Voltmeter shall be 1000 Ohms per Volt.

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iv. One thermometer with an appropriate scale for measuring temperature of electrolyte. One division of the graduated scale of the thermometer shall represent at the most 1deg. C, the accuracy of calibration being not less than 0.5 deg. C. 9. DRAWING 9.1 The manufacturer shall supply two sets of drawing in A4 size listed a below for approval while offering the cell for type testing. (a) Detail drawing with dimensions of front, top and side view of the cell. (b) Detail drawing of the container showing different sections with dimensions. (c) Part drawings with sectional details of - (1) Terminal Post (positive and negative) (2) Container lid (3) Pole + and - (4) Plates (+ve and -ve groups assembly) (5) Separator (6) Sealed float guide (7) Micro porous vent plug (8) Inter cell / unit and end cell connectors (9) General arrangements of drgs. of 56 cells set indicating connections from cell to cell. (10) Any other drgs. Considered relevant 10.0 For the purpose of the cells supplied against this approval, approval means the approval of general design features. Not with standing the approval, manufacture is wholly and completely responsible for performance, life and reliability of battery during service. 10.1 Before offering the battery for prototype testing, all relevant drawings as considered by the RDSO, shall have the approval of competent authority. The manufacturer shall produce only drawings approved by competent authority during the prototype inspection and shall not undertake any modification until such time battery under prototype testing is completed and the observations of RDSO are recorded. 10.1.1 After the prototype approval by RDSO of a batteries design etc, no design change shall be undertaken by manufacturer on prototype cells/ batteries without prior approval of RDSO, failing which the prototype approval may be with drawn by RDSO at any time. 10.2 Not withstanding the above recommendations , manufacturer is wholly and completely responsible for performance, life and reliability of battery during service, It is also subject to satisfactory compliance to the various requirements like

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satisfactory online performance, quality assurance plan as approved by RDSO, successful completion of contracts/ Purchase orders placed by Railway Board/Production Units/Railways etc. 10.3 All manufacturer are advised to ensure that the batteries mentioned in these recommendations, have valid type approval certificate failing which no further extension of approval may be granted by this office. The entire responsibility of the offering the batteries timely in advance to RDSO for type testing lies wholly on the manufacturer which may be noted. RDSO in no case shall be held responsible for reminding the firm in this connection. Application for revalidation of type approval certificate shall be made at least six months in advance prior to expiry of validity of earlier approval granted. 10.4 If considered necessary, RDSO may undertake re-testing of some or al prototype tests as per specifications at any time to ensure proper effective quality control being exercised by the manufacturer at different stages of manufacturing. 10.5 RDSO may, also, undertake some special tests associating manufacturers to validate the design changes for which all the necessary testing equipment / instruments etc. shall be arranged by the manufacturer free of cost. 10.6 DESIGN DOCUMENTS AND INSTRUCTIONS MANUAL: Following documents in the spiral bound form will be submitted to the RDSO. a) Two set of drgs. As per clause 9.0 of this specification before offering for type test for approval and one set for records (bound form) after completion of type tests. b) (i) In house test results as per appendix 'A' and 'B' shall be sent to RDSO before offering for type test. (ii) Type tests results obtained by testing authority. c) Instructions manual -Two copy of instruction manual with each lot to consignee and one copy to RDSO 11.0 Alternative superior designs can be considered provided necessary technical justifications with benefits is furnished for scrutiny. 12 AFTER SALES SERVICE 12.1 The successful tenderer shall make necessary arrangements for closely monitoring the performance of equipments through periodical (preferably once in two months during the warranty period) visits to the location where they have been erected / installed for observations and interaction with the operating and maintenance personnel of the Indian Railways. Arrangements shall also be made by the successful tenderer for emergency / standby spare parts being kept readily

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available to meet exigencies warranting replacement so as to keep the equipment in service with least down time. 12.2 The successful tenderer shall respond promptly and in a workman like manner to any call given by Indian Railways for any assistance by way of attending to failures. Investigation into the causes of failure including tests, if any, to be done and for such other items with a view to seeing that the equipment serves the purpose for which it is intended. Technical guidance to ensure proper operation and maintenance of the equipment shall be constantly rendered. 13. INFRA-STRUCTURE FOR QUALITY ASSURANCE 13.1 The firm/manufacturer shall have the infrastructure facilities like machinery and plants and testing equipment as per Appendix " E" of the Specification. The requirements are considered essential before considering a firm for approval for manufacture and supply of the battery to the Indian Railways. In addition to the above, the firms having valid ISO 9000 certificate accreditation or equivalent for ensuring conformance to the laid down Quality System requirements for design, manufacturing process, testing , quality control at different stages of manufacturing etc. shall only be considered. 14. INFRINGEMENT OF PATENT RIGHTS Indian Railways/RDSO shall not be responsible for infringement of patent rights arising due to similarity in design, manufacture process, use of components, use in design , development and manufacture of batteries and any other factor, which may cause such dispute. The responsibility to settle any dispute lies with the manufacturer.

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APPENDIX -'A' (Clause0.4)

SCHEDULE OF DESIGN PARTICULARS

The following particulars are required to be supplied by the manufacturer with the quotation: S. No. DESCRIPTION PARTICULARS TO BE FILLED IN 1. Make ……………………. 2. Type of unit ……………………. 3. Manufacturers nomenclature ……………………. 4. Overall dimensions of unit ……………………. (length x width x height) 5. Mass per unit with acid ……………………. 6. Cell container material ……………………. 7. Type of positive plates ……………………. 8. Type of negative plates ……………………. 9. Separators ……………………. 10. Maximum electrolyte temp. ……………………. That the cell / battery withstand Without any damage a) Continuously …………………….deg C b) For a short period …………………….deg C 11. Electrolyte height above …………………….mm the top of separators 12. Electrolyte height below …………………….mm the bottom plates 13. Quantity of electrolyte ……………………. Liters per cell 14. Sp. Gr. of electrolyte for initial ……………………. filling at 27 deg. C 15. Details of initial treatment ……………………. Recommended 16. Material of terminal and ……………………. inter - cell connectors 17. Normal Charging Rate …………………….Amps 18. Frequency of topping up …………………….months 19. Inter cell connector size …………………….sq., mm.

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APPENDIX 'B' (Clause 0.4)

SCHEDULE OF PERFORMANCE S. No. DESCRIPTION PARTICULARS TO BE FILLED IN

Batteries offered according to this standard shall be covered by a type approval certificate from an appropriate authority. All variations in the design

shall be covered by a separate type approval certificate. Following particulars regarding the type tests shall be supplied

by the manufacturer along with the certificate

against any quotation or tender.

1. C-10 Ampere -hour capacity (actual /declared) …………………….Ah 2. Ampere hour efficency …………………….percent 3. Watt hour efficieny …………………….percent 4. Retention of charge …………………….percent 5. Life …………………….units 6. torage …………………….Ah

7. Rise in electrolyte temp above the ……………….deg. Cent

ambient air temp. when charged from dully discharged to fully charged conditions at normal rate.

8. Charge and discharge curves with voltage ……………………. Versus time showing the performance of the Cell for discharge at 10 hours rate and charge at Normal rate

9. Loss of water ………………..gm/Ah

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APPENDIX"C" SEQUENCE OF TYPE TESTING

-------------------------------------------------------------------------------------------------------- TEST SAMPLE NUMBER 1 2 3 4 5 6 7 8 9 -------------------------------------------------------------------------------------------------------- a(*) Checking of dimensions, x x x x x x x x x mass, markings and workmanship b. Capacity at 10hrs. rate x x x x x x - - - c. Material and component - - - - - - - - x specification verification test d. Air Pressure - - - - - - x x - e Storage - - - - - - x x - f. Life - - x x - - - - - g. Watt hour and Ampere - - - - x x - - - hour efficiency h. Retention of Charge - - - - x x - - - i. Equilibrium float current x x - - - - - - - j. Water loss x x - - - - - - - k. Sealing of container x x with lid (*) Mass to be checked for sample numbers 1 to 6 (x) Samples to be subjected for tests NOTE: The cell of new design shall be prototype tested for which samples offered by the manufacturer shall be accepted. The cells shall be re-type tested every 5 year for revalidation and the samples shall be drawn from mass production at random. In case of unsatisfactory performance of cells in field, re-type testing can also be done earlier at the discretion of the approving authority.

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APPENDIX "D" (Clause 5.5.5)

SAMPLING PROCEDURE FOR ACCEPTANCE TESTS D.1 LOT D.1.1 In the consignment, all the cells of the same rating manufactured from the same material under similar conditions of production shall be grouped together to constitute a lot. D.1.2 These cells in the sample shall be drawn from the lot at random. For the purpose of random selection, reference may be made to IS: 4905- 1968 D.2 SAMPLE SIZE AND CRITERIA FOR CONFORMITY D.2.1 The acceptance tests shall be conducted on minimum two samples upto a maximum of 1 percent of each type in a lot, the samples being drawn at random by the purchasing or inspecting authority as specified in clause 5.1.3.1 Appendix 'G' in Amendment NO. 1 of IS:6848-79 latest D.2.2 Criteria for Acceptance if any of the samples cells fail in any of the acceptance test, twice the original number of samples shall be taken and subjected to all the acceptance tests. If there is failure in re-test, the lot may be rejected.

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APPENDIX "E"

LSIT OF MACHINERIES AND PLANTS FOR MANUFACTURE OF L OW

MAINTENANCE LEAD ACID STORAGE CELL ESSENTIAL MANUFACTURING FACILITIES

1. Lead antimony alloying plant to have alloy with different antimony percentages 2. Lead oxide manufacturing mill (a) Lead Peroxide manufacturing Plant. 3. Pressure die-casting machines for Positive /Negative grids (Hand molding process

not permitted) (a) Die- casting machines for terminal post, inter cell connectors , poles etc,. (Hand molding process not permitted)

4. Automatic pasting plant for negative plates (Hand pasting process not permitted) (a) Automatic paste mixing plant (Manually not permitted)

5 Vibration plant for filling of positive tubular plates 6 . Positive tube bag manufacturing plant 7. Separator manufacturing plant 8. Container manufacturing plant with computer controlled rubber mixing for making

container 9 Plate formation plant 10. Jigs and fixtures to make groups of positive and negative plates 11. Bitumen compound sealing plant with thermostat 12. Chemical Laboratory to test various chemical ingredients. 13 Gas burners set for assembly of positive and negative group plates for battery . 14. Distilled water manufacturing plant 15 Container top lid- manufacturing plant 16 Container and top lid manufacturing plant for PPCP material 17. Heat sealing plant for PPCP cells 18. Compressor with dryer 19. Humidity chamber 20. ISO 9000 certificate ADDITIONAL PLANT AND MACHINERY (a) Air pollution control system (b) Water effluent plant (c) Water sera beer for formation room (d) Fork lift (e) Pallet truck (f) Formation rectifier (g) DG Sets

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ESSENTIAL LIST OF TEST EQUIPMENT

1. C10 test conducted by computerized control battery charging /discharging equipment with monitoring and recording system (Manually not permitted)

2 Fully computerized control life cycle testers with logging , monitoring and recording system (Recording time, voltage, min. 6 channels , current m, temp , Ah, Wh, mode and cycle step)

3. Temperature controlled test room 4 Carbon pile loads of different capacity 5. Container testing facilities as per IS -1146 (i.e. High Voltage tester, Plastic yield test apparatus, Electro magnetic ball drop test

apparatus Izod impact tester, tensile testing machine, digital and chemical testing arrangements etc. )

6. Digital ammeter, voltmeter and thermometer of different ranges 7. Measurement facility for pore size of separators 8. Battery/cell internal resistance meter 9. Sulphuric acid and distilled water testing facilities as per IS specifications 10. Multimeter digital (Min. DCV 1000 V, ACV -750 V DC 10A, R- 2 mega Ohm)

ADDITIONAL LIST OF TEST EQUIPMENT

1. Thermostatically control rolled tank for life cycle units. 2. Separator testing apparatus as per IS 6071 3. Bitumen sealing compound testing apparatus as per IS 3116 4. Distilled water testing arrangements as per IS 1069 5. Microporous vent plug testing arrangement (i.e. Electromagnetic ball drop apparatus,

weighting digital top pan balance capacity 100 gms +- 0.05 gms, fire retardant test apparatus, permeability test apparatus etc. )

6. Heating apparatus 7. Electronic Balances(capacity 50gms with decimal second digit) 8. Shore hardness meter 9. Manometer 10. Air pressure tests arrangements 11. Polarity testing arrangements 12. Short circuit testing arrangements.

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SPECIFICATION FOR

CHARGER FOR 110 V, 40 Ah AND 110 V, 200 Ah MAINTENANCE FREE, SEALED, LEAD ACID BATTERY.

No. ETI / PSI / 158 (08 / 96)

487




SPECIFICATION

FOR

CHARGER FOR 110 V, 40 Ah AND 110 V, 200 Ah

MAINTENANCE FREE, SEALED, LEAD ACID BATTERY.

ISSUED BY



488


RESEARCH, DESIGN & STANDARDS ORGANISATION MANAK NAGAR, LUCKNOW – 226 011.


SPECIFICATION FOR CHARGER FOR 110 V, 40 Ah AND 110 V, 200 Ah

MAINTENANCE FREE, SEALED, LEAD ACID BATTERY. 1.0 SCOPE 1.1 This specification applies to battery chargers for charging (i) 110 V, 40 Ah and (ii)

110 V, 200 Ah maintenance free, sealed type lead acid battery installed at unattended 25 kV traction switching stations (SPs and SSPs), traction substations (TSSs) and at remote control centre (RCC). The remote control centres are, however, attended.

1.2 The battery charger shall be complete with all parts and accessories necessary for

their efficient operation. All such parts and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not.

1.3 This specification has been updated incorporating the corrections / additions as

circulated under A/C slip – 1 (Sep. 95) and – 2 (Feb. 96). 2 SERVICE CONDITIONS 2.1 The battery charger are intended for use in moist tropical climate in India, where

the maximum temperature may reach 45 deg. Celsius in shade, the daily maximum average ambient reaching 35 deg. Celsius, with a relative humidity reaching up to 100 %.

2.2 The battery chargers shall be suitable for operation of 240 V, 50 Hz. Single phase

power supply obtained from a 25 kV / 240 V LT supply transformer at the TSS / SP / SSP. The primary of the LT supply transformer is connected to 25 kV bus bar at one end and to earth at the other. The 240 V supply at the TSS / SP / SSP is subject to fluctuations of voltage between 180 and 265 V.

2.3 The battery charger is required for installation in control cubicles of unattended 25 kV switching stations / TSS or in equipment room at RCC to charge the maintenance free battery at a constant voltage of 121.5 V for 54 cells configuration @ 2.25 V / cell. A provision has also to be made to charge the battery at a constant voltage of 124.2 V. under boost charging mode at the rate of 2.30 V / cell.

2.4 The battery charger shall be subjected to vibrations on account of trains running on

nearby tracks. The amplitude of these vibrations which occur with rapidly varying

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time periods in the range of 30 to 70 ms lies in the range of 30 to 150 microns at present, with the instantaneous peak going upto 350 microns. These vibrations may become more severe as the speeds and loads of trains increase in future.

GOVERNING SPECIFICATION 3.1 The battery charger and its parts and accessories shall, unless otherwise specified,

conform to the following standards (latest version) which shall be applied in the manner, altered, amended or supplemented by this specification and the Indian Electricity Rules, where applicable:

I) Mono-crystalline semiconductor IS : 4540 – 1968 rectifier assemblies and equipment. IS : 6619 – 1972 II) Rectifier transformer IS : 2026 – 1977 III) Mono-crystalline semiconductor IS : 3895 – 1966

rectifier cells and stacks. IV) Electrical indicating instruments IS : 1248 – 1968 V) Miniature air break circuit breaker IS : 8828 – 1978 3.2 Any deviation from this specification calculated to improve the performance, utility

and efficiency of the equipment, proposed by the tenderer, will be given due consideration, provided full particulars with justification thereof, are furnished. In such a case, the tenderer shall quote according to this specification and the deviations proposed by him shall be quoted as an alternative(s).

4. RATING AND OTHER PARTICULARS: 4.1 BATTERY CHARGER FOR 40 Ah BATTERY: 4.1.1 The battery charger shall be designed for following rating and other particulars: 4.1.2 Type Constant voltage current limiting type,

preferably with half controlled SCR diode bridge, suitable for floor mounting.

4.1.3 Input voltage 240 V, 50 Hz. ac, subject to variation from

180 to 260 V. 4.1.4 Output voltage to battery (a) Float Mode : 121.5 V for 54 cell for

battery charging. configuration @ 2.25 V / Cell. (b) Boost Mode : 124.2 V for 54 cell

490

configuration @ 2.30 V / Cell. Under both float and boost mode the voltage shall be manually adjustable between 115 V to 127 V.

4.1.5 Output voltage regulation +/- 1% for 0-110 % load on the charger and simultaneous variation in ac input from 180 V to 265 V and frequency variation of +/- 3%.

4.1.6 Output current “ At SP / SSP : 9A (max), including 5A for

load and 4A for charging battery”. 4.1.7 Charging characteristics Constant voltage current limited charger,

current dropping on charging of batteries. 4.2 BATTERY CHARGER FOR 200 Ah BATTERY: 4.2.1 The battery charger shall be designed for following rating and other particulars: 4.2.2 Type Constant voltage type, suitable for floor

mounting. 4.2.3 Input voltage 240 V, 50 Hz. ac, subject to variation from

180 to 265 V. 4.2.4 Output voltage to battery 124 and 136 V

for battery charging. ( to be adjusted manually )

4.2.5 Output voltage regulation +/- 1% for 0-110 % load on the charger and simultaneous variation in ac input from 180 V to 265 V and frequency variation of +/- 3%.

4.2.6 Output current At RCC / TSS : 40A (max), including 20A

for load and 20A for charging the batteries. 4.2.7 Charging characteristics Constant voltage, Current dropping on

charging of battery. 4.3 RIPPLE CONTENT: 4.3.1 The battery charger shall be equipped with suitable filter circuits on the output side

to reduce the ripple factor of output voltage to less than 3 % at full load, when measured across a resistance load. The ripple factor is defined as the ratio of superimposed ac rms voltage to average dc voltage.

491

4.3.2 The chokes and magnetic components wherever used, shall have copper winding and shall be vacuum impregnated.

4.4 The battery charger shall be provided with a suitable control circuit to limit the

charging current. The charger should have provision to run in auto mode where it automatically go to boost mode when battery draws more than 6 % Ah capacity current for more than 30 S. Similarly if the battery current falls below 3 % Ah capacity for more than 30 S, the battery charger should automatically work in the float mode.

4.5 ANNUNCIATIONS AND INDICATIONS AND CONTROLS: 4.5.1 The following annunciations, indications, indicating instruments and controls along

with appropriate inscription labels shall be provided on the front panel of the charger:

A) INDICATIONS:

i) AC ON Red LED ii) OUTPUT ON Red LED iii) BATTERY ON FLOAT CHARGE Amber LED iv) BATTERY ON BOOST CHARGE Red LED

B) CONTROLS:

i) Input ON miniature circuit breaker (MCB). ii) Output ON miniature circuit breaker (MCB). iii) Charge selection adjuster 115 / 127 V. iv) A selector switch may be provided to read either charger output

current or battery charging / discharging current, on a centre zero Ammeter.

C) INDICATING INSTRUMENTS:

i) ac input Voltmeter 0-300 V ii) dc output Voltmeter 0-150 V

iii) Charger output Ammeter (a) 10-0-10 A (for 40 Ah

Battery charger) (b) 50-0-50A (for 200 Ah

Battery charger)

iv) Battery input / output Ammeter (a) 0-5A/10 A (for 40 Ah

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Battery charger)

(b) 0-20 A/ 40 A (for 200 Ah Battery charger)

D) PROTECTIONS:

i) Fuse for ac input supply. ii) Fuse for dc output to battery. iii) Fuse for dc output to load. iv) Protection against Reserve Polarity. v) Battery over voltage protection (electronic control preferred)

NOTE : A separate battery input / output ammeter as asked for against C (iv) may not be provided, in case a selector switch for the purpose, as mentioned under 4.5.1 (B) (iv) have been provided.

5. CONSTRUCTION: 5.1 All the parts and accessories of the battery charger shall be housed a suitable

cubical fabricated from angle iron frame work fitted with mild steel sheet panels of thickness not less than 1.6 mm. The side and rear panel shall be provided with louvers to provide adequate ventilation. Wire mesh with opening not more than 3 mm shall be provided on the inner side of the louvers for protection against entry of lizards, vermin.

5.2 The battery charger cubical shall be treated with a suitable rust resisting primer

paint applied on the interior and exterior surfaces followed by an application of two coats of enamel paint evenly sprayed to present a fine appearance. The colour of the enamel paint applied on exterior surfaces shall be “Dark Admiralty Grey”, shade 632 of IS: 5 – 1961, and the interior surface shall be finished with white shade.

5.3 The charger shall be of robust construction. The components of the battery charger

shall be appropriately mounted and identified with identification labels. The layout of major components shall permit easy access for maintenance. The assembly shall be such that it will not be affected adversely by the vibrations induced from nearby railway tracks. The clearances and the creepage distances shall be in accordance with clause 4 of IS: 6619 – 1972. The noise level shall be kept to the minimum.

5.4 The rectifier shall be of full wave half controlled bridge connection, using silicon

diodes along with SCRs of liberal rating. The rectifier shall be suitably protected against overloading due to short time heavy currents drawn during closing of the circuit breakers, short circuits, over voltages and against inrush currents when charging fully discharged batteries and also protected against reverse polarity of battery.

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5.5 The switches, meters and fuses shall be flush mounted on the front panel and shall be of reputed make. These shall conform to relevant Indian Standard specifications.

5.6 The volt meters and ammeters shall be of flush mounted type of accuracy class 1.5

as per IS: 1248 – 1968 and shall have scale length of not less than 72 mm. 5.7 Wiring 5.7.1 The wiring inside the charger shall be with 1100 V grade PVC insulated single

core, tinned annealed stranded copper conductor for service in extremely tropical climate. The PVC wires shall conform to IS: 694. The wiring shall also not be prone to attack by vermin. For wiring, PVC insulated copper wires of adequate cross section shall be used, having rated current carrying capacity of not less than 3 times the current it is designed to carry at full load.

5.7.2 The terminal ends of all wires shall be provided with numbered interlock type

ferrules which shall be of PVC or other durable material with markings either engraved or punched so to be indelible. The ferrules shall be of white colour with black lettering thereon.

5.8 The ac input and the dc output terminals shall be of robust design and shall be

suitable for PVC copper cable connections. The polarity of output dc terminals for battery connections and load connections shall be clearly marked.

6. ACCESSORIES

The following fittings and accessories shall be provided on the battery charger:

6.1 Rating and diagram plate 6.2 Two earthing terminal suitable for taking 8 SWG GI wires. 6.3 PVC insulated PVC sheathed 1100 V grade 3 core cable with copper conductors

having a minimum cross section of 2.5 and conforming to IS: 694 – 1977 of 2 meter length fitted with suitable 3 pin plug of 15 A rating for connection to 240 V ac supply for 40 Ah battery. In case of the chargers for 200 Ah battery, a suitable terminal block shall be provided to connect 240 V ac supply, with suitable 3 core cable with copper conductors having minimum 6 sq.mm. cross section of 3 meter length.

7. DRAWINGS 7.1 The successful tenderer shall submit the following detailed dimensioned drawings

along with three prints of each as per Railway standards in size of 210 mm x 297 mm or any integral multiple thereof for approval. A format of title sheet to be

494

adopted by the successful tenderer / manufacturer for preparation of the drawings is attached at Annexure 2.

1. Outline general arrangement drawing (in three views) along with

mounting dimensions. 2. Schematic diagram of connections along with technical details of

components.

3. Cross-section views (showing location of major components).

4. Schedule of guaranteed and other technical particulars.

After approval six copies of approved drawings along with 2 sets of reproducible copies shall be supplied to the purchaser.

7.2 Successful tenderer shall also be required to furnish the design calculations for the rectifier transformer ratings, rectifier ratings and filter circuits for approval by the purchaser.

7.3 The provisionally approved drawings shall be modified, if need be, as a result

of changes necessitated during type testing or as desired by the purchaser. The modification shall be first got approved by the purchaser / Director General (Traction Installation), Research Designs and Standards Organisation, (DG/TI/RDSO), Lucknow and then incorporated in the drawing and each such modification shall be got signed by the authority concerned on the drawings. If there are no modifications at all, the provisionally approved drawings shall be finally approved.

7.4 Six copies of approved drawings along with two sets of reproducibles shall be

sent to each consignee(s), as indicated in the purchase order. Besides two copies of drawings along with one set of reproducibles shall be supplied to DG (TI), RDSO, Lucknow.

7.5 The successful tenderer shall also be required to supply atleast 6 copies of the

Installation and Maintenance manuals for battery charger to each consignee and two copies to DG (TI), RDSO, Lucknow.

8. TESTING OF BATTERY CHARGER 8.0 General In the event of the tests not being carried through to completion at one stretch

for any reason attributable to the successful tenderer / manufacturer and it is required for the representative of the Purchaser / Director General (Traction Installation), Research Designs & Standards Organisation, (DG/TI/RDSO), Manak Nagar, Lucknow, to go again or more number of times to the works of

495

the successful tenderer / manufacturer or other place(s) for continuing and/or completing the tests on the prototype(s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser / DG (TI), RDSO, Lucknow, the costs for the representative having to visit the works or other place(s) for the tests more than once. The costs as claimed by the Purchaser / DG (TI), RDSO, Lucknow, shall be paid through a demand draft to the concerned Accounts Officer of the Purchaser / DG (TI), RDSO, Lucknow, as shall be advised to the successful tenderer / manufacturer.

8.1 Type Tests The following type tests shall be carried out on the prototype at the works of

the successful tenderer / manufacturer or at any reputed laboratory in the presence of the representatives of the Purchaser / DG (TI), RDSO, Lucknow, and in accordance with the relevant specifications – altered, amended or supplemented by this specification.

8.1.1 Tests on complete charger.

8.1.2 Visual Inspection

The proper layout, component mounting, identification labels, connections and construction shall be checked.

8.1.3 No load test 8.1.4 The test shall be carried out by applying input voltage varying from 180 V to

265 V (in steps of 180 V, 210 V, 240 V & 265 V). The dc output voltage shall be manually adjusted between 115 V and 127 V, (in steps of 115 V, 120 V, 124 V & 127 V) at each step of ac input voltage (indicated above). The no load ac input current shall be recorded in each case.

8.1.5 Load test with resistive load

The test shall be carried out at different ac input voltages from 180 V to 265 V in steps of 180 V, 210 V, 240 V and 265 V. For each of these input voltages, the output voltage shall be set at 115 V, 120 V, 124 V and 127 V. then for each case, the load shall varied from 0% to 100% of rated load with the help of resistance. The dc output voltage shall not decrease by more than 1% from the set value, by variation of load from 0% to 100%.

8.1.6 Measurement of ripple content

Ripple voltage on d.c. side shall be measured during the load test (Cl.8.2.2.3) and the percentage ripple content shall be calculated which shall not exceed as specified in clause 4.

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Efficiency test

This test can be combined with no load test and load test for which details have been indicated in clause 8.2.2.2 and 8.2.2.3 respectively. For this test, input current, voltage and power on the ac side shall be recorded at the minimum and maximum output voltages. The efficiency and the power factor shall then be computed from the test results.

8.1.8 Temperature rise test

The test shall be carried out at output voltage set to maximum. A suitable resistive load shall be connected across the output and load current shall be adjusted to the maximum rated current. The ambient temperature, surface temperature of transformer, winding chokes and diode base etc. shall be recorded every half an hour till such time the temperature is stabilised (i.e. the temperature do not rise by more than 1 degree celcius between consecutive hourly readings). The temperature rise of the transformer winding and choke measured by resistance method shall not exceed 50 Deg. C. for class A and 90 Deg. C. for class F insulation. The SCR and diode base temperature rise shall be within the prescribed values recommended by the manufacturer.

8.2. Insulation Resistance Test Insulation resistance shall be measured by using 1000 V dc megger between: a) ac line lead to earth b) dc output terminals to earth c) ac line lead and output terminals. The values shall be measured before and after the high voltage withstand test and there shall not be any appreciable change in the measured values.

8.2.1 Power frequency voltage withstand test The charger shall successfully withstand the test voltage of 2000 V ac rms 50 Hz applied for one minute between: 1) dc output terminals and earth 2) ac input terminals and earth 3) dc output terminals and ac line load

8.2.2 Test on rectifier transformer

8.2.3 Measurement of resistance Resistance of primary and secondary windings, shall be measured, preferably with a bridge instrument, at ambient temperature and recorded.

497

8.2.3.1 Open circuit test Rated primary voltage shall be applied to the primary of the transformer and the primary and the secondary voltages and power drawn at no load shall be recorded.

8.2.3.2 Short circuit test With the secondary winding short circuited, suitable voltage shall be applied to the primary to pass the maximum rated current in the primary and the primary voltage, current and power shall be recorded and the full load losses calculated.

8.2.3.3 Insulation resistance test With the secondary winding short circuited, suitable voltage shall be applied to the primary to pass the maximum rated current in the primary and the primary voltage, current and power shall be recorded and the full load losses calculated.

8.2.3.4 Insulation resistance test Insulation resistance shall be measured by using 1000 V dc megger between:

a) Primary winding and earth b) Secondary winding and earth c) Primary winding and Secondary winding (s). The values shall be measured before and after the high voltage withstand test and there shall not be any appreciable change in the measured values.

8.2.3.5 Power frequency voltage withstand test

The rectifier transformer shall successfully withstand the test voltage of 2000 V ac rms 50 Hz applied for one minute between primary and secondary windings combined together and core.

8.2.4 If prototype of a battery charger conforming to this specification has already been approved in connection with the previous supplies to the Indian Railways, fresh prototype testing may be waived, if it has passed the prototype test earlier and no changes in the design or material used, have been made.

8.3 Routine Tests The following routine tests shall be carried out on the battery charger: 8.3.1 Visual inspection

The proper layout, component mounting, identification labels, wiring, connections, workmanship, quality of painting, surface finish and construction shall be checked.

8.3.2 No load test The test shall be carried out in accordance with the clause 8.2.2.2 except that the tests shall be carried out only at the rated input voltage of 240 V ac.

8.3.3 Load test with resistive load The test shall be carried out in accordance with the clause 8.2.2.3 except that the tests shall be carried out only at the rated input voltage of 240 V ac.

498

8.3.4 Insulation resistance test

The test shall be carried out in accordance with the clause 8.2.3.4.

8.3.5 Power frequency voltage withstand test The test shall be carried out in accordance with the clause 8.2.3.5.

9. INFORMATION TO BE GIVEN BY THE TENDERER 9.1 The tenderer shall furnish along with his offer, in the proforma at Annexure-1, the

“schedule of guaranteed performance, technical and other particulars” (SOGP) for the battery charger. The particulars shall be correct and complete in all respects. If there is any entry like “shall be furnished later” or a blank against any item, the offer is not likely to be considered as the evaluation of the offer is rendered difficult and can not be compared with other offers, if any.

9.2 The tenderer shall specifically indicate in a “statement of compliance” attached

with the offer his compliance with each and every clause of this specification, in case the tenderer wishes to deviate from any clause of this specification he may do so giving reference to the clause(s) with the reason / justification for the deviation. This shall be in the form of a separate statement called the “statement of deviation”. If there is no deviation at all, a separate “Nil” “statement of deviation” shall be attached with the offer. If the “statement of compliance” and not likely to be considered for the reason that it is incomplete offer which can not be properly evaluated and compared with other offers, if any.

10. AFTER SALES SERVICE 10.1 The successful tenderer shall make necessary arrangements for closely monitoring

the performance of the equipment through periodical (preferably once in two months during the warranty period) visits to the location where they have been erected / installed for observations and interaction with the operating and maintenance personnel of the Indian Railways. Arrangements shall also be made by the successful tenderer for emergency / standby spare parts being kept readily available to meet exigencies warranting replacement so as to keep the equipment in service with least down time.

10.2 The successful tenderer shall respond promptly and in a workman like manner to

any call given by Indian Railways for any assistance by way of attending to failures, investigation into the causes of failures including tests, if any, to be done and such other items with a view to seeing that the equipment serves the purpose for which it is intended. Besides technical guidance to ensure proper operation and maintenance of the equipment shall be constantly rendered.

499

11 WARRANTY

11.1 The successful tenderer / manufacturer shall warrant that all equipment shall be ree

from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally acceptable standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

11.2 This warranty shall survive inspection of, payment for the acceptance of the

equipment, but shall expire 24 (Twenty four) months after the delivery at ultimate destination, or 18 (Eighteen) months from the date of commissioning and proving test of the equipment at ultimate destination, whichever period expires first except of complaints, defects and/or claims months of the expiry of such date. Any approval or acceptance of the Purchaser of the equipment shall not in any way limit the successful tenderer / manufacturer’s liability.

11.3 The successful tenderer / manufacturer’s liability in respect of any complaint,

defects and/or claims shall be limited to the furnishing and installation of replacement parts free of any charge or the repair of the defective parts only to the extent that such replacement of repairs attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer / manufacture within 3 (Three) months of their being first discovered during the warranty period or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned.

11.4 The successful tenderer / manufacture shall, if required, replace or repair the

equipment of such portion thereof as is rejected by the Purhaser free of cost at the ultimate tenderer / manufacture shall pay to the Purchaser value thereof at the Contract Price or in the absence of such price at a price decided by the purchaser and such other expenditure and damages as may arise by reason of the breach of the conditions herein specified.

11.5 All replacements and repairs that the Purchaser shall call upon the successful

tenderer / manufacture to deliver to perform under this warranty shall be delivered and performed by the successful tenderer / manufacture, promptly and satisfactorily and in any case within 2 (Two) months of the date of advice to this effect.

11.6 If the successful tenderer / manufacture so desires, the parts that are removed may

be taken over by him or his representative for disposal as he deems fit at the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.

500

11.7 The warranty therein contained shall not apply to any material which shall have

been repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer / manufacture, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

11.8 The decision of the Purchaser in regard to successful tenderer / manufacture’s


501

ANNEXURE –I


SCHEDULE OF GUARANTEED PERFORMANCE, TECHNICAL AND OTHER PARTICULARS.

S.No

Description Unit of measurement



3. Standard Governing Specification.


5. Designed capacity of charger for charging battery of.

Ah.

6. Rated input voltage

V ac

7. Output voltage. I) To battery: II) To load:

V dc V dc

8. Output voltage regulation from 0-110% load: a) To battery: b) To load:

% +/- % +/-

9. Maximum output current of charger

A

10. Declared values. a) No load loss of complete charger b) Full load loss of complete charger on c) Overall efficiency of charger at full load d) Variation in maximum charging current to

battery with 10% increase in supply voltage

e) Percentage ripple content in output voltage at full load with resistance load connected.

mA A

502

11. Size and type of 240 V ac incoming lead.

12. Thickness of sheet steel for charger cubicle.

“mm”

13. Overall dimensions: i) Height ii) Width iii) Depth

mm mm mm

14. Total weight.

kg

15. Rectifier transformer particulars: a) Name of manufacturer b) Governing specification

i) Rated input voltage ii) Taps provided for variation in

input voltage. iii) Rated kVA

c) Type of winding. d) Type of impregnation of. e) Class of insulation.

V ac kVA

503

RDSO Specification No.ETI / PSI /158 (08/96) for Battery Charger The following amendments are made in addition to the addendum and corrigendum slips issued to the specification : Sl.No. Para No. Amendment 1. 7.4 Delete the second sentence in the para. 2. 7.5 Delete the words “Two copies to DG(TI),RDSO, Lucknow “at the end of para. 3. 11.2 The para is modified as given below :

“The warranty shall be 36 (Thirty six) months from the date of delivery of the equipment at the ultimate destination or 24 (twenty four) month from the date of commissioning of the equipment at the ultimate destination, whichever occurs first”.

4. 11.3 In Line 8, delete the words at the end of the para starting with “Or at the option ……………..as hereafter mentioned”

504


SPECIFICATION FOR

OUTDOOR CIRCUIT BREAKER FOR

RAILWAY AC TRACTION SUB - STATIONS

No. TI / SPC / PSI / CB / 0000

505

Specification No. TI/SPC/PSI/CB/0000



SPECIFICATION

FOR

OUTDOOR CIRCUIT BREAKER

FOR RAILWAY ac TRACTION

SUB - STATIONS

ISSUED BY



506

CIRCUIT BREAKER for

Railway ac Traction Sub-Station 1. Scope 1.1 This specification applies to outdoor type single pole, double pole & triple pole SF6

and vacuum circuit breaker for use in unattended / attended Railway Traction Sub-Stations in any part of India for controlling power supply to the 25 kV ac 50 Hz. single phase traction overhead equipment (OHE). This specification supersedes Specification No. ETI/PSI/93 (5/94), ETI/PSI46 (9/94), ETI/PSI/131 (8/89) and ETI/PSI/116 (4/88) . This specification shall also apply for primary side 22 kV and 100 kV two pole vacuum and SF6 circuit breaker to be used in Mumbai area of Central and Western railway ac traction system.

1.2 The CB shall be complete with all parts, fittings SF6 gas for the first filling, Vacuum

bottle as the case may be and accessories necessary for its efficient operation, including mounting frame work of steel. All such parts, fittings and accessories shall be deemed to be within the scope of this specification, whether specifically mentioned or not. The CB shall be of proven design.

1.3 The CB shall be erected by the Purchaser / Indian Railways. However, in case a

defect / deficiency is noticed, the manufacturer/ successful tenderer will have to depute his engineer for necessary remedial action without any cost to the Railways. In all the cases in which an order is placed either on new manufacturer or for a new type /design of the CB, the services of manufacturer’s engineer shall be made available free of cost during the erection and proving /pre-commissioning test for the first order or for the first order of their CB. For this purpose, prior intimation regarding the date and the location shall be given by the purchaser to the successful tenderer / manufacturer.

2.0 Governing Specification

2.1 The CB shall unless otherwise specified therein, conform to the “IEC 60056 / 1987,

High voltage ac circuit breaker” and the Indian Electricity Rules, wherever applicable.

2.1.1 In the preparation of this specification, assistance has been derived from the

following Standards : (1) IEC : 60056 (1987) : High voltage alternating current circuit breakers (2) IEC : 376 (1971) : Specification and acceptance of new sulphur

hexafluride gas.

507

(3) IEC : 694 (1980) : Common clauses for high voltage Switchgear and

Control gear standards. (4) IS : 456 (1978) : Code of Practice for plain and reinforced concrete. (5) IS : 996 (1979) : Specification for single phase small ac and

universal electric motors. (6) IS : 2099 (1973) : Specification for bushing for alternating voltages

above 1000 V. (7) IS : 2544 (1979) : Specification for porcelain post insulators for systems with nominal voltages greater than 1000 V. (8) IS : 5561 (1978) : Specification for electric power connectors. (9) IS : 5621 (1980) : Specification for hollow insulators for use in

electric equipment. (10) IS : 6875 (Pt. 1-1973) : Specification for control switches ( switching

device for control and auxiliary circuits including contactor relays) – for voltages up to and including 1000 V ac and 1200 V dc – General requirements and tests.

(11) IS : 7906 (Pt. I-1976) : Specification for helical compression springs. (12) IS : 7907 (Pt. I-1976) : Specification for helical extension springs. (13) IS : 13118 (1991) : Specification for high voltage alternating current

circuit breakers. (14) IS : 1554 ( Pt. V – 1988) : Specification for PVC insulated (heavy duty )

electrical cables for working voltage up to & including 1100 V.

(15) IS : 808 (1989) : Dimensions for hot rolled steel beam, column, channel & angle sections. (16) IS : 2147 (1962) : Degree of protection provided by enclosures for low

voltage switchgear.

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(17) RDSO Specification No. ETI/OHE/13 (4/84) : For hot dip galvanization. (18) RDSO Specification No. ETI/OHE/18 (4/84) : For steel and stainless steel bolts,

nuts and washers. (19) RDSO Specification No. M&C/PCN -102/86 : For Epoxy bases zinc phosphate

primer ( two pack). (20) RDSO Specification No. M&C/CPN -110/88 : For Aluminium paints based on

Polyurethane. (21) AC Traction manual (Issued in 1994) 2.2 Any deviation from this specification as proposed by the tenderer to improve upon

the performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of deviation with justification thereof are furnished, subject to approval of RDSO. In case of any contradiction between the provisions of the Indian Standards Specification/IEC standard and this specification, the latter shall prevail.

2.3 This specification is framed merging the four RDSO Specification Nos.(i)

ETI/PSI/93(5/94), (ii) ETI/PSI/46 (9/94), (iii) ETI/PSI/131 (8/89) and (iv) ETI/PSI/116 (4/98) for 25 kV ac 50Hz single pole SF6 circuit breaker, 25 kV ac 50Hz single pole vacuum circuit breaker, 25 kV ac 50Hz double pole SF6 gas circuit breaker for 2 x 25 kV AT feeding system and 220 kV/132 kV / 110 kV / 66 kV ac 50 Hz double pole and triple pole outdoor SF6 circuit breaker respectively. Hence the firms approved as per any of the above specifications (four), shall be considered as approved as per this specification also. The changes are only in respect of operating sequence for 25kV CB which has been changed from O-0. 3s-CO-30s-CO to O-0.3s-CO-15s-CO, ground clearances and supervision of erection and commissioning which shall be incorporated in their design at the time of offering the equipment as per this specification. Apart from above, his specification also includes technical details and others for 22 kV and 100kV two pole vacuum and SF6 circuit breaker to be used in ac traction system of Mumbai area.

3.0 Traction Power Supply 3.1 General Scheme 3.1.1 The single phase 50Hz power supply for railway traction at 25 kV is obtained from

220/132/110/100/66/22 kV three phase grid system through step down / step up single phase power transformer, the primary winding of which is connected to two of the phases of the three phase effectively earthed transmission line network of the State Electricity Board. The primary voltage of the traction transformer being 220 kV or 132 kV or 110 kV or 100 kV or 66kV or 22 kV and no load secondary voltage being 27 kV. In order to reduce the imbalance on the three-phase grid system, the two phases of the three phase transmission line are tapped in a cyclic

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order for feeding the successive traction sub-stations (TSS). The distance between adjacent TSS is normally between 50 km and 80 km depending upon density of traffic gradients in the section and other factors.

3.1.2 One terminal of the 25 kV secondary winding of the traction transformer is

connected to the OHE through circuit breaker / interrupters and the other terminal is solidly earthed and connected to the appropriate traction rail (s). The current flows through the OHE, to the locomotives and returns through the rail(s) and earth to the TSS. In sections where booster transformers and return conductor are provided the current returns through booster transformer ; the traction rail(s) and partly through earth in the vicinity of TSS. Approximately midway between two adjacent TSS a dead zone known as ‘neutral section’ or ‘phase break’ is provided to separate the two sections of OHE fed by different phases. The power fed to the OHE on one side of the TSS is controlled by a feeder circuit breaker while the power fed to the OHE of each track is controlled by an interrupter. In case of fault on the OHE, the feeder circuit breaker trips to isolate the faulty OHE. A schematic diagram No. ETI/PSI/702-1 showing the general arrangement at a TSS is at APPENDIX – I

3.2 Nature of faults on the OHE

3.2.1 OHE is prone to frequent earth faults caused by failure of insulation or by OHE

snapping and touching the rail/earth or by a piece of wire dropped by birds which connects the OHE to earth at over line structures/supports or by miscreant activities.

3.2.2 The two sections of OHE fed by different phases are sometimes inadvertently

bridged causing wrong phase coupling. 3.3 Protection Scheme 3.3.1 The faults in the OHE are isolated by the feeder circuit breakers which operates

through either one or more of the following relays ; Distance mho relay (i) Instantaneous over-current relay (ii) Wrong phase coupling relay and (iii) High speed inter tripping relay

3.3.2 The faults in the traction transformer are isolated by one of the following relays :

(i) Differential relay (ii) IDMT over current relays for the primary (HV) as well as for the secondary

(LV) side. (iii) Instantaneous earth leakage relays on the primary (HV) side as well as on

the secondary (LV) side, (iv) Auxiliary relays for transformer faults i.e. Buchholz, excessive winding and

oil temperature trip and alarm and low oil level alarm.

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3.3.3 The faults in the shunt capacitor bank are isolated by one of the following relays :

(i) Over current relay (ii) Over voltage relay (iii) Under voltage relay (iv) Neutral current relay

3.3.4 In the event of the 25 kV feeder as well as transformer circuit

breakers failings to operate under fault conditions, the circuit breakers on the primary side of the transformer operates to isolate the fault.

3.4 Short circuit level 3.4.1 The fault level for different grid supply voltages based on a three phase

symmetrical short circuit fault is between 1000 MVA and 10,000 MVA depending upon the proximity of the traction sub-station to the generating station. The fault level for various system voltage in the vicinity of traction sub-station is as under :

Item

NOMINAL SYSTEM VOLTAGE ( k V )

22 25 66 100/110 132 220

Fault MVA

1000 550 3500 6000 10,000 20,000

3.5 Nature of load on the 25 kV system 3.5.1 The traction load is of frequent and rapidly varying nature and fluctuates between

no load and overloads. The load cycle varies from day due to non-uniform pattern of traffic.

3.5.2 An ac electric locomotive is fitted with single phase bridge connected silicon

rectifier with smothering reactor for conversion of ac to dc for feeding the dc traction motors. The ripple content is in region of 25 to 40%which introduces harmonics in the 25 kV power supply. The typical percentages of harmonics present in the traction current are as follows :

Width diode With With Rectifier Thyristor GTO’s 3rd harmonic (150 Hz) 15% 23% 3% 5th harmonic (250 Hz) 6% 14% 2% 7th harmonic (350 Hz) 4% 10% 0.5% 9th harmonics (450 Hz) - 4% 0.35% 11th harmonic (550 Hz) - 3% 0.40% Total harmonic distortion 16.64% 29.15% 3.68%

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3.5.3 The average power factor of electric locomotive and multiple unit train generally

varies between 0.7 and 0.8 lagging without compensation. 3.5.4 In big yards and loco sheds, large number of locomotives / Electrical multiple units

(EMUs) stand idle with only the load of their auxiliaries drawing higher reactive power. Therefore these are drawing power at low power factor.

3.5.5 For improving power factor, fixed shunt capacitor bank with 13% series reactor are

also installed at some traction sub-stations, the net kVAR rating of which is generally in the range of 2000 – 3500 kVAR

3.6 Electrical parameters

3.6.1 OHE is made up of a stranded cadmium copper catenary of 65 mm2 cross section or a stranded aluminum alloy catenary of 116 mm2 cross section and a grooved copper contact wire of 107 mm2 cross section, making up a total of 150 mm2 copper equivalent. For 2 x 25 kV AT feeding system, as a feeder wire, a stranded aluminum alloy catenary of 240 mm2 is used. The calculated OHE impedance value of AT feeding circuit (OHE : Al 116 or Cu 107 mm2 & feeder wire : Al, 240 mm2 ) for single track line is 0.0601 + J 0.1419 Ohm/Km ( at 25 kV system impedance). The OHE impedance values for conventional 25kV system are generally taken as under : (i) Single track OHE without BT & return conductor 0.41 70º Ohm/km

(ii) Double track OHE without BT & return conductor 0.24 70º Ohm/km

(iii) Single track OHE with BT & return conductor 0.70 70º Ohm/km

(iv) Double track OHE with BT & return conductor 0.43 70º Ohm/km

(v) Add booster transformer impedance @ 0.15 Ohms per booster transformer where these are provided.

(vi) Percentage impedance of traction transformer (12+/ -0.5 ) for 21.6 MVA at 27 kV.

3.7 Duties of the Circuit breaker 3.7.1 The circuit breaker is used at the following locations in the 25 kV ac, 50 Hz single

phase traction system.

(i) As transformer circuit breaker on the primary side of traction transformer for voltage of 22kV, 66 kV, 100 kV, 110 kV, 132 kV and 220 kV and also for incoming and outgoing transmission line at substation.

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(ii) As transformer circuit breaker on the secondary side of the traction transformer for voltage of 25 kV.

(iii) As feeder circuit breaker for controlling power supply to OHE through

interrupters for voltage of 25 kV.

(iv) As Shunt Capacitor Bank circuit breaker for controlling power supply to shunt capacitor bank for foliage of 25 kV.

(v) For controlling power supply to major yard/loco sheds for voltage of 25

kV 3.7.2 Special Duty to be performed by 25 kV CB 3.7.2.1 The 25 kV circuit breaker shall be called upon to trip under short-circuit

conditions. On an average, the number of fault trippings seen by the feeder circuit breaker per month are about 40 nos. but in exceptional cases the number of fault trippings per month may go as high as 120 numbers. The magnitude of short current interrupted generally ranges from 2 kA to 8 kA. The circuit breaker shall also be called upon to clear wrong phase coupling on the OHE when two sections of the OHE fed by different phases from adjacent sub-stations are accidentally shorted.

3.7.2.2 The design and construction of the 25 kV circuit breaker shall be such that it

is capable of a cumulative duty (n I2 where ‘n’ is the number of C-O operations at a current of I kA rms ) of 20,000 kA2 in service without adjustment /change of any part/contacts or SF6 gas/vacuum bottle lubrications and tightening of moving parts in the operating mechanism and cleaning of porcelain insulators can however be done as per manufacturer recommendations

3.7.2.3 The manufacturer shall supply graphs in support of suitability of offered

circuit breaker to perform above duties at the tender stage, indicating the cumulative duty which can be performed by offered CB without any maintenance /replacement of an components.

3.7.2.4 The 25 kV circuit breaker is also required to interrupt line charging and

magnetizing current of locomotive transformers without restrike. Values line charging current is of the order of 10A and values of magnetizing current for locomotive / EMU are likely to be as under :

(a) Locomotive - 6.38 A. (b) EMU - 6.0 A

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3.7.2.5 The 25 kV circuit breakers are normally operated through remote control. A

single shot auto reclosing scheme provided the remote control system to facilitate the reclosing of the circuit breakers automatically once within the preset “dead time” after the tripping of the circuit breaker on an OHE fault. This failure helps in quick restoration of power supply to the OHE if the fault is of a transient nature. The “dead time” is the period taken by the auto reclose mechanism to close the circuit breaker after the same has tripped on fault is set at 0.5 sec.

4.0 Environmental Conditions 4.1 The CB shall be suitable for outdoor use in moist tropical climate and in

areas subject to heavy rainfall, pollution due to industry and saline atmosphere and severe lightning. The limiting weather conditions for which the equipment has to withstand in service are indicated below :

(i) Maximum ambient air temperature 50ºC

(ii) Minimum ambient air temperature 0ºC

(iii) Average ambient air temperature over a period of 24 h 40ºC

(iv) Maximum relative humidity 100ºC

(v) Annual rainfall Ranging between 1750 mm & 6250 mm (vi) Number of thunderstorm days per annum 85 (Max)

(vii) Number of dust storm days per annum 35 (Max)

(viii) Number of rainy days per annum 120 (Max)

(ix) Maximum basic wind pressure 200 kgf/m2

(x) Altitude Not exceeding 1000 m

(xi) Pollution level Heavily polluted 4.2 The CB would be subjected to vibrations on account of trains running on

nearby railway tracks. The amplitude of these vibrations which occur with rapidly varying time periods in the range of 15 ms to 70 ms lies in the range of 30 to 150 micron at present, with the instantaneous peak going upto 350 micron.

5.0 Technical Specification

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5.1 The rating and other particulars The circuit breakers shall be designed for the following rating and other particulars : S.

No. Particulars RATED SYSTEM VOLTAGE (kV)

22 25 66 100/110 132 220 1 2 3 4 5 6 7 8

(i) Number of poles

2 1 or 2 ---------- 2 or 3 as required---------------

(ii) Nominal system voltage (kV)

22 25kV subject to variation from 19 kV to 27.5 kV occasionally touching 30 kV.

66 100/110 132 220

(iii) Rated voltage (kV)

24 52 72.5 110/123 145 245

(iv) Rated insulation level (a) Rated 1 minute wet power frequency withstand voltage

50 kv (rms)

95 kv (rms)

160 kv ( rms)

230 kv (rms)

275 kv

(rms)

460 kv (rms)

460 kV (rms)

(b) Rated impulse (1.2/50µs) withstand voltage

125 kV (peak)

250 kV (peak)

350 kV (peak)

550 kV (peak)

650 kV (peak)

1050 kV (peak)

(v) Rated frequency

-------------------------- 50 Hz ± 3% ------------------------

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(vi) Rated normal current

2000 A 1600 A 1250A 1250 A 1250 A 1250 A

(vii) Rated short circuit breaking current

40 kA

20 kA

31.5 kA

31.5 kA

31.5 kA

31.5 kA

(viii) Rated breaking capacity (symmetrical) (i) Single pole (ii) Two pole (iii) Three pole

-

1000 MVA

-

550 MVA

550 MVA -

-

2283.75 MVA

3955.5 MVA

-

3874.5 MVA

6710.8 MVA

-

4567.5 MVA

7911.1 MVA

-

7717.5 MVA

13367.1 MVA

(ix) Out of phase

breaking current

10 kA

(rms)

5 kA

(rms)

7.9 kA (rms)

7.9 kA (rms)

7.9 kA

(rms)

7.9 kA

(rms)

(x) Rated single capacitor bank breaking current

150 A 150 A 500 A 500 A 500 A 400 A

(xi) Rated line charging breaking current

10 A 10A 10A 31.5A 50A 125A

(xii) Rated small inductive breaking current

------------------------------------ 10 A -------------------------------

(xiii) Rated making current

100 kA (peak)

50 kA (peak)

-------------------- 78.8 kA (peak)-------

(xiv) Rated operating sequence

O-0.3s-CO-15s -CO

-----O – 0.3s – CO – 3 min - CO ----

(xv) Total break time

--------------------- Not more than 60 ms --------------------------

(xvi) Rated short time current

40 kA for 3s

20 kA for 3s

-------------- 31.5 kA for 1 s ------------

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(xvii) First pole to clear factor

---------- 1.5 for 2 parameters ------------- 1.3 for 4 parameters

(xviii) Corona extinction voltage

- - 53 kV 88 kV 106 kV 176 kV

(xix) Rating of auxiliary switch contacts (a) Rated voltage (b) Rated current (continuous) (c) Rated breaking current

--------------------------- 110 V dc --------------------------------- --------------------------- 10 A ------------------------------------- -------- 2A at 220 V dc with 20 ms circuit time constant ------

5.2 Clearances The design of the CB shall be such that when it is erected on the supporting structure, the following clearances / distance of lowest live part of the circuit breaker from the ground level / earth are achieved :

S.No

Clearance/ distance 22 kV 25 kV 66 kV 100 /110 kV

132 kV

220 kV

1 2 3 4 5 6 7 8 1. Minimum height of

lowest live part of the CB from ground level

3800 mm

3800 mm

4600 mm

4600 mm

4600 mm

5500 mm

2. From a point where a man may be required to stand for operation or for attending the breaker (sectional clearance)

3000 mm

3000 mm

3500 mm

3500 mm

4000 mm

5000 mm

3. Minimum height of the bottom most part of any insulator from the ground level.

----------------------- 2500 mm ------------------

4. Minimum clearance between live part & earth part.

500 mm

500 mm

630 mm

900 mm

1300 mm

2100 mm

5. Distance between pole centers for 2/3 poles

1500 mm

1500 mm

2000 mm

3000 mm

3000 mm

4000 mm

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6.0 Type and General Construction

6.1 The CB shall be of outdoor type suitable for mounting on steel structure. The 25 kV CB shall be of a single pole or double pole identical to single pole unit operated through a common shaft by operating mechanism, where as the CB of 22kV & higher voltage class covered by this specification shall consist of two or three (as required ) separate but identical single pole units operated through a common shaft by the operating mechanism. The CB shall comprise of -

(i) The pole (interrupting chamber and support insulators ) (ii) Operating mechanism cubicle and (iii) Mounting steel frame.

6.1.1 Interrupting chamber

6.1.1.1 SF6 Circuit Breaker

The operating mechanism, pole assembly and supporting structure shall be separate and capable of being packed and handled individually and erected in a given sequence. The interrupting chamber comprising fixed and moving contacts with an insulating enclosure shall be filled with SF6 gas and mounted on a supporting insulator. The design and construction of the CB shall be such that the SF6 gas leakage rate per year shall be limited to less than 1% by mass of the first filling. No condensation of SF6 gas shall take place on internal insulating surfaces. Inside the interrupting chamber there shall be an absorbent to absorb products of decomposition of SF6 gas and moisture if any. It shall be convenient to enable the pole being dismantled and removed from the operating mechanism with out SF6 gas escaping. The material used in the construction of the interrupting chamber shall be fully compatible with SF6 gas. The position of vents, diaphragms and pressure relief devices, if used, shall be so arranged as to minimize danger to the operator in the vicinity of the CB in the event of SF6 gas escaping under pressure. SF6 gas used in the CB shall conform to IEC-376 (1971) or the latest. The gas for the first filling shall be supplied with the CB.

6.1.1.2 Vacuum Circuit Breaker

The operating mechanism, the pole assembly and supporting structure of vacuum CB shall be separate and capable of being packed and handled individually and erected in sequence. The pole shall comprise the interrupting chamber and the support insulator. The interrupting chamber shall consist of vacuum bottle contained in porcelain hollow insulator. The vacuum bottle shall comprise a vessel sealed for lifetime with insulating walls and metal ends containing the fixed and moving contacts. The movement of the Moving contact in the vacuum enclosure shall be guided means of metal bellows.Suitable metallic shields shall be guided by means of metal bellows. Suitable metallic shields shall be provided for

518

preventing heat and metal vapour from arcing zone affecting the insulating envelope. These shields will also control the electric field when contacts are open and voltage is appearing across the CB contacts. This will mask high internal stress points and produce an almost linear axial grading of the external insulating surfaces. A shield shall also be provided to protect the bellows. The design and construction of vacuum bottle of the CB shall be such that the current chopping level is kept to the minimum and shall not produce any appreciable switching over voltages.

6.1.2 Porcelain hollow insulator and terminal connector

6.1.2.1 Porcelain hollow insulator

The porcelain hollow insulators used as the support insulator and interrupting chamber insulator for the CB shall be of out door type conforming to IS:5621 (1980) The porcelain hollow insulator shall be of single piece construction i.e. there shall be no joint within the porcelain. To reduce joints for leakage of SF6 gas (in case of SF6

gas CB), more than one porcelain hollow insulator shall be used for interrupting chamber insulator or support insulator. The shed profile shall have a lip at the extremity but free from ribs on the underside so as to avoid accumulation of dust and pollutants and permit easy cleaning. These insulators shall be procured from RDSO’s approved sources only.

The porcelain insulators for the support and interrupting chamber shall have minimum creepage distance as given in the table below :

Rated voltage (kV) 22 25 66 100/110 132 220 Minimum creepage distance (mm) i) Support insulator ii) Interrupting chamber insulator

600 600

1300 1300

1813 1450

3075 2460

3625 2900

6125 4900

6.1.2.2 Terminal Connectors

6.1.2.2.1 The CB shall have aluminium terminal pads and shall be supplied with the flexible terminal connectors as per RDSO Drawing No. ETI/PSI/11060 (Appendix – II), suitable for connection to 50 mm outside diameter aluminium tubular bus bars for 22kV & 25 kV CB and for 66kV, 100/110 kV, 132 kV and 220 kV CB the terminal connector shall be as per RDSO drawing No. ETI/PSI/11030 (mod G) (Appendix – III), suitable for connecting to “ZEBRA” 28.62 mm ACSR conductors. The connectors shall be procured only from manufacturers approved by DG/TI/RDSO/Lucknow.

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6.1.2.2.2 The connectors shall conform to IS :5561 (1978 ) and design shall be such,

so as to be connected to the equipment terminal pads with minimum four 12mm diameter bolts, nuts, lock-nuts of stainless steel conforming to IS:1570 (PtV) (1978) grade 04Cr, 17Ni and Mo2 each of these bolts shall have two flat washers.

6.1.3 Contacts for both Vacuum & SF6 CB

6.1.3.1 Main contacts The main, fixed and moving contacts of the CB shall have ample cross-

section and contact pressure for carrying the rated current and short time current without excessive temperature rise, pitting and welding.

Arcing tips shall be made up of cupro-tungsten alloy or any other suitable material. The nozzle, main contacts & arcing contacts or parts thereof which are liable to wear shall be replaceable (in case of SF6 gas CB) Indication for contact wear condition shall be provided.

6.1.3.2 Auxiliary Switch Contacts

Apart from the auxiliary switch contacts required exclusively by the manufacturer for the functioning of the CB at least 6 pairs of normally open (NO) contacts and 6 pairs of normally closed (NC) contacts shall be provided additionally for the exclusive use of the Purchaser. The auxiliary contacts which are operated in conjunction with the main contacts shall be positively driven in both the directions.

6.1.4 Operating Mechanism

6.1.4.1 The CB shall be operated by a motor charged spring stored energy

mechanism. Both opening and closing operations shall be done by the stored energy of spring(s). The motor shall be so rated that the time required for fully charging the closing spring is not more than 15 seconds. The closing action of the CB shall charge the opening spring so that the CB is ready for opening anytime thereafter. The spring shall be of robust design using tested steel as per IS : 7906 or IS : 7907 (1976). The ends of the compression springs if used shall be flattened to enable proper fixing and shall be flattened to enable proper fixing and shall minimize the possibility misalignment.

6.1.4.2 The motor for spring charging shall be suitable for operation from a 110V

dc power from a battery. The voltage at motor terminals is likely to vary between 110% and 85% of the normal value. The carbon brushes provided shall have cooper pigtails for carrying motor current. A miniature circuit breaker of adequate ratings and of reputed make shall be provided in the

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motor circuit for protection of the motor against over current and earth faults.

6.1.4.3 The operating mechanism shall be designed so that the CB can be operated

from the operating mechanism cubicle itself as well as remotely from the control panel in the TSS and also from the Remote Control Centre (RCC) which is situated away from the CB. For this purpose “LOCAL / REMOTE” two way selector switch shall be provided in the operating mechanism cubicle. When the switch is in the “LOCAL” position, the CB can be operated locally and when it is in the “REMOTE” position, the CB can be operated from the control panel or from the RCC. The selector switch shall be spring loaded in order that it automatically returns to the

“REMOTE” position. For closing and opening the CB from the operating mechanism cubicle itself, the switch shall be of push button type or knob type.

6.1.4.4 The operating mechanism shall also be provided with a suitable emergency device to manually open the CB in the event of failure of any part of dc control circuit including the opening coil in the operating mechanism.

6.1.4.5 The operating mechanism shall also be provided with a suitable device to

manually close the CB (mainly for maintenance purposes ). In addition, a detachable handle/crank shall be provided for manually charging the closing spring. The height from ground/platform level at which the handle/crank is to be inserted in the operating mechanism shall be between 1500 mm and 2000 mm so as to enable its operation conveniently by the operator standing on the ground / platform. The height of other devices like interlock, ON-OFF switches, selector etc. to be operated from ground / platform shall also be at a height between 1500mm and 2000mm.

6.1.4.6 In addition to the manually operated local mechanical opening and closing

devices as indicated in Clause 6.1.4.4 & 6.1.4.5 above, provision shall also be made by means of a suitable crank or handle for slow closing slow opening of the circuit breaker for maintenance purposes.

6.1.4.7 The closing coil and the opening coil in the operating mechanism shall be

suitable for operation from 110V dc power supply from a battery. The closing coil shall be suitable for operating at a voltage variation of +10% to –15%, while the opening coil shall be suitable for operating at a voltage variation of +10% to –30%

6.1.4.8 The circuit breakers shall be fitted with an electrical anti-pumping device, to

give priority to tripping command in case of a persisting closing command being simultaneously present.

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6.1.4.9 The circuit breaker shall be trip-free.

6.1.4.10 Facility for trip circuit supervision shall be provided with indication to remote locations (RCC)

6.1.4.11 An operation counter having five digit recording mechanism for the number

of tripping operations shall be provided at a suitable location so as to be conveniently read by the operator standing on the ground. The operation counter shall be of lock type and shall not be of resetable type.

6.1.4.12 Mechanical indicators clearly visible from ground, shall be provided for

‘CLOSED’ and ‘OPEN’ conditions of the CB. 6.1.4.13 All working parts of the operating mechanism shall be of corrosion resisting

material bearings, if any, shall be sealed type. Bearing, pins, bolts nuts and other parts shall be adequately locked to prevent loosening.

6.1.4.14 In case of drop in pressure of SF6 gas below the set value the temperature

compensated alarm pressure switch shall get actuated for generating an alarm. If the drop in the pressure continues, the temperature compensated lock out pressure switch shall get actuated to cause the circuit breaker to trip and get locked in the tripped condition. Separate auxiliary contact from pressure switches shall be made available for tele-signalling the alarm condition from the alarm pressure switch and the trip and lock out condition from the lock out pressure switch. The maximum pressure, normal pressure, alarm actuating pressure and tripping & lock out pressure of the circuit breaker shall be furnished by the manufacturer on the schematic drawing of the CB. Maximum and minimum permissible pressure of SF6 shall be indicated on the rating plate also.

6.1.4.15 The operation of closing device when CB is already in “CLOSED”

condition shall not cause damage to any part of the CB or endanger the operator standing near the CB. The power requirement for tripping coil or closing coil shall not exceed 200W and power requirement at any time including spring charging shall not exceed 1000W.

6.1.4.16 In the event of 110V battery supply voltage dropping below 77V which is

minimum voltage prescribed for operation of tripping coil to trip the circuit breaker, the circuit breaker should trip automatically by means of a suitable arrangement / device (CTD).

6.1.4.17 Shock absorbers used (if any) shall not require any maintenance during the

entire life of the CB. 6.1.4.18 The operating mechanism and associated accessories shall be enclosed in a

weather, dust and vermin proof cabinet or cubicle. The cubicle made of at

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least 2mm thick sheet steel (of tested quality) with provision for padlocking. The cubicle shall be tested for dust and water proofing as per IP 55 as per IS:2147 (1962) from any national laboratory.

6.1.4.19 Suitable heater(s) shall be provided in operating mechanism cubicle to

operate at 240V ac, 50 Hz single phase supply to prevent condensation of moisture during monsoon/winter. A 240V ac. 5A, 3 pin socket outlet for an inspection lamp shall also be provided. Miniature circuit breaker of reputed make & of

adequate rating shall be used for protection of the heater circuit for overload and earth fault.

6.1.4.20 The entry of all cables into operating mechanism cubicle shall be only

through suitable cable glands which shall not allow ingress of vermin, insects etc. into cubicle. The cable glands shall be supplied with the CB. Five cable glands shall be provided of which three shall be for cable of 16.5 mm outside diameter while the balance two glands shall be for cable of 14 mm outside diameter.

6.1.4.21 The wiring inside the operating mechanism cubicle shall be with 1100V

grade PVC insulated single core cable conforming to IS:1554 (Pt. I-1988), with stranded copper conductors of adequate cross-section (with min 2.5 Sq strand copper) so proportioned as to reduce voltage drop and I2 R losses to the minimum. The ends of wires shall be terminated with crimped eye type lugs. The wiring for 110V dc control circuit and 240V ac circuit shall be segregated and properly identified. The positive and negative wires of dc circuits shall also be segregated. The length of the cables used shall be kept to the minimum. Wire inside the cubicle shall be properly laid on trays and anchored to avoid breakage during vibration.

6.1.4.22 The terminal end of all wires shall be provided with numbered interlock

type ferrules which shall be of PVC or other durable material with markings (numbers) either engraved or punched so as to be indelible. The ferrules shall be of white colour with lettering thereon in black. All wiring shall be properly supported and suitably protected to avoid rubbing against any metallic part.

6.1.4.23 Terminal blocks of standard make shall be provided in the operating

mechanism cubicle. There shall be insulating barriers between adjacent terminals. The terminals shall be of stud type with spring washers. Suitable dust proof shrouds of unbreakable transparent material shall be provided on each terminal block. The terminal blocks used for dc and ac circuits shall be clearly distinguished and separated from each other. Similarly positive and negative terminations of the wiring of the dc circuit shall be segregated and separated by insulting barriers.

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6.1.4.24 The following gauges/switches shall be provided for monitoring the

pressure / density of SF6 gas ( in case of SF6 CB). The pressure gauge shall have no oil to avoid leakage. The gauges shall be so positioned as to clearly and conveniently readable from ground/platform (1500mm to 2000mm from ground/platform). The density pressure switch(es) monitor and pressure gauges shall be common for all the poles of the breaker and these shall indicate and actuate for any loss of pressure in the CB. (i) An accurate pressure gauge of adequate range. (ii) Gas density temperature compensated pressure switch(es).

6.1.4.25 For earthing of the operating mechanism cubicle, two earthing

terminals of adequate capacity to carry the rated short circuit current shall be provided. The earthing terminal shall be provided with 17.5 + 0.5/ - 0.0 mm diameter stud/hole for fixing the earthing flat.

7.0 Steel supporting frame

7.1 The steel supporting frame for CB shall be designed with a factor of safety of not less than 2.5 with respect to the yield point under conditions of maximum loading for a basic wind pressure of 200 kg/m2 on 1.5 times the projected area of each member of one face and taking into account the dead and impact loads of CB. Only tested quality steel shall be used confirming to IS : 808 (1989) and test certificate shall be furnished to RDSO. The fixing distance for steel supporting frame on the foundation to RDSO. The fixing distance for steel supporting frame on the foundation for single pole 25kV CB shall be 650x725 mm

7.2 Typical design calculations for the steel supporting frame shall be

furnished by the manufacturer to the RDSO during design approval stage for checking the safety of the supporting frame proposed to be used.

7.3 For earthing at least 2 legs of the steel supporting frame shall be

provided with stud/hole type earthing terminals of adequate capacity to carry the rated short circuit current safely. The earthing shall be provided with 50 x 8 mm MS flat. The terminal shall be provided with 17.5 + 0.5 / -0.0 mm diameter stud/hole for fixing the earthing flat.

8.0 Foundations

Gravity foundation of plan mass concrete to M 10 mix as per IS: 456 (1978) shall be designed considering the normal and impact loading in opening / closing operations. The basic wind pressure shall be taken as 200 kgf/m2 . Two alternative design of foundations one for a normal soil of

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bearing capacity 5500 kgf/m2 and other for black-cotton soil of bearing capacity 16500 kgf/m2 shall be furnished by the manufacturer. The foundation block design shall give complete details of its size of pockets provided for grouting the fixing bolts. Detailed design calculation for proposed foundation shall be submitted to DG (TI) RDSO for scrutiny and approval.

9.0 Corrosion prevention system

9.1 Galvanising The operating mechanism cubicle and steel supporting frame shall be hot

dip galvanized in accordance with RDSO Specification No. ETI/OHE13/(4/84) and the weight of zinc coating shall be not less than 1000 gm/m2.

9.2 Painting If the successful tenderer / manufacturer is not able to hot dip galvanize the

operating mechanism cubicle and these steel supporting frame as per Clause 9.1, it shall be painted conforming to RDSO’s specification No. M&C/PCN-102/86 AND M&C/PCN-110/88

10.0 Fasteners

All fasteners of 12 mm diameter and less exposed to atmosphere shall be of stainless steel and those above 12mm diameter shall be of preferably stainless steel or of mild steel hot dip galvanized, to RDSO’s specification No. ETI/OHE/18(4/84).

11.0 Interlocking arrangements 11.1 The CB shall be provided with a suitable interlocking device for electrical

and mechanical interlocking with its associated isolator(s), such that (i) the isolator(s) can be operated only when the CB is locked in ‘open’ condition and (ii) the CB can not be operated both manually and electrically either on LOCAL or on REMOTE unless the isolator(s) is locked in the CLOSE or OPEN condition.

11.2 Interlocking Scheme for 25 kV CB

11.2.1 Three types of isolator interlocking schemes shall be utilized. The details of these schemes are indicated below.

(a) Single isolator interlocking (SI)

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Under this scheme, the circuit breaker shall be interlocked with its single associated isolator. This interlocking scheme shall be provided on the circuit breaker to be installed as transformer breakers and circuit breaker for controlling feed to the shunt capacitor.

In this scheme the key shall be trapped in the lock mounted on the circuit breaker mechanism when the circuit breaker is in closed position. The key can be released from the operating mechanism when the circuit breaker is in the ‘open’ position only. Any attempt to forcibly withdraw the key when the circuit breaker is in the closed position shall result in tripping of the circuit breaker. The key thus released from circuit breaker shall be utilized to operate the lock mounted on the isolator. It shall be possible to release this key from the isolator lock only when the isolator is locked in ‘open’ or ‘closed’ position. Once the key has been removed from the circuit breaker operating mechanism, it shall not be possible to operate the circuit breaker either manually or electrically by local / remote control.

(b) Double isolator interlocking (DI)

The scheme is identical to the SI scheme but in this the circuit breaker shall be interlocked with its two numbers associated isolators. The interlocking shall be provided on circuit breaker to be installed as feeder breakers.

(c) Bus coupler isolator interlocking (BCI)

Under this scheme the circuit breakers of adjacent bay shall be interlocked with the bus coupler isolator / interrupter. The operation of the bus coupler isolator/interrupter shall not be possible unless both the circuit breakers of adjacent circuit are locked in open position. In this scheme the two keys so released from the circuit breakers shall be inserted in a key exchange box (which shall be supplied loose) for releasing a third key which shall be used for operating the bus coupler isolator /interrupter. The details of all these schemes indicated above are given in drawing no.ETI/PSI/SK/5214 enclosed as Appendix (IV)

11.2.2 SI interlocking scheme shall include supply of 2 locks alongwith the common interlocking key, out of which one lock shall be duly mounted on the circuit breaker operating mechanism and the other shall be supplied loose for mounting by Purchaser on the associated isolator.

11.2.3 DI interlocking scheme shall include supply of 3 locks along with the common

interlocking key, out of which one lock shall be duly mounted on the circuit breaker operating mechanism and 2 locks shall be supplied loose for mounting by Purchaser on the associated isolators.

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11.2.4 BCI interlocking scheme shall include supply of a key exchange box which can be operated by the two keys released from the circuit breakers of adjacent circuits and one loose lock operated by the key released from the key exchange box. The loose lock shall be suitable for directly mounting on the bus coupler isolator (supply of locks fitted on the circuit breakers operating mechanism shall be covered under SI/DI interlocking schemes.

11.2.5 The interlocks provided on the circuit breakers installed at a traction sub-station

shall have non-interchangeable key codes to safeguard against any mal-operation.

11.2.6 The lock meant for mounting on the associated isolator(s) and bus coupler

isolator shall be bolt type lock of approved design. The internal mechanism of the lock shall be made of non-ferrous metal and the outer housing shall be of steel hot dip galvanized. RDSO drawing No. ETI/PSI/SK/344 showing the interlocks is attached with this specification as Appendix VI. The key when trapped inside the lock shall remain properly secured so as to safeguard against its working loose due to vibrations.

11.2.7 One spare duplicate key shall be supplied with each of the three types of

interlocking schemes. 11.2.8 In order to facilitate the ordering of interlocks, the tenderer shall separately

furnish prices for SI, DI and BCI interlocking schemes. The requirements of interlocks and the key codes to be adopted shall be ascertained by the successful tenderer from the respective consignee.

11.3 Interlocking scheme for 22 kV, 66 kV, 110kV, 132 kV and 220 kV CB 11.3.1 Two types of interlocking arrangement designated as type-I and Type-II may be

used. In Type-I, the circuit breaker is interlocked only with its associated double pole or triple pole isolator. In Type-II CB is interlocked with associated line isolator and bus coupler isolator. The operation of the line isolators and bus-coupler isolator should not be possible unless both the circuit breakers of the two adjacent circuit are locked in the open condition.

11.3.2 Type_I inter locking scheme shall include supply of two locks and a common

key, out of these two locks, one lock shall be mounted by the manufacturer on the circuit breaker operating mechanism and the other supplied loose for mounting by the purchaser on the associated isolator. The design of the lock shall be approved by RDSO.

11.3.3 Type-II interlocking scheme shall include supply of 3 Nos. loose locks for

mounting on associated isolators by the purchaser. These locks shall be operated through the common key being supplied under Type-I inter locking

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scheme. Details of interlocking scheme indicated above are given in Drawing No.ETI/PSI/5212 (MOD B) at Annexure (V).

11.3.4 When both Type I and II inter locking schemes are ordered for a circuit

breaker, in all 5 Nos. locks and a common key shall be supplied with each circuit breaker. Out of these 5 locks, one lock along with the key shall be mounted on the operating mechanism of the circuit breaker by the manufacturer of the circuit breaker and other 4 blocks shall be supplied loose for mounting on associated isolator(s), line isolators and bus coupler isolator by the purchasers.

11.3.5 Requirement of inter locks under Type-I and Type-II interlocking scheme at

a Traction substation having double circuit incoming line and provided with two nos. Traction transformers shall be as follows :

Type - I Scheme - 2 sets. Type - II Scheme - 2 sets. 11.3.6 The inter locks provided on the circuit breaker installed at a particular

traction substation shall have non-interchangeable key codes to safeguard against any mal-operation.

11.3.7 The lock for mounting on the isolators shall be a castle type lock of

approved design. However, the lock for mounting on the circuit breaker may be a bolt type lock, with adopter. The internal mechanism of the lock shall be of non-ferrous material and the outer housing shall preferably be of mild steel hot dip galvanized. The key, when trapped inside the lock, shall remain properly secured and it shall not become loose due to vibration.

11.3.8 One spare (duplicate) key shall be supplied for each type of the interlocking

arrangements. 11.3.9 In order to facilitate the ordering of interlocks, the tenderer shall separately

furnish prices for Type-I and Type-II interlocking arrangements. The scope of supply for inter locks shall include locks (and keys) to be fitted on the circuit breaker(s) and also on the associated isolator(s). The requirements of interlocking and the key codes to be

adopted shall be ascertained by the successful tenderer from the consignee. 11.3.10 The electrical and mechanical interlocks shall be procured only from

RDSO’s approved manufacturers. Approved supplier for electrical and mechanical interlocks are : (i) M/s. Enterprising Engineers, Bhopal. (ii) M/s. PS Power Controls, Chennai.

12.0 Parts, fittings and accessories

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12.1 The following parts, fittings and accessories shall be provided for each CB :

(i) SF6 gas pressure gauge (in case of SF6 CB) (ii) Temperature compensated gas density pressure switch(es) (in case of

SF6 CB)

(iii) Provision for replenishment of SF6 gas, preferably in the operating mechanism cubicle (in case of SF6 CB)

(iv) Contact wear indication.

(v) Operating mechanism cubicle door padlocking arrangement with

padlock.

(vi) Local operated mechanical opening and closing device.

(vii) Spring loaded local/remote selector switch.

(viii) Local operated electrical closing and opening device (push or knob)

(ix) Operation counter.

(x) Interlocking device (as required)

(xi) Terminal connectors.

(xii) Earthing terminals.

(xiii) Name / rating plate.

(xiv) Mechanical ‘ON’ and ‘OFF’ position indicators.

(xv) Handle / crank for slow closing and slow opening of CB.

(xvi) Supporting frame work.

(xvii) Lock out device.

(xviii) Tripping device in case of 110V dc failure (CTD).

(xix) Anti-pumping device.

(xx) Foundation Bolts.

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(xxi) Handle/crank for charging the closing spring manually. 12.2 The name / rating plate shall contain the following particulars

Each CB shall be provided with a rating plates (both Hindi & English weather proof material, fitted in a visible position showing the items indicated below. The letters/numbers on the plate shall be indelibly marked by etching/engraving.

(i) Manufacturer’s name and country of origin. (ii) Type designation and No. of pole.

(iii) Serial number.

(iv) Rated voltage.

(v) Rated normal current.

(vi) Rated frequency.

(vii) Rated short circuit breaking current.

(viii) Rated short circuit peak making current.

(ix) Rated single capacitor bank breaking current.

(x) Rated out of phase breaking current.

(xi) Rated short time withstand current and it’s duration.

(xii) Rated insulation level.

(xiii) Rated operating sequence.

(xiv) Control circuit voltage with permissible variation for

(a) Closing coil (b) Opening coil (c) Motor voltage

(xv) Total weight of CB (xvi) Specification conforming to IEC / RDSO

(xvii) Quantity of SF6 gas ( by mass )

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(xviii) SF6 Gas pressure (a) Maximum (b) Normal (c) Alarm (d) Lock out

(xix) Vacuum level in Torr (for vacuum CB) (xx) Order reference

(xxi) Month / Year of manufacture

13.0 Testing 13.1 General 13.1.1 After all the designs and drawings have been approved and clearance given to this

effect by RDSO, the manufacturer shall take up manufacture of the prototype for inspection / testing by RDSO. It is to be clearly understood that any changes to be done on the prototype as required by RDSO, the same shall be done expeditiously.

13.1.2 Prior to giving a call to the Purchaser / Director General Traction Installations,

Research Designs and Standards Organisation, Lucknow ( DG/TI/RDSO, Lucknow) for inspection and testing of the prototype, the successful tenderer /manufacturer shall submit a detailed test schedule consisting of test procedures, schematic circuit diagrams, items / parameters to be checked and values required as per specification for each of the tests and the number of days required to complete all the tests at one stretch. The schedule shall also indicate the venue of each of the tests. Once the schedule is approved, the tests shall invariably be done accordingly. However, during the process of type testing or even later, the Purchaser / DG/TI/RDSO, Lucknow reserves the right to conduct any additional test(s), besides those specified herein, on any equipment / item so as to test the equipment / item to his satisfaction or for gaining additional information and knowledge. In case any dispute or disagreement arises between the successful tenderer / manufacturer and the representative of the purchaser/DG/TI/RDSO, Lucknow during the process of testing as regards the procedure for type tests and/or the interpretation and acceptability of the results of type tests, it shall be brought to the notice of the Purchaser/DG/TI/RDSO, Lucknow as the case may be whose decision shall be final and binding. Only after the prototype of the equipment is manufactured and ready in all respects, shall the successful tenderer / manufacturer give the actual call for the inspection and testing with at least 15 days notice for the purpose.

13.1.3 In the event of the tests not being carried through to completion at one stretch for

any reason attributable to the successful tenderer / manufacturer and it is required

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for the representative of the Purchaser/DG/TI/RDSO, Lucknow to go again or more number of times to the works of the successful tenderer/manufacturer or to any reputed testing house/laboratory where tests are being done for continuing and/or completing the tests on the prototype(s) of the equipment, the successful tenderer / manufacturer shall reimburse to the Purchaser/DG/TI/RDSO, the cost for the representative(s) having to visit the works or other place(s) for the tests more than once. The cost as claimed by the Purchaser/DG/TI/RDSO Lucknow shall be paid through a Demand Draft to the concerned Accounts Officer of the Purchaser/DG/TI/RDSO Lucknow as shall be advised to the successful tenderer / manufacturer.

13.1.4 The tests shall be conducted on the prototype of the CB at the works of the

successful tenderer / manufacturer or at an reputed testing house or laboratory in the presence of Purchaser/DG(TI)/RDSO, Lucknow or his authorized representative. The prototype shall be complete in all respects, including the terminal connectors as would be supplied if it had passed the tests. The tests shall be conducted as per relevant Governing Specification and as modified or amplified herein. In case of test being conducted at Government test house, the presence of Purchaser’s representative for witnessing the tests may be waived off subject to the discretion of Purchaser/DG(TI)/RDSO, Lucknow.

13.1.5 For the tests which are conducted in the laboratories of Central Power Research

Institute, Bhopal/Bangalore, Electrical Research Development Association, Vadodra or any such testing house or laboratory a clear certificate to the effect that the equipment has passed the tests as per specification shall be obtained by the manufacturer and submitted to the Purchaser/DG (TI) RDSO, Lucknow. Full details of the tests and test parameters shall be furnished along with the test reports.

13.2 Type tests

The type tests comprises of :

(i) Mechanical operation tests as per clause 13.2.1 (ii) Temperature rise tests as per clause 13.2.2

(iii) Dielectric tests as per clause 13.2.3

(a) Rated lightning impulse voltage withstand test as per clause 13.2.3.1 (b) Rated one minute power frequency wet withstand voltage test

as per clause 13.2.3.2 (iv) Rated short circuit making and breaking capacity test (basic short

circuit test duties) as per clause 13.2.4 (v) Rated short time withstand current & peak withstand current test as

per clause 13.2.5

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(vi) Line charging breaking current test as per clause 13.2.6 (vii) Test to prove the rate transient recovery voltage (TRV) and rate of

rise of recovery voltage (RRRV) as per clause 13.2.7 (viii) Short line fault test (kilometers faults) as per clause 13.2.8

applicable only for 66 kV and above.

(ix) Out of phase making & breaking test as per clause 13.2.9

(x) Capacitor current switching test as per clause 13.2.10

(xi) Measurement of RIV level as per clause 13.2.11 – (Applicable for 110 kV & above CB).

(xii) Special electrical test – applicable for 25kV circuit breaker only as per clause 13.2.12

13.2.1 Mechanical operation test

13.2.1.1 The test shall be conducted in accordance with clause 6.101of IEC 60056(1987) but the number of operations shall be 10,000 in case of 22kV & 25 kV CB and 5000 in case of 66, 100/110, 132 and 220 kV instead of 2000 specified therein. For this purpose, CB shall be tested in accordance with Table XII of IEC 60056 (1987). However, the sequence shall be repeated 5 times to complete 10,000 operations in case of 22 kV & 25kV CB and 2.5 time in case of 66kV, 100/110 kV, 132 kV and 220 kV CB.

13.2.1.2 Following checks/ tests shall be done before commencement of mechanical

operation test.

(i) General visual inspection of the equipment to check its conformity with the approved drawings.

(ii) Operation of various circuits and devices of the CB.

(iii) Measurement of dimensions of components liable to wear, dimension of opening, closing and wipe springs, lift of tripping and closing coil plunger, and clearances of opening and closing coil armatures.

(iv) Measurement of insulation resistance of auxiliary and motor circuits with 500V meter.

(v) Measurement of contact resistance of main circuit by dc voltage drop.

(vi) Mechanical operation comprising 5 closing and 5 opening operations at the specified normal, minimum and maximum control voltages.

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(vii) Closing and opening travel characteristics of contacts to record the following at

the specified normal, minimum and maximum control voltages (at minimum & maximum SF6 gas pressure in case of SF6 CB.

Opening speed & time Closing making speed. Closing speed & time Contact bounce and Contact level

13.2.1.3 The measurements of items (v) & (vii) above shall be repeated after every 5000 operations for 22 kV & 25 kV CB and 2500 operation in case for 66, 100/110, 132 & 220 kV CB and observations made/results obtained shall be evaluated by comparing with the figures and the tolerances given by the successful tenderer / manufacturer in the SOGP.

13.2.1.4 After completion of 10,000 operations in case of 22kV & 25 kV CB and

5000 operation in case of 66kV, 100/110kV, 132 kV and 220 kV CB and before dismantling the CB for internal inspection, the following checks/tests shall be performed.

(i) Gas pressure at ambient temperature (in case of SF6 CB). The same

shall be within 99% of pressure recorded at the beginning of the operation.

(ii) Dielectric tests on control and auxiliary circuit (110V dc) by

applying 2 kV (rms) for 1 min. after disconnecting the motor. (iii) Spring charging motor shall be tested at 1 kV (rms) for 1 mm.

(iv) Power frequency dry withstand voltage test on complete CB for 1

minute.

(v) Temperature rise test on opening and closing coils as 13.2.2.2

(vi) Closing and opening travel characteristics of contacts to record the following at the specified normal, minimum and maximum control voltages (at minimum & maximum SF6 gas pressure in case of SF6

CB. Closing speed Opening speed. Closing making speed Contact bounce and Contact level

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The above parameters shall be within the specified limits declared by the manufacturer in SOGP.

(vii) For SF6 gas CB the tightness of gas sealing arrangement shall be

measured by tests conducted on either a complete CB or on sub-assemblies in combination with tightness co-ordination chart as provided in the Appendix ‘EE’ of IEC 60056(1987) to ascertain total system leakage rate and time between refilling of SF6 gas pressure. Drop in pressure shall not be used to detect the leakage rate of the SF6 gas as it will not indicate the correct readings.

13.2.2 Temperature rise test 13.2.2.1 On main contact

The temperature rise test on the main circuit ( contacts )and terminal connectors shall be carried out as per clause 6.3 IEC 694(1980). Contact resistance of the main circuit shall be determined by dc voltage drop recorded before and after this test.

13.2.2.1.1 Procedure

Unless otherwise specified, temperature rise on the main circuit be made on a new CB in closed position with clean contacts. The test shall be made with rated normal current.

The test shall be done in indoor environment substantially free from currents, except those generated by heat from the CB being tested. Temporary connections to the CB terminals shall be such that no significant amount of heat is conducted away from, or conveyed to the CB during the test. The temperature rise at the terminal of main circuit and the temperature connections at a distance of 1 m from the terminal shall be measured as a difference of temperature rise shall not exceed 5° C. The type and sizes of temporary connections shall be recorded in the test report.

13.2.2.1.2 The maximum temperature rise of contacts, terminals for connection to

external conductors by bolts, material used as insulation and metal parts contact with insulation shall not exceed the values given in Table below when carrying rated normal current continuously. These values shall be conforming to IEC 694 (1980).

TABLE

Sl. No.

Nature of faults / components Maximum temperature rise at an ambient temperature not exceeding 50° C

1. CONTACTS i) Bare copper and bare copper

25° C

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alloy in SF6 gas ii) Silver contacts in SF6 gas

55° C

2. Terminal for external connection by bolts.

40° C

3. Insulator (Porcelain). 130° C 13.2.2.1.3 In case a layer of coating of silver over the contact area is not maintained at

the end of any tests the contacts shall be regarded as bare for the purpose of temperature rise limits.

13.2.2.2 On Auxiliary equipment (Closing & opening coils)

The temperature rise test on the coils shall be carried out a per clause 6.3 of IEC 694 (1980).

13.2.2.2.1 Procedure

Temperature rise on auxiliary equipment (closing and opening coils) shall be made by the method of measuring variation of resistance before and after energisation at 110V dc. For this purpose the coil (s) shall be energized 10 times for 1s, the interval between the instant of each energizing being 2s. The resistance of the coil shall be measured immediately before and after such energisation. The value of temperature rise, over the ambient, shall be computed.

13.2.2.2.2 The maximum temperature rise shall be as per table V of IEC 694(1980)

considering the insulating material of the coil. The temperature rise shall not exceed the value a guaranteed by the manufacturer in SOGP.

13.2.3 Dielectric tests

Dielectric tests shall be carried out generally in accordance with Clause 6.1 of IEC 694(1980). Humidity and air density correction factor if less than 1.0 shall not be applied. The tests shall be done at a minimum SF6 gas pressure ( in case SF6 CB). The test shall comprises of :

13.2.3.1 Rated impulse withstand voltage test The CB shall withstand rated impulse voltage of 1.2/50 µs wave shape as

per table below :

NOMINAL SYSTEM VOLTAGE OF CB (kV) 22 25 66 100/110 132 220

APPLIED

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VOLTAGE (kVp)

125 250 350 550 650 1050

13.2.3.2 Rated one minute wet power frequency voltage withstand test The CB shall withstand rated one minute wet power frequency withstand

voltage as per table below.


APPLIED VOLTAGE (kV rms)

50

95

160

230

275

460

13.2.4 Basic short circuit test duties The basic short circuit test duties 1 to 5 shall be in accordance to clause

6.106 of IEC – 60056 (1987). The power frequency recovery voltage shall be as per clause 6.104.7 of IEC 60056 (1987).

13.2.5 Rated short time withstand current & peak current withstand test This test shall be conducted as per clause 6.5 of IEC 694(1980) and the

values shall be as under


Value of current & duration

40KArms for 3s

100kAp

20 KArms for 3s 50kAp

-------- 31.5 kArms for 1s, 78.75kAp---

-

13.2.6 Line charging current switching test

This test shall be conducted as per clause 6.111.5.1 of IEC 56 (1987) test values shall conform as given in SOGP.

13.2.7 Test to prove rated transient recovery voltage (TRV) The measurement shall be done as per clause 6.104.5 of IEC 60056(1987). 13.2.8 Short line fault test

This test shall be conducted as per clause 6.109 of IEC 60056(1987)

13.2.9 Out of Phase making and Breaking test

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This test shall be conducted as per clause 6.110 of IEC 60056 (1987) at its rated out of phase breaking current. The applied voltage and power frequency recovery voltage shall be set as per table below :


Current 10KA rms

5 KA rms

-------- 7.9 kA rms ----------

Recovery voltage

48 kVrms

60 kVrms

144 kV rms

246 kV rms

290 kV rms

490 kV rms

13.2.10 Capacitor bank breaking current test The test shall be carried out at its rated single capacitor bank breaking current

generally as per Clause 6.111 of IEC 60056 (1989). No restrike shall occur during the test. The breaking current shall conform to the guaranteed value.

13.2.11 Measurement of RIV level

The test shall be conducted as per Clause 6.2 of IEC 694 (1980). 13.2.12 Special electrical test (applicable for 25 kV CB only)

CB shall be subjected to short circuit making and breaking capacity test at a current of 6.25 kA for duty cycle of CO-15s-CO for 200 close-open operations. During this test no part of CB shall require any inspection / maintenance, change of SF6 gas or vacuum bottle or any other part. The standard value of prospective TRV shall be taken as 64kV. Other conditions shall be similar to short circuit test duties specified in IEC 56 (1987). Test may be interrupted once after every 10 CO operations if need arises to enable the components to cool down to ambient temperature.

13.3 Condition of CB during the tests conducted as per clause no. 13.2.4, 13.2.5,

13.2.6, 13.2.7, 13.2.8, 13.2.9, 13.2.10, 13.2.11 and 13.2.12 of this specification shall conform as under :

13.3.1 During these tests the CB shall neither show signs of excessive distress nor endanger the operator. No disruptive discharge between energized parts and earth, shall occur during the tests. There shall be no indication of significant leakage current to the earthed structure or screens whenever fitted during the test. The earthed parts shall be connected to earth through a fuse consisting of a copper wire of 0.1 mm diameter and 5 cm length. The fuse wire shall be intact after the tests.

13.4 Condition of CB after the tests conducted as per clause no. 13.2.4, 13.2.5,

13.2.6, 13.2.7, 13.2.8, 13.2.9, 13.2.10, 13.2.11 and 13.2.12 of this specification shall conform as under :

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13.4.1 The mechanical functions and insulation of the CB shall be essentially in the

same condition as before the tests. The wear of the contacts shall not be disproportionate to its original size and shape. The CB shall be capable of carrying its rated normal current and also capable of performing its assigned duty provided in Clause 3.7 of the specification. The CB shall withstand for 1 min dry power frequency withstand voltage condition as per table below :

NOMINAL SYSTEM VOLTAGE OF CB (kV)

22 25 66 100/110 132 220 Power frequency withstand voltage

50

kV rms

95

kV rms

160

kV rms

230

kV rms

275

kV rms

460

kV rms

13.5 The tenderer may quote separately the charges for short circuit test duties, short

time withstand current and peak current withstand test, line charging breaking current tests, tests to prove rated TRV, short line fault test, out of phase making & breaking test, capacitor bank breaking current test, measurement of RIV level & special electrical test a per clause no. 13.2.4, 13.2.5, 13.2.6, 13.2.7,13.2.8, 13.2.9, 13.2.10, 13.2.11 and 13.2.1 No test charge shall be payable for any other tests.

13.6 If the prototype of the CB conforming to this specification has been approved for

earlier supplies to Indian Railways, testing of prototype again may be waived provided that no changes in the design and / or material used have been made. For this purpose the successful tenderer/ manufacturer shall approach Purchaser / DG (TI), RDSO, Lucknow with complete document to ascertain whether he equipment is identical to the prototype approved earlier. Once prototype approval is accorded after conducting all or part of the type tests by RDSO, the prototype approved earlier. Once prototype approval is accorded after conducting all or part of the type tests by RDSO, the prototype approval shall normally be valid for 5 years subject to the no change of design, material and process adopted prototype.

13.7 Only after clear written approval of the prototype is communicated by

Purchaser/DG/TI/RDSO/Lucknow to the successful tenderer / manufacturer, they shall take up bulk manufacture of the CB which shall be strictly with the same design, material and process as adopted for the prototype. In no circumstances the material from sources other than those approved in the designs / drawings and / or the prototype shall be used for bulk manufacture.

13.8 The successful tenderer / manufacturer shall furnish copies type test reports as per

relevant IS/IEC for all the important items including items listed at Annexure ‘B’. Suitable monogram in the form of engraving /embossing or other similar means shall be provided for each of these items to identify their manufacturer / source and shall be verified during the prototype inspection.

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13.9 Details of the important parts and sub-assemblies listed at Annexure –B shall be furnished by the successful tenderer /Manufacturer to DG(TI)/RDSO/Lucknow for record.

13.10 Routine tests

Every CB shall be subjected to the routine tests at the manufacturers’ works

as per clause 7 of IEC 60056(1987). Routine test reports of items / components used shall be made available to the testing authority. The routine tests comprise

(i) Rated one minute Power frequency dry withstand voltage test on the

main circuit as per clause no 13.10.1 (ii) Dielectric test on control and auxiliary circuits as per clause no

13.10.2 (iii) Measurement of contact resistance of main circuit as per clause no

13.10.3 (iv) Mechanical operation tests as per clause no 13.10.4 (v) Design and visual checks as per clause no 13.10.5

13.10.1 Rated one-minute power frequency dry withstand voltage test

The CB shall withstand dry power frequency voltage for one minute as per table below –

NOMINAL SYSTEM VOLTAGE OF CB (kV)

22 25 66 100/110 132 220 Power frequency withstand voltage

50 kV

rms

95 kV

rms

160

kV rms

230

kV rms

275

kV rms

460

kV rms

13.10.2 Dielectric tests on control and auxiliary circuits

The control and auxiliary circuits shall withstand 2000 V ac for one minute after disconnecting spring charging motor. The spring charging motor shall withstand 1500 V ac for 1 minute.

13.10.3 Measurement of contact resistance of the main circuit

The resistance shall be measured by dc voltage drop. The measured value shall not exceed 1.2 times the value of resistance recorded before temperature rise test during type test approved by DG (TI), RDSO.

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13.10.4 Mechanical operation test The test comprising five opening and five closing operations at each of the

rated, maximum and minimum control voltages i.e. at 110 V dc, +10% and –15% for closing operations and at 110V dc –30% for openings shall be performed . The contact travel characteristics shall be recorded for each closing and opening operation. The characteristics shall be within the tolerances specified in SOGP / type test values approved by DG(TI), RDSO.

13.10.5 Design & visual check

The CB shall be checked to verify its compliance with this specification. In particular following items shall be checked.

(i) Verification of dimension of equipment and assembly as per

drawings / data sheets approved by RDSO (ii) Verification of operation under local and remote.

(iii) Verification of clearance as per approved drawing.

(iv) Quality of painting / galvanizing of cubicles and mounting structure.

(v) Cubicle shall be dust and vermin proof conforming to IP 55 of IS

: 2147 (1962) (vi) Fasteners used in various assemblies shall be of stainless steel for

12mm dia or below and those above 12mm may be hot dip galvanized or stainless steel.

(vii) Verification of behavior under local electrical command while on

Local / Remote selector switch is in remote and vice versa. The CB should not operate.

(viii) Verification of manual opening and closing operation.

(ix) Verification of emergency device for opening of CB in the event of

failure as per clause 6.1.4.4.

(x) Verification of rated operating sequence.

(xi) Verification of interlocking.

The CB should not close either on remote or on local (mechanical or electrical) if key of the interlocking key is removed from the CB operating mechanism

541

(xii) Measurement of spring charging time. (xiii) Verification of contact wear indicator position.

(xiv) Measurement of current drawn by the motor.

(xv) Verification of function of tripping device in the event of 110V dc

supply failure (CTD)

(xvi) Verification of function of anti pumping device.

(xvii) Measurement of resistance of operating coils.

(xviii) Verification of SF6 gas alarm and lockout setting.

(xix) Verification of wiring and numbering of cable.

(xx) Verification of signal positions for close/trip and spring charged / spring discharged.

(xxi) Verification of make, type designation and rating of

parts/components.

(xxii) Verification of name plate details.

(xxiii) Verification of type and routine test reports of parts/components used.

(xxiv) Verification of tightness of sealed SF6 gas pressure system using

halogen detector. For this purpose polythene bags of appropriate size shall be tied enveloping the leakage points. after 24 hours the halogen detectors nozzle shall be pierced at the bottom of the bag to sniff any SF6 gas which might have leaked (in case SF6 gas CB). There shall not be any leakage of SF6 gas.

(xxv) Checking of proper fixing and support of springs, gas pipes, relays

gauges and tripping/closing coils.

(xxvi) Checking of free movement of armature of opening and closing coils.

(xxvii) Visual check of painting and galvanisation.

(xxviii) Checking of valve and pipe coupling.

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14.0 The tenderer shall specifically indicate in a statement attached with his offer, his compliance with each clause and sub-clause of this specification. A separate statement shall be attached with the offer indicating references to the clauses where the tenderer deviate there from together with detailed remarks/justification. If either the statement of compliance or statement of deviations is not attached with the offer, it is not likely to be considered. For the reason that it is an incomplete offer which can not be properly evaluated and compared with other offers, if any. If there are no deviations, a ‘NIL’ statement shall be attached.

15.0 Following drawings / documents to be furnished along with the tender :

(i) Full dimensioned General Arrangement drawing indicating clearances, fixing arrangement of the mounting structure on the foundation.

(ii) Schematic drawing. (iii) QAP for the equipment

(iv) ISO certification.

(v) List of essential plant, machinery and testing facilities.

(vi) Type test report for relevant rating as per RDSO / IEC specification.

(vii) List of supplies and performance report for the tendered equipment

from user railway /other customer.

(viii) The information furnished in the schedule of guaranteed technical performance, data and other particulars (Annexure –A) shall be complete in all respects. If there is any entry like ‘shall be furnished later’ or blanks are left against any item, the tender is not likely to be considered as such omissions cause delays in finalizing the tender.

16.0 Technical data and drawing to be furnished by successful tenderer/

manufacturer. 16.1 Details of the important parts and sub-assemblies listed at Annexure – B

shall be furnished by the successful tenderer / manufacturer to RDSO after award of contract

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16.2 The successful tenderer shall submit following details / dimensioned drawings as per Indian Railways’ standard in sizes of 210 mm x 297 mm or any integral multiples thereof for approval. (i) Name / Rating plate. (ii) General assembly showing mounting arrangement and overall

dimensions. (iii) Schematic and wiring diagram with explanation sheet.

(iv) Cross-section of interrupting chamber indicating the arcing/main

contacts and nozzle(s) or of the vacuum bottle as the case may be.

(v) Details of main, fixed and moving contacts and arcing contacts.

(vi) Operating and coupling mechanism of complete CB along with schematic diagram showing the mechanical linkages with explanation sheet.

(vii) Detailed drawings of spring for closing and opening.

(viii) SF6 gas circuit showing location of all gauges, pressure switches,

feed port, valves, interrupting chamber, piping coupling etc. with explanation sheet.

(ix) Full details of all sealing points with details of O-rings and gaskets.

(x) Details of Terminal Connector.

(xi) Details of Porcelain hollow insulators for support and interrupting

chamber.

(xii) Plain mass concrete foundation drawing and design calculations.

(xiii) Design calculation for structural safety along with details of supporting structure.

(xiv) Erection, commissioning, operation and maintenance manual.

(xv) Details of main parts / sub-assembly as per annexure B.

(xvi) Any other drawing considered necessary by the successful tenderer

/manufacturer and / or Purchaser. 16.3 Numbering of drawings shall be so structured as to give information about

total number of drawings, data sheets/instructions sheets relating to the

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contract for example a drawing designated as “D307 [4-12] sheet 2 of 5” denotes that :

(i) D 307 is the drawing No – the choice of which is left to the

successful tenderer. (ii) It is the 4th drawing out of a total set of 12 drawings/data sheet for

the contract.

(iii) It is the 2nd sheet out of total 5 sheets and 16.4 Cross reference of identical drawing if approved for earlier contract shall be

given in the drawing. Information required during erection, commissioning and maintenance of equipment shall be shown in greater detail.

16.5 After approval, six copies of approved drawings along with two set of

reproducible prints shall be supplied to each consignee. Drawings shall made in Auto CAD R 14, which is Window based for approval to RDSO. Two sets of approved drawings of hard copies, one copy of RTF and one set of floppies in Auto CAD R 14 shall be sent to RDSO for record.

16.6 Space earmarked for assigning RDSO’s drawing no. shall be available on

the right hand top side of each drawing. Numbering shall be allotted by RDSO after approval of the drawing.

16.7 Five copies of the approved Erection, Commissioning, Operation and

Maintenance Manual shall be supplied to each consignee, in case order is more than 10 nos. In case order is less than nos. 2 copies of manual shall be supplied. Two copies of manuals shall be supplied to the Purchaser /DG (TI), RDSO, Lucknow (India) for record.

16.8 Drawings approved by RDSO after prototype approval shall be submitted

for the future contracts also till the validity of prototype approval, with a clear certification on the drawing that design, process and material have not been changed in the design of the subject equipment from the prototype already approved by RDSO.

17.0 Erection, Testing and Commissioning The CB shall be erected and commissioned by the purchaser / manufacturer.

However, in case a defect / deficiency is noticed, the manufacturer / successful tenderer will have to depute his engineer for necessary remedial action without any cost to the Railways. In all the cases in which an order is placed either on new manufacturer of for a new type/design of the CB, the

545

services of manufacturer’s engineer shall be made available during the erection and proving/pre-commissioning test for the first order of their CB free of cost. For this purpose, prior intimation regarding the date and the location shall be given by the purchaser to the successful tenderer/manufacturer.

18.0 Spares 18.1 The tenderer shall furnish alongwith his offer, a list of spares (with cost)

recommended by him for maintenance of the CB for a period of ten years. The list should include gaskets/O-rings, parts which are likely to wear and items requiring replacement /replenishment, besides other items recommended by the manufacturer. The successful tenderer shall give an undertaking to the effect that he shall supply the required spares for the total life of the equipment (i.e. 25 years approx).

18.2 The tenderer shall furnish along with his offer, the cost of gas filling

arrangement, evacuation plant for SF6 gas and cost of SF6 in 10kg cylinder. 19.0 Training of Indian Railway’s engineers The offer shall include the training of two engineers of the Indian Railways

free of cost at the manufacturer’s works in India or abroad and at the maintenance depots /workshops on a Railway system or other public utility where circuit breakers of similar /identical design are in operation. The total duration of training for each engineer shall be 4 weeks of which approximately two weeks will beat manufacturer’s works and two weeks on a Railway system or other public utility. If the country of manufacturer is not India, the cost of travel to that country and back will be borne by the Indian Railways. Other details shall be settled at the time of finalizing the contract/Purchase Order.

20.0 After sales-service 20.1 The successful tenderer shall make necessary arrangements for closely

monitoring the performance of the CB through periodical (preferably once in two months during warranty period) visit to the locations where they are erected for observations and interactions with the operating and maintenance personnel of Indian Railways. Arrangements shall also be made by the successful tenderer / manufacturer for emergency / standby spare parts being kept readily available to meet exigencies warranting replacement so as to keep the CB in service with least down time.

20.2 Successful tenderer / manufacturer shall respond promptly and in a work man

like manner to any call given by Indian Railway for any assistance by way of attending to failures, investigations into the causes of failures including the tests, if any, to be done and such other items with a view to seeing that the CB serves the purpose for which it is procured. Besides, technical guidance to

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ensure proper operation and maintenance of the CB shall be constantly rendered.

21.0 Warranty 21.1 The successful tenderer/manufacturer shall warrant that all equipment shall be

free from defects and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally accepted standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

21.2 This warranty shall cover inspection of, payment for and acceptance of the

equipment, but shall expire 30 (Thirty ) months after the delivery at ultimate destination, or 24(Twenty four) months from the date of commissioning and proving test of the equipment at ultimate destination in India, whichever period expires earlier, except in respect of complaints, defects and/or claims notified to the successful tenderer/manufacturer within 3 (Three) months of the expiry of such date. Any approval or acceptance by the Purchaser of the equipment shall not in any way limit the successful tenderer /manufacturer’s liability.

21.3 The successful tenderer/manufacturer’s liability in respect of any complaint,

defects and /or claims shall not be limited to the furnishing and installation of replacement of parts free of any charge of the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer/manufacturer within 3 (Three) months of their being first discovered during the warranty period of 3 (Three) months from the date of expiry of warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damages as hereafter mentioned.

21.4 The successful tenderer / manufacturer’s shall, if required, replace or repair the

equipment of such portion thereof as is rejected by the Purchaser free of cost at the ultimate destination or at the option of the Purchaser. Successful tenderer / manufacturer shall pay to the Purchaser value thereof at the contract price or in the absence of such price at a price decided by the Purchaser and such other expenditure and damage as may arise by reason of the breach of the conditions herein specified.

21.5 All replacement and repairs that the Purchaser shall call upon the successful

tenderer / manufacturer to deliver or perform under this warranty shall be delivered and performed by the successful tenderer / manufacturer, promptly and satisfactorily and in any case within 2 (Two) months of the date of advice to this effect.

21.6 If the successful tenderer/manufacturer so desires the parts that are removed

may be taken over by him or his representative for disposal as he deems fit at

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the time of replacement with good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.

21.7 The warranty herein contained shall not apply to any material which shall have

been repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer/manufacturer, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

21.8 The decision of the Purchaser in regard to successful tenderer/manufacturer’s


22.0 Packing and dispatch 22.1 The various components of each CB shall be securely packed in wooden

crates/boxes. General packing list, together with weight and overall dimensions of each packing case shall be furnished for each CB indicating the following : Crate/Box No. Description of

item/component in the crate /box

Gross weight in kg

Approximate outside dimensions.

22.2 As far as possible, the gross weight of a crate/box shall be so kept that it

shall be possible to manually handle it by two persons. 22.3 In case of overseas supplies, packing shall be sea-worthy. 22.4 Necessary instructions for handling and storage shall also be furnished for

use at receiving end. 22.5 Porcelain housing/support insulator shall be supplied securely packed in

wooden crates. Not more than two porcelain housing/support insulators shall be packed in a crate in order to facilitate manual loading and un-loading.

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Annexure – ‘A’ Schedule of guaranteed performance technical and other particulars for 220 kV, 132 kV, 100kV, 110kV, 66 kV, 22kV and 25 kV and 25kV TP/DP/SP outdoor type SF6 gas and vacuum circuit breakers, Guaranteed particulars are to be established by test reports actual tests.

Sl. No.

Description Unit of measurement

Data

1. Maker’s Name 2. Country of manufacture 3. Manufacturer’s type designation

(i) Circuit breaker pole (ii) Operating mechanism

A. RATING

4. Number of poles No. 5. Rated voltage KV 6. Voltage rating class as per standard KV 7. Rated normal current A 8. Rated frequency Hz 9. Rated insulation level of the circuit

breaker (i) One minute dry and wet power

frequency withstand voltage (ii) Switching surge withstand

voltage (iii) Standard lightning impulse

withstand voltage 1.2/50 µS wave form (full wave)

(iv) Corona extension voltage

KV (rms) KV (p) KV (p) KV (rms)

10. Rated circuit breaking current

(i) Symmetrical at a recovery voltage of not less than the highest system voltage

(ii) Asymmetrical at a recovery voltage of not less than the highest system voltage.

(iii) Breaking capacity

KA KA MVA

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(symmetrical)

11. Rated making current KA peak 12. Rated line charging breaking current A 13. Rated cable charging breaking current A 14. Rated small inductive breaking current A 15. Rated capacitor bank breaking current A 16. Rated short time current

(i) for 1 s. (ii) for 3 s.

kA kA

17. Rated operating sequence 18. Rated transient recovery voltage kV 19. Breakage current on out of phase

condition KA (rms)

B. CONSTRUCTIONAL FEATURES 20. Number of breaks per pole 21. Total length of break per pole mm 22. Contact travel characteristics

(i) Length of contact travel (ii) Closing speed (iii) Opening speed (iv) Initial opening speed (v) Closing making speed (vi) Contact bounce (vii) Bounce duration

( Please furnish a graph showing contact travel characteristics )

Mm m/s m/s m/s m/s mm (max) s(max.)

23. Type of main contacts 24. Type of arcing contact

25. SF6 gas pressure

(i) Normal (ii) Minimum (iii) Maximum

kg/cm2

kg/cm2

kg/cm2

26. SF6 gas pressure at alarm kg/cm2 27. SF6 gas pressure at trip and lock out

kg/cm2

28. SF6 gas leakage rate (by weight) per year %

550

29. (i) If absorbent for decomposed SF6 gas product provided

(ii) Minimum quantity of absorbent per pole/

Yes / No Kg

30. Net weight of SF6 gas per pole/circuit breaker

Kg

31. Details of vacuum bottle (for Vac. CB)

(i) Make (ii) Type designation (iii) Voltage class (iv) Total weight

kV kg

32. Weight of pole assembly

(i) per pole (ii) per circuit breaker

kg kg

33. Weight of operating mechanism kg 34. Total weight of the circuit breaker kg 35. Minimum electrical clearance

(i) between poles (ii) between live part and earth

mm mm

36. Minimum sectional clearance between lowest live part and any part where a person may stand.

mm

37. Minimum height of bottom most part of any insulator from ground level

mm

38. Distance between centers of pole for TP & DP CB

mm

39. Overall dimensions of the circuit breaker complete with insulators, operating mechanism cubicle etc. mounted on the supporting structure.

(i) Length (ii) Width (iii) Height

Please furnish the General Arrangement drawing with overall dimension.

mm mm mm

C. OPERATING PARTICULARS 40 Closing time from the instant of closing

coil energisation (max.) ms

41. Opening time from the instant of trip coil energisation (max.)

ms

42 Make Time (max.) ms

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43. Arcing Time

(i) At rated normal current (ii) At rated short circuit breaking

current (iii) At 60% of short circuit

breaking current (iv) At 30% of short circuit

breaking current (v) At 10% of short circuit

breaking current

ms ms ms ms ms

44. Critical current kA 45. Total break time from the instant of trip

coil energisation to the final extinction of arc

(i) At rated normal current (ii) At short circuit breaking current

ms ms

46. Rated restriking voltage (i) Amplitude factor (ii) Rate of rise at natural

frequency (iii) Type and device used to limit

rate of rise of restriking voltage

KV

47. Minimum time interval (t) permissible between successive “CO” operation after first auto reclosure.

s

48. Number of operations (close and open) the circuit breaker can perform with the available stored energy

No

49. Number of operations permissible without change of SF6 gas / vacuum bottle (min)

(i) At 50% of rated current (ii) At 100% of rated current (iii) At 50% of short circuit


breaking current

No. No. No.

50. Number of operations permissible without replacement / inspection of contacts (min)

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(i) At 50% of rated current (ii) At 100% of rated current (iii) At 50% of short circuit


breaking current (A graph establishing the above two parameters at SN 49 and 50 should be enclosed)

No. No. No. No.

51. First pole to clear factor (In case of TP and DP CBs)

D. OTHER TECHNICAL PARTICULARS

52. Maximum rise at temperature over an ambient of 50ºC when carrying its normal rated current continuously.

(i) Main contacts in SF6 gas (ii) Terminal when connected with

external connectors (iii) Metal parts acting as springs (iv) Metal parts in contact with

insulators (v) Auxiliary contacts (vi) Operating coils

ºC ºC ºC ºC ºC ºC

53. Power required for tripping /closing (max)

W

54. Control circuit voltage with permissible voltage variation

(i) Closing coil (ii) Tripping coil (iii) Contactors (if any) (iv) Any other item (for which the

tenderer feels that the voltage is to be maintained within certain limits)

V.dc + % / -% V.dc + % / -% V.dc + % / -%

55. Type of tripping / closing mechanism

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56. Manual tripping / closing mechanism (lever push button or any other device)

57. Spring Charging Motor (i) Make and type designation (ii) Rating (iii) Voltage with permissible variation (iv) Power frequency withstand voltage (v) Class of insulation (vi) Time required by the motor to charge the spring(s) fully

(vii) Power required at normal controlled voltage to charge the spring (viii) Mode of protection (ix) Specification for design and testing

KW V KV(rms) S W IS / IEC

58. Springs – Closing / Opening

(i) No. of springs (ii) Type (compression / tension) (iii) Specification for design and

testing

IS / IEC

59. Porcelain Insulators

(i) Makers name and type designation (ii) Minimum creepage distance

Support Insulator Interrupting Chamber Insulator

60. Insulation grade of PVC control wiring cable

V

61. Approximate height of the close/trip switch and socket for spring from ground level

mm

62. Details of Operation counter : (i) Make and type (ii) No. of digits

63. Auxiliary Switch (contacts)

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(i) Make and type (ii) Normally open contacts (iii) Normally closed contacts (iv) Continuous rating of contacts (v) Breaking capacity of contacts

at 220 V dc with inductive load

(vi) Life (No. of operations)

Total Spare Total Spare A A No.

64. Limit switch (for spring charging motors)

(i) Make and type (ii) Continuous rating of contacts (iii) Breaking capacity of contacts

at 220 V dc with inductive load

(iv) Life (No. of operations)

A A No.

65. Gas pressure indicator and pressure switch

(i) Make and type designation (ii) Range and list count (iii) Governing specification

66. Sulphur Hexa Fluoride gas (SF6) Governing specification

IS/IEC

E. OTHER DETAILS

67. Is the circuit breaker having a common drive (for TP and DP CB) ?

Yes/No

68. Are the main and arcing contacts easily replaceable ? (for SF6 CBs)

Yes/No

69. Is signal provided (audible/visible) in the event of drop of SF6 gas to a pre-determined value ?

Yes/No

70. Is a device for tripping the circuit breaker, in the event of 110 V dc supply failure, provided (Indicate the type of device) ?

CTD/No volt relay

71. Does provision of trip circuit supervision exist ?

Yes/ No

72. Is electrical anti-pumping device Yes / No

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provided ? 73. Is mechanical closing device provided ? Yes / No 74. Is local electrical closing & tripping

device provided ? Yes / No

75. Is manual closing & tripping device provided ?

Yes / No

76. If terminal connector for CB provided ? Yes / No 77. Is mechanical tripping device provided ? Yes / No 78. Is handle/crank for manual charging of the

closing spring provided ? Yes / No

79. Is operating counter visible without opening the mechanism door ?

Yes / No

80. Are the mechanical close and open indicator provided ?

Yes / No

81. Is two position LOCAL/REMOTE switch provided ? Indicate type – (Spring loaded)

Yes / No

82. Is the CB trip free ? Yes / No 83. Are electrical and mechanical interlocks

with keys provided ? Yes / No

84. Is the operating mechanism housed in a dust, weather and vermin proof cabinet of 2 mm thick sheet steel construction ? (indicate the protection)

Yes / No

85. Is a heater provided for prevention of condensation of moisture in the operating mechanism box ?

Yes / No

86. Is three pin socket and inspection lamp provided ?

Yes / No

87. The size and number of cable glands provided

Dia No Dia No

88. What is the insulation grade of PVC cable used ?

V

89. Are the cables terminated with crimped lugs ?

Yes / No

90. Is ac & dc and +ve & -ve wiring completely segregated ?

Yes / No

91. Are the terminal blocks for wiring dust proof and provided with unbreakable transparent shrouds ?

Yes / No

92. Are the two distinct earthing terminals provided with indication for earth ?

(i) Support structure (ii) Operating mechanism cubicle

Yes/No Yes/No

93. Are fasteners of 12 mm dia and less Yes / No

556

exposed to atmosphere of stainless steel ? 94. Are the fasteners of more than 12mm dia

of stainless steel or mild steel hot dip galvanized ?

Yes / No

95. If supervision for erection testing and commissioning is provided ?

Yes / No

96. If training of two IR engineers be arranged for a total period of 4 weeks ?

Yes / No

97. Is warranty provided as per clause No. 21 ?

Yes / No

98. Has list of spares been furnished ? Yes / No 99. Has list of special maintenance tools

furnished ?

Yes / No

100. Has erection, operation and maintenance manual furnished ?

Yes / No

101 Does provision for slow opening and slow closing exists ?

Yes / No

102. Have closing/tripping springs properly fixed to prevent their misalignment ?

Yes / No

103. If any deviations asked ? Give number of clauses where deviation has been asked for .

Yes / No

104. Is any external indicator for contact wear provided ?

Yes / No

105. What are the test certificate attached ? please list out.

106. If painting of steel surfaces exposed to weather, done to RDSO’s specification ?

Yes / No

107. If the support structure and operating mechanism cubicle hot dip galvanized ?

Yes / No

108. Quantity of zinc for galvanization Kg/m2

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Annexure – ‘B’

The following information shall be furnished by the manufacturer / supplier Sr.No. Description Unit of measurement Data 1. Fixed main contact :

(i) Description and type designation

(ii) Make (iii) Identification mark (iv) Item drawing No. (v) Material and specification No.

2. Moving main contact (i) Description and type

designation (ii) Make (iii)Identification mark (iv) Item drawing No. (v) Material and specification No.

3. Fixed arcing contact : (i) Description and type

designation (ii) Make (iii)Identification mark (iv) Item drawing No. (v)Material and specification No.

4. Moving arcing contact : (i) Description and type

designation (ii) Make (iii) Identification mark (iv) Item drawing No. (v)Material and specification No.

5. Nozzle – Main and auxiliary (if any): (i) Description and type

designation (ii) Make (iii) Identification mark (iv) Item drawing No. (v) Material and specification No

6. Vacuum Bottle

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(i) Description and type designation

(ii) Make (iii) Rating (iv) Identification mark (v) Item drawing No. (vi) Geometry of contact (vii) Governing specification

No. (viii) Weight (ix) Level of vacuum adopted (x) Level of current chopping (xi) Shelf life

7. Auxiliary contact

(i) Description and type

designation (ii) Make (iii) Identification mark (iv) Item drawing No. (v) Governing specification

No. (vi) Rating :

(a) Voltage (b) Continuous current (c) Breaking and making

current (d) Electrical &

Mechanical life (No. of operations)

8. Motor limit switch :

(i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification

No. (vi) Rating :

(a) Voltage (b) Continuous current (c) Breaking and making

current (d) Electrical &

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Mechanical life (No. of operations)

9. MCB’s (i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification

No. (vi) Rating :

(a) Voltage (b) Continuous current (c) Breaking and making current (d) Electrical & Mechanical life (No. of operations)

10. Spring charging motor

(i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification

No. (vi) Rating :

(a) Voltage (with permissible variation) (b) Wattage (c) Power frequency voltage withstand (d) Class of insulation (e) Time required by the motor to charge the spring fully (max.) (f) Power required at normal control voltage to charge the spring (g) mode of protection

560

11. Spring Closing Tripping Other

(i) Description and type (ii) Type designation (iii) Make (iv) Identification Mark (v) Governing specification (vi) Drawing No. (vii) Rating

(a) No. of springs (b) Type (compression/tension/spiral (c )No. of turns (d) Gauge (e) External diameter (f) Stiffness (g) Material (h) Force developed in Fully charged position

12. Operating Coil : Closing Tripping

(i) Description and type (ii) Type designation (iii) Make (iv) Identification Mark (v) Governing specification (vi) Rating :

(a) Operating voltage (with permissible variation )

(b) Power (c) Resistance at 20ºC (d) Class of insulation

13. 14.

Operation Counter : (i) Description and type (ii) Type designation (iii) Make (iv) Identification Mark (v) Governing specification (vi) Number of digits Gas pressure indication and Pressure Pressure pressure switch indicator switch

561

(i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification (vi) Range and least count

15. Heater :

(i) Description and type (ii) Type designation (iii) Make (iv) Identification mark

(v) Governing specification Rating : (a) Voltage (b) Power (vi) Make and type designation of thermostat

V – ac W

16. Interlock : (i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification (vi) Electrical rating of switch used

V dc A

17. Terminal connector :

(i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification (vi) Rating

(a) Voltage (b) Current / Power

V ac A

18. Resisters : (i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification (vi) Rating : (a) Voltage

V

562

(b) Current / Power A / W 19. Relays and contactors (please furnish details for

all the type of relays / contactors used ) : (i) Description and type (ii) Type designation (iii) Make (iv) Identification mark (v) Governing specification (vi) Rating : (a) Operating voltage range (b) Pick up voltage (c) Drop out voltage (d) Burden (e) Auxiliary contact rating

(f) Guaranteed life 1. Electrical 2. Mechanical

(g) Wiring details (drawing No.)

V ± V V VA No. of operations No. of operations

20. ‘O’ Ring and Gasket (please furnish details for all the varieties ) (i) Description and make (ii) Dimension / drawing No. (iii) Material and specification

21. Valves and couplings : (i) Description and type (ii) Type designation (iii) Governing specification

22. Shock absorber : (i) Description and type (ii) Type designation (iii) Identification mark (iv) Governing specification (v) Type brand and specification of fluid used (if any)

563

Addendum / Corrigendum Slip No.1 of August 2001 for specification No. TI /SPC / PSI /CB / 0000 for out door circuit breaker for Railway Traction substation. 1. Page No. 3 Clause No. 2.3 Please read the line 8 - “The change are only – this specification” as follows.

“The changes are in respect of following . (i) Line charging breaking current test has been included. (ii) Operating sequence of 25 kV CB has been changed from O-0.3s – CO – 30s- CO to O-0.3s – CO-15s –CO (iii) Ground clearances has been revised. (iv) Supervision of erection and commissioning of CB has been revised.”

2. Page No. 10 & 11 Clause No. 5.1 Rating and other particulars. The table under this clause be changed as given below.

S. No.

Particulars RATED SYSTEM VOLTAGE (kV) 22 25 66 100/110 132 220

1 2 3 4 5 6 7 8 (vi) Rated normal

current 2000 A 1600 A 1250A 1600 A 1600 A 2000 A

(vii) Rated short circuit breaking current

25 kA 20 kA 31.5 kA

40 kA 40 kA 50 kA

(viii) Rated breaking capacity (symmetrical) (i) Single pole (ii) Two pole (iii) Three pole

-

600 MVA

-

550 MVA

550 MVA -

-

2284 MVA

3956 MVA

-

4920 MVA

8522 MVA

-

5800 MVA

10046 MVA

-

12250 MVA

21218 MVA

(ix) Out of phase breaking current

6.25 kA

(rms)

5 kA

(rms)

7.9 kA

(rms)

10 kA

(rms)

10 kA

(rms)

12.5 kA

(rms) (xiii) Rated making

current 62.5 kA (peak)

50 kA (peak)

78.8 kA (peak)

100 kA (peak)

100 kA (peak)

125 kA (peak)

(xvi) Rated short time withstand current

25 kA (rms) for 3 s

20 kA (rms) for 3s

31.5 kA (rms) for 1s

40 kA (rms) for 1s

40 kA (rms) for 1s

50 kA (rms) for 1s

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3. Page No. 33 Clause No. 13.2.5 -Rated short time withstand current and peak

withstand current test. The table under this clause be changed as given below. NOMINAL SYSTEM VOLTAGE OF CB (KV) 22 25 66 100/110 132 220 Value of current & duration rms peak

25 kA for 3s 62.5 kA

20 kA for 3s 50 kA

31.5 kA for 1s 78.75 kA

40 kA for 1s 100 kA

40 kA for 1s 100 kA

50 kA for 1s 125 kA

4. Page No. 33 Clause No. 13.2.9 Out of phase making and breaking test. The table

under this clause be changed as given below : NOMINAL SYSTEM VOLTAGE OF CB (KV) 22 25 66 100/110 132 220 Current rms

6.25

5 kA

7.9 kA

10 kA

10 kA

12.5 kA

Recovery Voltage

----------------------------NO CHANGE -----------------------------------

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Addendum / Corrigendum Slip No.2 (July 2003) to specification No.TI /SPC / PSI /CB / 0000 for out door circuit breaker for Railway Traction substation. This is to be read with A&C Slip No.1 of August 2001. The Items given below are to be changed as indicated :- 0.0 The following changes are made on Page No.12, 13 and 14 viz. Clause No.5.1 – Rating and other particulars :-

S. No.

Clause No./Page No./

Particulars

RATED SYSTEM VOLTAGE (kV) 22 25 66 100/11

0 132 220

1. 5.1-vi, page 13 Rated normal current.

2000A 1600A or

2000A**

1250A 1600A 1600A 2000A

2. 5.1-vii, page 13 Rated short circuit breaking current.

25 kA 20 kA 31.5 kA 40 kA 40 kA 40 kA

3. 5.1-viii, page 13 Rated Breaking Capacity (MVA) i) Single Pole ii)Double Pole iii)Triple Pole

-- 600 --

550 550 --

-- 2284 3956

-- 4920 8522

-- 5800 10046

-- 9800 16974

4. 5.1-ix, page 13 Out of Phase breaking current.

6.25 kA

rms

5 kA rms

7.9 kA rms

10 kA rms

10 kA rms

10 kA rms

5. 5.1-xiii, page 13 Rated making current.

62.5 kA

(Peak)

50 kA (Peak)

78.8 kA (Peak)

100 kA

(Peak)

100 kA (Peak)

100 kA

(Peak)

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RDSO Specification No. TI / SPC / PSI / CB / 0000 for Circuit Breaker for Railway Traction substation The following amendments are made in addition to the addendum and corrigendum slips issued to the specification by RDSO : Sl.No. Para No. Amendment 1. Para 1.3 The para is modified as under :

“ When pre-commissioning and commissioning tests on CB are being conducted, the manufacturer’s engineer shall be available at site. For this purpose, prior intimation regarding the date and the location of the tests shall be given by the successful bidder to the manufacturer.

2. Para 3.1.1 In line 10, substitute 50 km & 80 km with 6.5 km & 25 kms respectively.

3. Para 3.1.2 In line 2, delete the word “Interrupter”

In line 10, delete the word “feeder” In line 11, substitute “Interrupter” with “feeder circuit breaker”

4. 3.7.1 (iii) Delete the words “through interrupter for voltage of

25 kV” after OHE in line 1 and add “of each track” after OHE in line 1.

5. 4.1 (i) Substitute 50°C with 45°C (ii) Substitute 0°C with 5°C (iii) Substitute 40°C with 35°C 6. 4.1 (ix) Substitute 200 kgf/m2 with 112.5 kgf/m2

7. 6.1.2.1 delete the last sentence in para 1 8. 7.1 In line 3, substitute “200 kg/ m2”

with “112.5 kg/m2” In line 7, substitute “RDSO” with “Purchaser” 9. 7.2 In line 2, substitute “RDSO” with “Purchaser”. 10. 8.0 In line 4, substitute 200 kg/ m2 with 112.5 kg / m2 In line 9, substitute DG (TI) RDSO with Purchaser.

567

11. 11.2.2 In line 4, delete the words “Supplied loose ” In line 3, substitute the word “ for mounting by Purchaser” with “mounted”

12. 11.2.3 In line 4, delete the words “Supplied loose”

In line 4, substitute the word “ for mounting by Purchaser” with “mounted”

13. 11.2.8 Deleted 14. 11.3.2 In line 4, delete the words “supplied loose ”

In line 4, substitute the word “for mounting by the Purchaser” with “mounted” In line 5, Add “ / Purchaser” at the end after RDSO.

15. 11.3.3 In line 1, substitute the word “loose” with the word “of”

In line 2, Delete the word “by the Purchaser”

16. 11.3.4 In line 7, delete the word “by the Purchaser” 17. 11.3.9 Delete the 1st sentence in the para. 18. 11.3.10 In line 1, substitute the word “only” with the word

“preferably” 19. 13.1.1 In line 2, 3 & 4 add “Purchaser /” before the word RDSO. 20. 13.5 Delete the words starting with “The tenderer may

quote……….… upto 13.2.11 and 13.2.12. Delete the word “other” in the last sentence. 21. 13.6 In line 2, delete the word “Indian” 22. 13.9 In line 3, add “Purchaser /” before DG (TI) / RDSO 23. 13.10.3 In line 3, add the word Purchaser /” before the word DG (TI) / RDSO 24. 13.10.4 In line 7, add the word “Purchaser /” before the word DG

(TI) / RDSO 25. 13.10.5 (i) Add “Purchaser /” before the word “RDSO” 26. 16.1 In line 2, add “Purchaser/” before the word “RDSO”

568

27. 16.5 In line 3 & 5 add the word “Purchaser/” before the word

“RDSO” 28. 16.6 Delete the para. 29. 17.0 In line 1, substitute the word “Purchaser” with“Contractor” 30. 21.1 Para 2 of the clause is modified as follows :

“The warranty period shall be 36 (Thirty six) months from the date of delivery of the equipment at the ultimate destination or 24 (Twenty four) months from the date of commissioning of the equipment whichever period expires earlier.”

In para 3, of the clause delete, from the line, 8, 9 & 10 the words “of 3 (three) months…….. mentioned. In para 4, in line 1, delete the words “if required” In line 3, 4, 5, 6 & 7 delete the words “or at the option…………….herein specified”

569

570

lR;eso t;rs

G O V E R N M E N T O F I N D I A M I N I S T R Y O F R A I L WA Y S

Specif ication No. TI/SPC/PSI/PROTCT/4050

FOR CONTROL AND RELAY PANEL

FOR PROTECTION SYSTEM

OF MUMBAI SUBURBAN AREA

FOR 50 H Z AC T RACTION POWER SUPPLY SYSTEM

INCLUDING PARALLEL OPERATION ON 25 KV SIDE

OCTOBER 2005

ISSUED BY

RESEARCH DESIGNS & STANDARDS ORGANISATION, MANAK NAGAR , LUCKNOW-226011.

571

Index

I T E M

N O

H E A D I N G PA G E

1 . SP E C I A L R E Q U I R E M E N T F O R M U M B A I S U B U R B A N A R E A

2 . SC O P E

3 . T R A C T I O N P O W E R S U P P LY S Y S T E M

4 . SE R V I C E C O N D I T I O N S

5 . D E S I G N F E A T U R E S

6 . SC H E M E O F P R O T E C T I O N

7 . D E T A I L S O N P R O T E C T I O N O F I N C O M I N G H.V. L I N E S

8 . D E T A I L S O F P R O T E C T I O N S C H E M E FO R T R A C T I O N

T R A N S F O R M E R

9 . D E T A I L S O F S C H E M E O F P R O T E C T I O N F O R 25 KV

O V E R H E A D E Q U I P M E N T

10 . INSPECTION AND TESTING

11 . ERECTION, COMMISSIONING AND PROOVING

TESTS.

12 . TECHNICAL DATA AND DRA WINGS

13 . OPERATION & MAINTENANCE, INSTRUCTIONS &

TRAINING

14 . WARRANTY

15 . SERV ICE SUPPORT AFTER W ARRANT Y AND AM C

16 . SPECIFICAT ION CONFIRMATION

17 . TENDER’S CREDENTIALS

18 . IMPORTED RELAYS

572

ANNEXURES

A N N E X U R E 1 A B B R E V I A T IO N S U S E D. 50

A N N E X U R E 2 D E F I N I T I O N S 51

A N N E X U R E 3 G O V E R N I N G S P E C I F I C A T I O N S 53

A N N E X U R E 4 SC H E D U L E OF GU A R A N T E E D PA R T I C U L A R S 55

A N N E X U R E 5 MA T E R I A L SC H E D U L E 67

A N N E X U R E 6 M U M B A I A R E A P O W E R S U P P LY S C H E M A T I C 71

A N N E X U R E 7 PROTECTION SCHEME FOR TSS, SSP

A N D SP 72

573

1. 0 SPECIAL REQUIREMENT FOR MUMBAI SUBURBAN ARE A Electric traction in suburban areas of Mumbai presently employs 1500 Volts D.C. and the network is being converted to utilize 25 kV AC for the railway traction system. In the existing D.C system, the overhead equipment (OHE) is supplied power at 1500 volts from rectifier fed traction sub-stations (TSS) with normally no sectioning; the sub-stations thus are connected in parallel. In an event of failure of one of the TSSs the supply is maintained from adjacent TSSs. Total supply interruption for sub-urban trains (EMUs) and the D.C. locomotive hauled main line trains is rare. The conventional 25 kV AC 50 Hz traction system on Indian Railways draws power from two of the three phases of the incoming E.H.V. lines and transforms it to 25 kV, earthing one of the secondary terminals of the transformer. Power is drawn from different phases at adjacent TSSs, cyclically, to balance the load. The separation of phases is carried out on the OHE contact wire system by provision of “neutral sections” which do not draw power and mechanical continuity for passage of the pantograph of the motive power unit is ensured. The drivers of trains are instructed to switch off the on-board 25 kV circuit breakers to prevent flashovers while the pantographs negotiate the neutral sections. Tripping of the feeder circuit breakers (CB) is associated with supply interruption over the feed zone. The train movement (traffic density) in the sub-urban area of Mumbai is very high and the requirements are therefore different from those of the conventional system with emphasis on a protection system offers a reliable OHE supply, is capable of isolating the shortest possible section in the fastest possible manner and localize a fault with minimal human intervention. The spacing of signals and stations at short intervals and the short headway between trains does not lend itself to the adoption of the conventional 25 kV AC supply scheme, drawing power from different phases and the electrical separation on 25 kV side through neutral sections. This specification is prepared on the basis of earlier specification No.TI/SPC/PSI/PROTCT/3003 and considering the suggestions / recommendations of consultant to MRVC (Frischmann Prabhu (India) Pvt. Ltd. EPD Consultants, UK and DE-Consultant, Germany) along with latest developments in protection relays and experience of abroad railways.

1.1 Salient requirements for the Mumbai area summarized below.

a) Traction supply for Mumbai area at different traction substation shall be taken

at 110 kV from power supply authority and up to three adjacent traction substations which draw power from one supply authority and from the same phase may be operated in parallel on the 25 kV side of the traction transformers. In service, the “neutral sections” separating the sectors shall be kept live, there-by avoiding the operational and safety implications with the conventional neutral sections, during exigencies, however, the neutral sections can be activated by operating the specific switches/ interrupters/ CBs.

574

b) TSSs are spaced at distances of 6.5 to 20 kms.

c) Some of the sub-sectors are short, about 1 km.

d) SP/SSP shall be provided with CB’s in lieu of interrupters so that the smallest possible section can be isolated & faults localized automatically, with minimal intervention by the personnel on duty in the control room.

e) The motive power employed on trains, including EMUs, shall be with drives

based on IGBT or GTO based 3 phase converters or silicon rectifier based D.C. Traction motor locos. The 3 phase drive motive powers are capable of regeneration during braking operation. There is possibility of the regenerative currents being fed back into the grid.

f) The starting currents in case of a number of EMUs starting together at times

may exceed the fault current in event of high impedance faults.

g) OHE System in Mumbai area is of 4 to 6 lines with arrangement at SSP/SP of bus type as given in the enclosed drawing at Annexure-6.

h) OHE is of varying configuration and its line parameters are expected to be

different for different sections. Values of R and X may undergo change with replacement with different size of wires or addition of new tracks. As parameters of some of the sections may not be available, the successful tenderer will be required to determine/measure the critical parameters needed for the protection scheme as may be necessary.

i) In the Railway traction substation HV circuit breakers shall be provided on the

incoming feeder lines along with bus coupling breaker with associated protection as different from the conventional 25 kV Traction sub-stations.

1.2 PRE -BID MEETING A pre-bid meeting shall be arranged by the purchaser, with eligible tenderers and associating RDSO & Rlys. for clarification on particular requirements of protection to this specification, parameters of OHE (per km. resistance, reactance values) required for its functioning, site conditions, erection and commissioning and field proving etc.

It is advised that tenderers visit the sites/sections and familiarize themselves with the local conditions and understand the requirements of the system in detail, before tendering their bids. Clarifications as may be necessary shall be obtained from the purchaser. After the award of the contract the tenderer shall be fully responsible for successful integration of the protection scheme with the associated scheme of equipment in the switchyard (TSS, SP, SSP) and the RTUs and any items later considered as essential for successful integration, shall be within the scope of the supply and work of the tenderer. In case of any consultancy

575

required by the tenderer for successful commissioning, tenderer shall arrange it within his scope.

2.0 SCOPE 2.1 This specification applies to the design, development, manufacture, supply, erection and field proving & monitoring of “numeric/processor based control and relay panel” complete with numeric/ micro processor/ static protective relays, for use in the traction substations and SSP/SPs for control of 110 kV and 25 kV circuit breakers, 25 kV interrupters and protection of 220 or 132 or 110 kV single phase transformers with 25 kV nominal secondary voltage, all substation equipment, 25 kV over head equipment (OHE) feeders and capacitor bank (if asked for by the purchaser in the tender). 2.2 Accordingly, control & relay panels will be required at supply control posts as

follow.

(i) Traction substation to protect and control incoming HV lines*, traction transformers, 25 kV feeders and 25 kV capacitor banks (if required by the purchaser).

*NB: Protection of HV incoming lines shall be supplied by the concerned supply authority in a separate panel giving all the necessary control, indication and alarm contacts on the terminal junction inside the panel. However HV bus bar protection and the connections from the protection panel of supply authority to the C&R panel for Railways shall be within scope of the tenderer.

(ii) SSPs to protect and control 25 kV feeders. (iii) SPs to protect and control 25 kV feeders.

2.3 Scope of supply shall include all parts, fittings and accessories of the control & relay panel required for normal functioning of the protection system. The panel shall be complete with numeric-processor based protection package for traction transformers, feeders and for capacitor banks (optional). The protection relays shall have communication features and necessary interface equipments are to be provided for its normal functioning and to ensure sending the fault waveform data stored in the relays at TSS/SSP/SP to remote control centre through SCADA.

2.4 The control panel have been classified into four categories for the purpose of this specification, viz., TYPE –I: Required at 220/25 kV or 132/25 kV or 110/25 kV traction substations with single or double ended feeding with line tripping and line sectioning facilities. (with or without capacitor banks as required by the purchaser)

576

TYPE-II: Required at 25 kV SP with CB and/or with line tripping and line sectioning facilities suitable for single ended or double ended feeding. TYPE-III: Required at 25 kV SSP with CB and/or with line tripping and line sectioning facilities. TYPE –IV: For yards, car shed or other areas not covered in the above types. 2.5 The control panels offered shall be an integrated one complete with relays, meters,

control switches, wiring and all accessories and materials necessary for efficient control and protection of equipment and feeders. All accessories and materials shall be deemed to be within the scope of this specification whether specifically mentioned or not.

2.6 The specification covers the protection of TSS, SP & SSP and the related substation

equipment and the OHE. Protection of incoming feeder to the TSS from reverse feeding the faults in the incoming line is included. The specification excludes the protections for HV incoming lines provided by the electric supply authority as part of the service connection scheme, however, necessary control/indication/alarm connections/terminations, inter-tripping and inter-locking is required to be ensured as specified in clauses 5.1.1.

2.7 Purchaser may consider any proposal for an improvement in the protection scheme.

However for all such proposals the tenderer shall be required to furnish full technical detail, drawings etc. to satisfy the purchaser.

2.8 Any changes required in relays and C&R panel during or arising as a result of

commissioning /field proving tests shall be continued to be governed by this specification and within the scope of supply by the tenderer.

3.0 TRACTION POWER SUPPLY SYSTEM 3.1 General scheme of traction power supply.

Power in Mumbai area shall be received from the grid network of the supply authority at 110 kV at individual traction substation (TSS) with two Nos. traction power transformer 25 kV power supply for traction is drawn through a single phase step-down traction power transformer, the primary winding of which is connected to any two nominated phases of the incoming three phase lines. On the secondary side, one of the two terminals of the 25kV winding is connected to the traction overhead equipment, while the other is solidly earthed and also connected to the running traction rails. The method of connection to the running traction rails depends on type of signaling track circuit used, and as follows.

577

a) Through an impedance bond offering negligible impedance for power frequency

AC current in case of AFTC. b) In case of DC track circuiting it shall be directly connected to the traction return

rail. 3.1.1 Each transformer shall have its associated circuit breakers on the primary and 25

kV sides, with a separate set of 25 kV circuit breakers called “Feeder Circuit Breakers” for the traction OHE lines; refer Annexure 6. These CB’s can be of outdoor or indoor type, and employ SF6, vacuum or may be gas insulated type switchgear.

3.1.2 On some sections (single ended supply), adjacent TSS shall be fed from different phases of the three-phase system in rotation. Neutral sections in front of sectioning and paralleling post (SP) shall be provided on the 25 kV OHE for segregating the different phases. In between the TSS and SP, sub-sectioning posts (SSP) are provided for sectionalizing and fault localization. The purchaser shall enclose their detailed general supply diagram for the detailed understanding of the tenderer. 3.1.3 On other sections the adjacent TSSs are fed from the grid on the same phase and shall feed the OHE in parallel. In such an arrangement, at SPs, bridging circuit breakers shall normally be kept closed. In the event of a fault, the fault would be simultaneously fed from adjacent TSS, which are in parallel operation. Refer Annexure 6 for details. 3.1.4 The supply to the OHE can be switched ON/OFF through circuit breakers which can open or close automatically on fault. The circuit breaker provided at the TSS, SSP, SP can clear the fault in their sub-sector. The other CBs of the adjacent sub-sectors shall not trip normally in case of such faults. 3.1.5 Normally power supply from a TSS extends up to the SP on either side of the substation. But in case of an emergency necessitating total shut down of the substation, power supply from adjacent TSS on either side of the failed substation can be extended up to the failed substation by closing the bridging CB of the 2 SPs. Also under certain emergency conditions the supply can also be extended beyond the failed TSS up to the next SP. 3.1.6 The sectioning posts may be provided with conventional overlap type, PTFE type or any suitable type including automatic switched neutral sections. Neutral Section at the SP between the TSSs proposed to be operated in parallel shall be of such type to facilitate parallel operation and without tripling / closing of the loco/EMU circuit breakers during its negotiation.

578

3.2 Nature of traction load and faults on the system. 3.2.1 The traction load is frequently and rapidly varying between no load and overload. The TSS equipment is subject to a number of earth faults/short circuits. 3.2.2 The AC electric rolling stock/ AC-DC electric locos / EMUs are fitted with, for conversion of AC to DC, single phase bridge-connected silicon rectifiers with smoothing reactor for feeding the dc traction motors. The rectifiers introduce harmonic currents on the 25 kV Power supply. Also there are EMU’s / locomotives with GTO Pulse width modulation devices, in place of silicon rectifiers. Typical percentages of the current harmonics present in the traction current with electric rolling stock are as follows:

TABLE NUMBER - 1:

Harmonic currents Generated by IR Locomotives / 3 phase EMU’s

S. No

Harmonic order With Diode Rectifier

Three Phase EMU’s with GTO’s*/ IGBTs.

1. 3rd harmonic(150 Hz) 15% The maximum harmonic current of the individual harmonics at no time shall exceed 0.5 Amps except for 3rd harmonic which shall have maximum value of 5 Amp.

2. 5th harmonic(250 Hz) 6% 3. 7th harmonic (350 Hz) 4% 4. 9th harmonic(450 Hz) - 5. 11th harmonic (550 Hz) - THD’s 16.64%

*The GTO type of EMU’s / locomotives produce substantial 2nd harmonic currents which may go up to 10 % of fundamental current at times.

The average power factor of an electric locomotive and electric multiple units

generally varies between 0.7 lagging to unity. 3.2.3 The EMUs rakes are generally formed of 9, 12 and 15 coaches. One three coach unit can take starting currents of up to 70 amps on 25 kV side. Under normal running condition such a 3 car rake draws 40 amps. Such rakes are also capable of producing regeneration current up to 40 Amps per unit of 3 coaches. 3.2.4 In case of locomotive hauled trains, a 3-phase electrical locomotive, at full power, draws up to 270 amps of current from the OHE; the current produced during regenerative braking is of the order of 150 amps. Normally one such locomotive hauls one train but if gradients are high and loads are more a maximum of 2 locomotives in multiple operation may be employed.

579

3.2.5 The number of faults/short circuits, per TSS, in the conventional 25 kV AC system vary between 10 to 25 per month. 3.2.6 Generally magnitude of fault current may vary between 40% and 100% of the dead short circuit value. However at times the fault current may be much less in case of high impedance faults; bird faults or bond open earth faults shall fall under the category of high impedance earth faults of the order of around 200 Amps fault current. 3.3 Short circuit apparent power of the system

The normal short- circuit apparent power for various system voltages for primary side of traction transformer is as under: -

TABLE NUMBER - 2: Short Circuit Level

Highest system voltage kV

Short circuit apparent power MVA

24 1000 72.5 3500 123 6000 145 10000 245 20000

Fault levels at 110 kV grid sub stations of M/s Tata Power Co, at the respective 110 kV buses are indicated as follow.

TABLE NUMBER- 3 Fault level at the GSS of M/s Tata Power Co.

Grid Substation Three Phase Fault Levels, MVA

Single Phase Fault Levels, MVA

Mahalaxmi 3776 3324 Dharavi 5631 5808 Malad 2922 2747 Carnac 2307 2050 Parel 4048 3539 Salsette 6163 6544 Borivli 4644 4744

A fault on the incoming bus bar of power supply authority can be fed for a period of 500 ms before the protective trippings take place.

580

3.4 Power supplies at traction substation The following power supplies are available at a traction substation.

i.) 110 V (+15 % & -30 %) dc from a battery. ii.) 240V+20% A.C 50 Hz + 5% single phase from a 22/0.24 kV auxiliary transformer.

3.5 OHE impedance

Configuration of OHE in Mumbai are combination of contact wire of size 193 mm2 / 107 mm2 and catenary wire of size 240 mm2 / 322 & 129 mm2 (twin) / 65 mm2. Tenderer shall carry out measurements of the OHE impedance in association with purchaser for the correct setting and operation of the relays within its designed accuracy. The measurement of impedance (R and X values) shall be done by injecting current of order of 800 A in each OHE in each sub-sector i.e. TSS to SSP, SSP to SSP and SSP to SP using suitable 50 Hz, AC voltage source. The likely range of voltage source may be from 100 to 800 Volts. This shall be demonstrated and verified by correct operation during commissioning and proving tests in the field. The existing OHE may be replaced by conventional OHE gradually in a phased manner. 3.6 Booster Transformers

In order to reduce inductive interference on the nearby telecommunication circuits, booster transformers on certain sections of electrified track are installed in series with the 25 kV traction overhead equipment. The primary winding of the booster transformer is connected to the 25 kV overhead equipment and the secondary winding is in series with a return conductor (RC) which is strung close to the 25 kV overhead equipment. Booster transformers of 150 or 100 kVA rating force the traction return current from the rail/earth to flow through the return conductor. The Booster transformers have leakage impedance of about 0.15 ohm each and are spaced about 2.67 kms intervals. The BTs may be installed in a complete sub-sector or in part of a sub-sector.

3.7 Connection of mast to traction rail and traction return. The track circuiting being provided in AC sections of Mumbai area shall be of 2 types.

(a) DC track circuiting (DCTC) (b) Audio Frequency track circuiting (AFTC)

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DCTC is the conventional track circuiting generally available in all conventional system where the traction transformer neutral point is connected to one or both the traction rails near the TSS. The masts are connected to the traction rail and on the track circuit portion only one rail is available for traction returns and in the non-track circuit regions both rails are available for the purpose of traction return currents.

In AFTC type of track circuit Audio Frequencies in the range of 1500 Hz to 10000 Hz are used. The traction return current is ensured as per ACTM provisions and existing practice on Western Railway. Traction mast shall be connected to the designated traction rail.

The Masts in both the cases shall be connected to the traction rail as per the guidelines prevailing / issued for DCTC/AFTC. 3.8 Traction Power Transformer

The primaries of the single phase traction transformers shall be of 220 kV or 132 or 110 kV and the secondary voltage of 27 kV. Transformers of 21.6 MVA will be with 11 to 13 % impedance and / or of 30 MVA with 15 to 17% impedance. The 30 MVA transformers shall be provided with on load tap changer with taps to take care the input voltage variation and maintain the no load voltage of 27 kV on secondary side. On load tap changer can be operated from local and remote through SCADA. At one TSS, transformers of either 21.6 MVA or 30 MVA ratings are provided. Traction transformers of two or three adjacent TSSs may be effectively operated in parallel when the incoming HV supply shall be from same phases and the SPs are bridged, as described in clause 1.1.

The traction transformers shall be designed to carry short time overloads as the traction loads may exceed the rating for short periods.

TABLE NUMBER - 6: Rating of the power transformer

Short time duration Rated secondary current of the Transformer 21.6 MVA 30MVA

Continuous 800 1111 15 Min 1200 1667 5 Min 1600 2222

3.9 Current rating of the OHE. The Current rating of the OHE is generally as follows. The tenderer shall use these values for considering suitable relay and advice to the purchaser on the setting of the relays.

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TABLE NUMBER - 7: Current handling capabilities of the OHE

Type of conductor Current handling limits of the conductor (Amps)

Continuous 15 Minute 65 mm2 Catenary 212 265 240 mm2 Catenary 789 986 322 & 129 mm2 Catenaries, together 1471 1839 107 mm2 Contact 416 520 193 mm2 Contact 629 787 OHE with 65 mm2 catenary and 107mm2 Contact 628 785 OHE with 240 mm2 catenary and 193 mm2 Contact 1536 1920 OHE with 322 mm2 & 129 mm2 catenary & 193 mm2 contact wire

2221 2777

4.0 SERVICE CONDITIONS 4.1 The control panels shall be designed for use in arid and also in humid tropical climate with adverse atmospheric conditions as indicated below, and installed in track side installations:

TABLE NUMBER – 8: Service Conditions 1. Max. ambient temperature. 55 ° C 2. Min. ambient temperature 0 ° C 3. Max. temp attainable by an object exposed to Sun 70° C 4. Max. & Minimum relative humidity 100% & 22% 5. Max. (Basic) wind pressure 150 kg/m2 6. Elevation above the mean sea level max. 1000 m above MSL 7. Average annual rainfall 1750 to 6250 mm. 8. Number of thunderstorm days per annum. 85 days. 9. No. of rainy days per annum 120 days (Max.) 10. Max no of dust storm days/annum 35 days 11. Vibrations Max: 350 micron

Average : 30 – 150 micron Time duration: rapidly varying time duration 15 – 70 ms.

12. Seismic data

Zone Coefficient of Seismic acceleration Importance factor (I)

Zone-III 0.04 2.5 for electrical Equipment & 1.5 for others

13. Pollution level Very heavy, as in IEC 815-1986 & IS 13134-1992

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4.2 The control and relay panel shall be installed at the traction substations, SSPs & SPs which are normally unattended. The panels are situated close to the Railway tracks and hence the Panels are subjected to vibrations due to running trains. 5.0 DESIGN FEATURES 5.1 Constructional Features 5.1.1 The C&R panel shall have modular construction to facilitate expansion and replacement of the C&R panel components. The relays used for protection of HV bus bars, traction transformers, OHE feeder and 25 kV capacitor banks (optional) shall be numeric-processor type with modular construction.

There shall be numeric relay for HV bus bar protection. Transformer protection shall include following protective relays.

a) Numeric type transformer differential protection b) IDMT over current relay for primary as well as for secondary side. The IDMT relay on HV side with an instantaneous over current element. c) Instantaneous earth leakage relay on primary as well as secondary side. d) High speed inter tripping relay. e) Auziliary relays for transformer faults i.e.Buchholz, excessive winding and oil

temperature trip and alarm. f) Reverse power flow relay. g) All relay shall be draw out type.

At least two relays shall comprise of above transformer protections.

Protection of HV incoming lines shall be supplied by the concerned supply authority in a separate panel giving all the necessary control, indication and alarm contacts on the terminal junction inside the panel. However HV bus bar protection and the connections from the protection panel of supply authority to the C&R panel for Railways portion is under scope of this tender. C& R panel shall include the control of all HV breakers including incoming breaker, bus coupling breaker and transformer breakers. All CT and PT termination shall be provided to the HV line protection panel of supply authority installed in the Railway traction substation. Separate 110 V DC and 240 V single phase AC supply shall be extended to the HV line protection panel of supply authority with appropriate rating of MCB.

The distance, WPC, OCR and Delta-I relays used for 25 kV feeder protection shall be of numeric type. The auto reclose scheme for 25 kV feeder circuit shall be realized using intelligent logic based relay of suitable design.

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In case of current operated relays facility shall be provided for automatic shorting of CT terminals when the relays are withdrawn from the respective cases. All the relays shall have flashing LED flags with external reset facility. Contact multiplication for telesignalling to RCC shall be provided wherever required.

Note: - The tenderer is advised to refer Annexure –5 “Material Schedule”

5.1.2 The protection relays shall have facility to record 20 cycles of fault wave form (5 pre fault and 45 post faults both for current as well as the voltage). At a time minimum 8 such wave forms for voltage and currents shall be storable and shall be retrieved through RS 232 serial connection port through a note book laptop computer and or a suitable external printer. Such waveforms shall also be retrievable at RCC through SCADA. Suitable software shall be available to interpret the fault waveform data by the tenderer. The software shall be capable of analyzing the peak, RMS and average values of voltages and currents, D.C. component of currents, harmonic analysis, s and determination of R, X, Z, and φ of the fault voltage, current waveform. The accuracy of measurements shall be 1ms for time, 0.1 KV for voltages and 0.1 KA for currents. 5.1.3 The relay shall be equipped with a serial communication port so as to provide a means of access to the relay menu structure from a remote terminal. The tenderer shall supply the support software for the relay, which shall be used for communicating with the relay and shall allow fault record retrieval, settings/setting groups to be viewed and changed. 5.1.4 The protective relay shall be immune to all even and odd harmonic currents. They shall be tuned for the fundamental frequency or shall work on the principle of fundamental waveform extraction. The relay shall be immune to electrical / electro-magnetic interference. 5.1.5 The relay shall provide date and time stamping up to 1 ms level for each fault. Relay shall have facility for clock synchronization through SCADA or any other similar synchronization facility. 5.1.6 A relay operation counter shall also be provided for each relay with resetting facility.

This shall have facility to put date and time stamp for each tripping. Provision shall be made to store the tripping information in a serial order with a separate data logger. This data shall be retrievable through an external PC. 5.1.7 Suitable transducers or IED shall be employed for converting signals of the CT & PT to desired levels for analog to digital conversion.. The status of switchgears, occurrences of alarm events shall be continuously monitored/ scanned by the concerned relays.

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5.1.8 The protection relays shall be compact in nature. There shall be separate protection relays for H.V bus bar protection, transformer protection, OHE feeder protection and capacitor bank protection (optional). Suitable contact multiplication shall be done as far as possible through software. For this purpose only one set of NO/NC auxiliary contact from each switchgear shall be terminated on C&R panel terminal block. 5.1.9 As the NO/NC signals from the switchgear are used for one of the functions namely alarm, relay operation or in internal logic for interlocking, the burden in some case may be more than what could be met by simple software multiplication. Interposing relays may therefore be used at such places. The over all design however, shall be such as to minimize the wiring. 5.1.10 In case of the feeder protection relay adequate redundancy shall be provided in various elements to ensure that the protection is not disabled and in emergency cases of mal-functioning of a protection unit/ relay, associated circuit breaker is automatically tripped along with corresponding telesignal of the alarm regarding mal-functioning of the protection element. The design shall be fail safe. 5.1.11 The feeder protection modules shall have self-diagnostic feature. Displays for confirming the module healthiness or defects shall be displayed with alarms for speedy trouble shooting by the operator. 5.1.12 The system shall have provision for extension to accommodate the protection for capacitor banks, in addition of OHE circuit breakers of additional lines to cover the future requirements up to 6 tracks normally. 5.1.13 C & R panel are to be of IP 52 to avoid ingress of vermin, insects, rats and dust and suitable for use in tropical humid climate. Protection relays are to be of IP-42 class. 5.1.14 Each feeder protection relay shall have backlit LCD display of appropriate size LCD characters for display of relay status, settings etc. Bright LEDs shall be used for display of power ON conditions and trip indications of the relays. The parameters of the relay shall be settable through a membrane keypad. 5.1.15 As the traction sub-stations are normally unattended, so there shall be a provision for power down mode for the system when the substation is not being manned. In this case all the protection elements shall function as usual but the alarm, annunciation/display and local acknowledgement features will remain out of circuit till the system is activated again. 5.1.16 All the protection relays, D.C. and A.C. supply, equipment in yard, annunciator windows and other peripheral equipment, measuring instruments required for the control panel shall be hard wired to form a control and relay panel. For all the external connections there shall be terminal blocks for terminating the connections. 5.1.17 The panel shall be of the vertical self supporting closed type steel construction, low voltage, back to back duplex corridor type with central roofed in access. The central access

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corridor shall be provided with lockable doors at either end. The control board shall be fabricated from sheet steel of thickness not less than 3.25 mm (10 SWG) for front and rear panels, base frame, door frame, vermin proof fitments and not less than 2 mm (14 SWG) for side panels , roof and doors. The bottom portion of the panel shall be provided with detachable type sheet steel covers (over trench portion) with suitable cable glands to facilitate entries of control cable from trenches to control board, the bottom of central access corridor shall be provided with removable wooden planks of hard wood of adequate thickness to facilitate free movement of working staff. The panel shall be suitable for erection flush with the concrete floor by evenly spaced grouting bolts projecting through the base channels of its frame. The panel shall be made in suitable sections to facilitate easy transport, handling and assembly at site. 5.1.18 All control and supply cables shall be laid in a distribution trench running under the control panel. The cables shall enter the board from the trench through suitable glands. Detailed dimensions of the trench work required will be furnished. Provision shall be made to seal the points of entry of cables to prevent access of rats, insects and lizards into the board. 5.1.19 The sheet steel as well as other steel works shall be properly treated and then an undercoat suitable to serve as base and binder for the finishing coat applied. The exterior and interior surface and the base frame of the panels shall be epoxy powder coated in a shade to be mutually decided later by manufacturer and purchaser.

If any painted surface gets damaged during transit the surface finish shall be restored at site after erection. 5.2 Termination for the purpose of interfacing of C&R panel with SCADA.

5.2.1 Suitable termination for measurands and telesignalling, CT (with shifting link), PT and AT out put for each CT, PT and AT shall be provided in C&R panel. 5.2.2 One set of NO/NC auxiliary contacts for each relay/indicator, CB, interrupter and motor operated isolator shall be suitably wired up and terminated in the C&R panels at TSS for the purpose of telesignalling and issue telecommands for the SCADA. 5.2.3 One set of NO/NC contacts for telesignalling failure condition to be transmitted /reported to SCADA shall be suitably wired up and terminated in C&R panels with identification level at terminals as described in Clause 5.4.4, 5.5.1, 5.6.1, 10.0. 5.2.4 One set of NO/NC auxiliary contacts for telesignalling and to reset each relay after relay has been operated, shall be wired up and terminated in C&R panel. 5.2.5 One set of NO/NC contacts for telesignalling auto reclosure locked out in first cycle and in second cycle and contacts for issue of telecommand for release of locked out. 5.2.6 Over and above, a provision of 30 % spare NO/NC contacts shall be made in the C & R panel wiring which shall be decided at the time of finalization of C & R panel drawings.

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5.2.7 The C&R panel shall have option for setting of relays & retrieving status locally. Appropriate interface equipments shall be provided for exchange of information through SCADA for retrieving the status of relay, waveforms and changing the relay settings by remote through SCADA. 5.3 Control Panel 5.3.1 The scheme of connections at the TSS, SSP and SP showing the circuit breakers, transformers, isolators and interrupters shall be represented by a single line mimic diagram on the control panel. The colour of the bus bar shall be signal red to shade 537 of IS:5 for 220/132/100kV/22KV, golden yellow to shade 356 of IS:5 for 25 kV and black for 240V. The mimic diagram shall be spray painted on the panel with the width of mimic strip of 8 mm. The successful tenderer shall get his designs for layout of equipment and wiring of the control panel approved by RDSO. 5.3.2 Suitable spring loaded push-button switches shall be on the control panels in conjunction with red and green indication LED’s for control and indication of circuit breakers and interrupters. Automatic semaphore relays shall also be incorporated in the mimic diagram to indicate the position of circuit breakers and interrupters. The semaphore relay shall have the feature of disc coming to the neutral position in the event of failure of supply. 5.3.3 A local/remote change-over switch shall be provided for each remote controlled apparatus viz. circuit breaker/interrupter for changing over the control from local to remote and vice versa. The auto-trip circuit operated by the protective relays shall, however, trip the circuit breakers directly irrespective of the position of the change-over switch. 5.3.4 Back lit or bright segmented LED type digital ammeters and voltmeter shall be provided for measuring currents and voltages through the CT, PT’s The accuracy of the displayed parameter shall be 1 Amp and voltage up to 500 Volts. Suitable optocouplers and transient surge suppression / limiter circuits shall be provided to avoid damages to the digital measuring circuits. The meters shall be provided for measuring the following.

i) HV side voltage and current for each of two incoming lines at TSS. ii) Voltage and total load current on 25 kV side each of the two transformers at

TSS. iii) Power factor meter at 25 kV side of each transformer iv) Current of each feeder at TSS v) Voltage at 25 kV bus of SSP vi) Voltage at 25 kV buses of either side of bridging CB at SP vii) Current through bridging CB at SP.

5.3.5 The position of 220 or 132 or 110 kV and 25 kV isolators shall be represented on the mimic diagram by manually operated semaphore switches. The size of the panel shall be large enough to facilitate ease of maintenance. The inside of the panel shall be properly

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illuminated and provided with roof mounted fan to facilitate ease of maintenance. Suitable plug points of 240 V AC for connecting maintenance equipment, test equipment and hand lamps shall be provided inside the C&R panel. The C&R panel may be either duplex or simplex type with sizes 1100x1900x2300 mm or 1100x600x2300 mm. Sizes of the panels are only indicative. The actual size and quantities shall be decided at the time of drawing approval. 5.3.6 Facility shall also be provided on all control panels to verify the availability of 110 V dc supply and continuity of trip circuit for each breaker separately by means of push buttons alongside the control switches and yellow indication LEDs. 5.4 Annunciation 5.4.1 The annunciator shall be provided as a digital LED/LCD type of displays with date and time stamps. Electronic digital sound type alarms of selectable sound shall be provided for the purpose of warning to any staff who may be available locally where an incidence occurs. The LED/LCD shall be of sufficient size and shall be provided at eye level to permit the operator to see and read the occurrence of the incidence clearly. The alarm shall be loud enough be heard from a distance of 20 meters. 5.4.2 Red LEDs shall be provided on the control panel for giving individual visual and audible alarm whenever any of the protective devices or other relays operates. The visual alarm shall be of flasher type which continue to flicker and become stable till, the alarm is accepted. The annunciation LEDs shall be provided on the control panel at the top in suitable number of rows and concerned transformer/circuit-breaker/PT etc. symbol on the mimic diagram, as approved by the purchaser. The alarm accepting, visual resetting and annunciation testing buttons shall be mounted on the control panel at a convenient place & height. The alarm bell shall be mounted inside the control board. 5.4.3 The tenderer shall clearly specify in his offer detailed technical description of the annuniciator clearly bringing out the type of annunciator being provided by him with detailed technical description of the annunciator. 5.4.4 Annunciation shall be arranged for the following fault conditions as are applicable for each circuit. There shall be 30 % spare windows available at the annunciator window to cater for future provisions.

Type I control panel

a) HV breaker trip at the supply authority end ( for each circuit) b) Incoming HV breaker trip at railway TSS (for each circuit) c) Primary transformer breaker trip (for each transformer CB) d) 25 kV transformer breaker trip (for each transformer CB) e) 25 kV feeder breaker trip (for each Feeder CB) f) Transformer Buchholz trip (for each transformer)

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g) Transformer oil temperature trip (for each transformer) h) Transformer winding temperature trip (for each transformer) i) Transformer pressure relief device trip (for each transformer) j) Tap changer pressure relief device trip (for each transformer) k) 25 kV OHE supply /PT fuse fail (for each feeder CB) l) 240 V single phase supply fail (only one No.). m) 220 or 132 or 110 kV line breaker auto trip. n) 220 or 132 or 110 line PT fuse fail o) Communication circuit failed. (If communication based relay is provided) p) Pantoflashover relay bypassed. q) High fault current autorecloser bypassed. r) Main feeder CB stuck (for each feeder CB). s) Tri circuit of CB healthy t) 110 V DC fail supervision u) Low air/gas pressure alarm for each CB v) Trip and lock out on low air/gas pressure for each CB

Type II Control Panel

a) 25 kV line breaker trip for each CB b) 25 kV line PT fuse fail. c) Communication circuit failed. (If communication based relay is provided) d) Pantoflashover relay bypassed. e) High fault current auto recloser bypassed. f) Main feeder CB stuck. g) 25 kV bridging CB trip. h) 25 kV bridging CB close. i) Tri circuit of CB healthy j) 110 V DC fail supervision k) Low air/gas pressure alarm for each CB l) Trip and lock out on low air/gas pressure for each CB Type III Control Panel

a) 25 kV line breaker trip for each CB b) 25 kV line PT fuse fail. c) Communication circuit failed.(If communication based relay is provided) d) Pantoflashover relay bypassed. e) High fault current auto recloser bypassed. f) Main feeder CB stuck. g) Trip circuit of CB healthy h) 110 V DC fail supervision i) Low air/gas pressure alarm for each CB

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j) Trip and lock out on low air/gas pressure for each CB

Type IV Control Panel This shall be tailor made as per the specific requirement of the purchaser. The annunciation to be brought out shall be discussed and decided mutually between the purchaser and the tenderer. 5.4.5 For monitoring the OHE supply or 240 V supply, suitable relays operated off the OHE PT or 240 V supply respectively shall be provided in the control panel by the successful tenderer. A push - button, in series with each of these supply monitoring circuits, shall be provided by the side of the corresponding supply fail indication LED to test the healthiness of the monitoring and annunciation circuit. 5.4.6 A hooter or high audio level alarm for detecting the low D.C. or High D.C. voltages shall be provided. The alarm shall sound in case the D.C. control voltage goes beyond the limits as specified in this specification. (High or low) 5.5 DC supply supervision and annunciation 5.5.1 A provision shall be made for annunciation and supervision of 110 V d.c. supply to various control and alarm and indication circuits. 110 V d.c. supply to control and relay panel is normally made available from 110V battery chargers/batteries through distribution panel provided in the control room, in six separate circuits as under:

Type – I Control panel

a) Control circuit for HV incoming line and bus coupling breaker. b) Control circuit for H.V. and L.V. breakers of traction transformer - 1. c) Control circuit for H.V and L.V. breakers of traction transformer - 2. d) Control circuit for 25 kV feeder breakers.(One control circuit for two track) e) A common circuit for alarm and indication purposes. f) D.C. control voltage from battery low.

Type – II & III Control panel

a) Control circuit for 25 kV feeder breakers. b) A common circuit for alarm and indication purposes. c) D.C. control voltage from battery low. Type – IV Control panel (The design & specification for this type of control panels shall be as mutually

agreed to between the Purchaser and the tenderer)

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5.5.2 Provision for supervision of d.c. supply to each of the above circuits shall be ensured. On failure of d.c. supply to any circuit, a yellow LED (provided individually for each of the circuits) and horn / siren / electronic sound , operating both from 240 V A.C. single phase supply and separate battery supply (tenderer’s scope) shall come up. The side of the corresponding D.C. fail indication LED shall provide a push button, in series with each supervision circuit, in order to test the healthiness of the supervision and annunciation circuit. In addition, a common miniature type push button for the cancellation of horn shall also be provided. 5.5.3 The control/common circuits mentioned in Clause-5.5.1 above, being common for all the panels, are segregated suitably at the control panel for each panel through links etc. so that D.C. supply is available to other panels when any one is taken out of service for maintenance purpose. 5.5.4 Low control voltage alarm

A definite time under voltage relay shall be provided to detect the dropping of the D.C. control voltage below the level as specified in this specification. Alarm / Hooter shall be sounded if the low voltage condition persists for more than 10 sec. 5.6 Trip circuit supervision 5.6.1 The continuity and the availability of DC supply to the trip circuit of each circuit breaker shall be monitored independently by an auxiliary relay connected in series with the trip coil of the breaker. The current taken by the auxiliary relay shall not exceed 10 mA. Whenever the auxiliary relay de-energizes (while the breaker is in the closed position) either due to discontinuity in the trip circuit or d.c. supply failure, a yellow LED (provided individually to the trip circuit of each breaker) and horn, both operated off 240 V , single phase supply, shall come up. The side of the corresponding trip-circuit fail indication LED to test the healthiness of the supervision and annunciation circuit shall provide a push button, in series with each of these auxiliary relays. 5.6.2 Since the substation is un-attended, necessary cut-off switches shall be provided on each control panel for disconnection of the audio-visual alarm and annunciation and indication circuits to avoid un-necessary drainage of the battery. 5.7 Indication LED’s 5.7.1 Low consumption, extra bright, 5 mm dia, light emitting diodes (LEDs) shall be used wherever required. The LEDs shall be suitably wired to glow off at 110 V d.c. supply. LEDs shall be housed in suitable metallic holders with glazed/polished surface to act as reflector. The holders shall be screwed to the panel from inside. 5.7.2 The following colour scheme shall be adopted for indication LED’s.

TABLE NUMBER – 10 Colour scheme for wiring S.No Signal for Colour of light

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1. Circuit breaker closed Red 2. Circuit breaker open Green 3. Trip circuit healthy *Yellow 4. Circuit Breaker auto trip *Amber 5. 110 V D.C. fail supervision *Amber 6. Line potential *Red 7. Blower fan working *Blue

* These LED’s shall normally remain extinguished and shall light on

occurrence of the alarm / fault. 5.8 Test terminal blocks 5.8.1 Suitable test blocks shall be mounted conveniently inside the control panel so as to be easily accessible. The current rating of the contact shall be 10 A continuous and 150 A for at least one second at 240 V a.c. or 110 V d.c. The current terminals shall be provided with short circuiting links or other suitable devices:

a) To short circuit the current transformer leads before interrupting the normal circuit for injection from external source for testing (applicable for secondary injection tests of relays).

b) To complete the current transformer circuit through a testing instrument in which

case the testing instrument shall be connected to the current terminals and the intermediate link opened out (applicable for checking indicating instruments with sub-standard meters at site).

5.8.2 The potential testing terminals shall be preferably housed in narrow recesses of the moulded insulation block to prevent accidental short circuits. The arrangement of the terminals shall be made such that either portable type energy and maximum demand meters, or trivector meters with printo-maxigraph for recording kW, kVA and kVAR can be connected when required.

5.8.3 Vertical or horizontal pillar stack type terminal blocks suitable for 1100 V service and not less than 30 A rating shall be provided for terminating outgoing ends of control panel wiring and the corresponding incoming tail ends of the control cables. Provision shall be made on each pillar for holding 20% extra connections. The terminal blocks have individual identification markings which shall be either engraved or made indelible by any other means. Pillars of terminal blocks meant for connections of incoming control and indication cables shall be specially provided with identification labels indicating function(s) of each terminal block.

5.8.4 The terminals on the terminal blocks shall be of stud type suitable for terminating the ends of control wiring and outgoing cable ends through crimped terminal spade/lugs, which shall be securely tightened with nuts and spring washers. Suitable shrouds of unbreakable transparent material shall also be provided on each terminal block.

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5.8.5 Terminal blocks connected to potential circuits and current circuits shall not be placed adjacent to each other in a pillar. Where such segregation is not convenient due to any reason, a dummy spacer of insulating material of adequate thickness or a space terminal block shall be provided in between two such circuits. 5.9 Wiring of the C&R Panel 5.9.1 All panel wiring shall be done with switch board type 1100 V grade PVC insulated single core, tinned annealed stranded copper conductors for service in extremely tropical climate. The PVC wires shall conform to latest version/revision of IS:694 and duly tested for flammability test as per IS:10810 (Part 53)-1984. The wiring shall also not be prone to attack by vermin, i.e. mice, white ants, cockroaches etc. 5.9.2 The size of wires in the meter and relay circuits connected to the current transformers shall not be less than 4 mm2 copper and in potential and other circuits not less than 2.5 mm2 copper. The wires shall be stranded, composed of strands of not less than 0.91 mm (20 SWG). 5.9.3 The numbering and scheme of wiring for various circuits in the control and relay panel shall be in accordance with latest version of IS: 375. The following colour scheme shall be adopted for the wiring in order to facilitate identification of circuits:

TABLE NUMBER – 11 Colour schemes for wiring

S.No Circuit Colour of wire 1. 220 or 132 or 110 kV current

transformer circuit. Blue

2. 220 or 132 or 110 kV PT circuit. White 3. 25 kV potential transformer circuit Yellow 4. 25 kV current transformer circuit. Violet 5. 240 V A.C. auxiliary phase

neutral Red Black

6. DC control circuits Grey 7. Earth circuit Green

PVC sleeves of colours, red for trip circuit, blue for indication circuit, yellow for

alarm circuit, green for relay and other inter connections to be provided. 5.9.4 A suitable plaque of durable material and description giving the colour scheme of wiring shall be provided inside the control board to facilitate quick identification of circuits for maintenance purpose. 5.9.5 All potential bus wiring, D.C control supply bus wiring and other such other wiring which runs from panel to panel within the control panel shall be suitable supported and clipped to the frame work. The wiring for interconnection between control and relay panels

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shall be fixed under the roof of the corridor. All wiring shall be neatly bunched with PVC tape or laced by thread. 5.9.6 Where a bunch of wire is clamped by metal clips, the wires shall be taped together by one or two layers of PVC tape to protect them against mechanical injury. Wiring connected to the space heaters in the panels shall be provided with porcelain beaded insulation for a short distance from the heater terminals and heat resistant bushes of insulating materials shall be provided at the terminal housing outlets. No joints shall be permitted in the wiring. 5.9.7 The terminal ends of all wires shall be provided with numbered interlock type ferrules, which are of PVC, or other durable material with marking either engraved or punched so as to be indelible. The ferrules shall be of white colour with black lettering thereon. However, for trip circuits ferrules of red colour shall be used. At a point of inter-section where a change of number is necessary, duplicate ferrules shall be provided and marked with proper numbers. 5.9.8 Ends of all wires shall be provided with terminal spades (tinned) which shall be crimped to the wires. At terminal connections, washers shall be interposed between wire terminals and holding nuts. The connection studs project at least 3 mm from the lock-nut surface. Wire ends so connected at the terminal studs that no terminal ferrule gets masked due to the succeeding connections. The wire ends shall be suitably bent to meet the terminal stud at right angles with the stud axis; skew connections shall not be permitted. 5.10 Fuses and Links 5.10.1 HRC fuses of adequate current rating shall be provided in all potential circuits. Fuse bases and carriers shall be mounted in the interior of the control board and at easily accessible places. The fuse rating and the identification number, as assigned in the schematic diagram shall be indicated on the fuse carriers. Suitable labels with engraved markings indicating the rating, identification number and the circuit in which used, shall also be provided below the fuse bases. 5.10.2 The links provided in the circuits either on negative/neutral side or for branching purposes, shall also be similar to fuses mentioned above, except that these shall be provided with tinned copper strip of suitable size in place of HRC fuse. The link identification number as assigned in the schematic diagram shall be indicated on the link carrier. The link base shall also be identified in the similar manner as the fuse base mentioned in Clause 5.9.1. 5.11 Space Heaters & Control panel lighting 5.11.1 Suitable space heaters to operate off 240 V single-phase ac supply with `ON’ switches shall be provided inside the control board to prevent condensation of moisture in humid weather.

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5.11.2 The interior of control panel enclosure shall be adequately lighted by incandescent lamps/ florescent tube light connected to 240 V single phase ac supply. The central corridor shall be illuminated by a lamp controlled by the door switches provided on the doors on either side of the corridor. Each section of the control and relay panel shall also be illuminated, controlled by separate switches. 5.11.3 Two sets, one each for relay panels and control panels, of 5 Amps, single phase, 3 pin plug sockets with switches shall be provided inside the control board at convenient points for use of portable lamps. 5.12 Earthing 5.12.1 All current free metallic bodies of equipments/ relays etc. on the control board shall be earthed properly. Main earth circuit shall be of 25 x 3 mm tinned copper strip and individual connections of equipment/relays with main earth circuit shall be by means of 2.64 mm (12 SWG) tinned annealed copper bare conductor/strips, using tinned copper spade terminals/lugs. Some times as an alternate, PVC insulated stranded tinned copper wire of size equivalent to 2.64 mm (12 SWG) shall also be provided. Joints shall be avoided as far as possible. 5.12.2 In order to facilitate the earthing of secondaries of CTs and PTs inside the control board, suitable earth links of adequate size made of tinned copper/brass shall be provided inside the control board at the appropriate points. 5.12.3 Multiple earthing of current/potential transformer circuits shall be avoided. Main earth connection for each panel shall be brought out to two terminals for connection to the general earthing system. 5.13 Name plate and Identification labels 5.13.1 All relays, instruments and other electrical devices mounted on the board shall have name plates with rating data, serial number and manufacturer’s name. 5.13.2 Identification labels of size 65 x 13 mm bearing identification marks indicating functions of respective equipments shall be provided on the exterior of control and relay panels under all the relays, instruments and test blocks etc. Similar labels shall also be provided under the switches where necessary. 5.13.3 Identification labels of size 25 x 25 mm bearing identification marks indicating numbering of respective equipments shall be provided beside the semaphores, power transformer and auxiliary transformer positions on control panels. The control and local/remote selector toggle switches shall be provided with suitable labels duly inserted in their pockets available for the purpose. The scheme of numbering of various equipments in traction substations shall be supplied by the purchaser.

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5.13.4 All push buttons on the control panel shall have suitable inscription on their collars indicating the functions of each push button. Where such collars are not available, separate indicating labels of PVC sheet of suitable width and length not more than the overall outside dimensions of the push buttons shall be provided. Similarly, the function of each indication and annunciation LED shall be indicated by a label of elegant design and appropriate size shall also be provided alongside/along with the concerned LED holders. The inscription shall clearly convey the function of each indication LED. 5.13.5 Plastic plates about 50 mm wide, bearing suitable captions to identify the transformer bay and corresponding outgoing 25 kV feeder, shall be provided on the top of each relay and control panel. 5.13.6 All the identification labels on the exterior of control and relay panels shall be secured with the help of chromium plated metallic screws. 5.13.7 Identification labels shall also be provided in the interior of the control panel. For such of the equipments and fittings, which are exclusively mounted inside the control panel, the labels of suitable size indicating function of respective equipment shall be provided. Whereas the labels inside the control board for the equipments mounted flush/semi-flush outside the control and relay panels, bear reference index code corresponding to the schematic diagrams. 5.13.8 The labels inside the panels shall be secured with the help of adhesive of good quality (wherever necessary). The labels in the interior of the board under the equipments/relays shall be so provided that they are not obscured due to bunches of wire runs and any other obstructions. Painting of inscriptions shall not be permitted. 5.13.9 All inscriptions on the labels to be fixed on the control and relay panels shall be made on the PVC sheet strip of black background with white engraved letters/figures. However, the labels to be fixed inside the panels shall be either of engraved lettering or of aluminium anodized screen printed type. 5.13.10 The lettering for inscriptions on the labels shall be generally of the following sizes:

TABLE NUMBER –12 Label Sizes

S. No.

Label description Size of label Height of letters/figures

1. Main labels to be provided on the top Panels.

50 mm x length to suit

15 mm (two rows)

2. Circuit labels to be provided at the bottom of the panels

13 mm x 65 mm 5 mm (single row)

3. Function label under the equipments 13 mm x 65 mm 4 mm 4. Push button and indication LED labels - 4 mm (single

row) 3mm(double row)

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5. Equipment numbering labels. 25mm x 25 mm 7 mm 6. Control & selector switch labels - 7 mm 7. Labels under fuses and links. 25mm x 25 mm 3 mm 8. Reference labels(Interior of panel) 25mm x 15 mm 5 mm 9. Terminal block pillar numbering labels 10mm x 15mm 5 mm 10.Terminal numbers on terminal blocks - 3 mm 11.Function inscriptions on terminal blocks - 3 mm

Note: - However, in case of space limitations, the manufacturer may adopt suitable label dimensions without affecting the legibility and aesthetic appearance of the panel. Any other label not covered above shall be of matching size.

6.0 SCHEME OF PROTECTION

The scheme of protection provided at each of the traction substations and SSP/SPs shall comprise of the following systems: a) Incoming 220 or 132 or 110 kV HV line protection shall be under the scope of

supply authority. However HV bus bar protection shall be covered under this specification and shall be under scope of the tenderer. Refer clause no. 2.2 (i) and 5.1.1.

b) Protection of the 220 or 132 or 110 /25 kV transformer installed at the traction substation.

c) Protection of the 25 kV traction overhead equipment. d) Protection of capacitor bank equipment (if asked for by the purchaser in the

tender).

The relays to be provided shall have the following functional requirements.

i) They shall be immune to distorted power frequency waveforms caused by the harmonics, phase shifts and transient faults.

ii) The relays shall be insensitive to power swings, permissible overload and transient

condition including magnetizing inrush current of locomotive transformers and shall be suitably designed to compensate the effect of fault are resistance.

iii) All the relays except reverse power flow relay shall be immune to reverse power flow in case of regenerative current going back into the grid.

iv) They shall of standard design and be fail safe in design. Any failure of the relay

shall either cause taking over of the functions of the relay by another relay or cause it to fail in a manner so that the safety of the 25 kV distribution is not affected.

v) The relays with communication features shall have necessary interface equipments

and follow the standard communication protocol of IEC 60870-5-103.

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vi) The relays shall be suitable for operation from the 220 or 132 or 110 and 25 kV current transformer and potential transformer to the following particulars:

TABLE NUMBER -13 Ratings of CT and PT on 25 kV side S.No Description CT PT 1. Rated system voltage 25 kV rising up to 30 kV 2. Rated transformation

ratio 3000-1500/5A 25000/110V

3. No. of cores Two Two winding 4. Core-1 Core-2 5. Rated burden - - 100 VA

6. Accuracy class PS PS 0.2 as per IS: 3156 (part II) & 3P as per IS: 3156 (part

III)-1992 * Two cores on 25 kV CTs are provided considering one core for differential bus bar protection and other core for balance protection relays viz. DP relay, OCR.

TABLE NUMBER -14 Ratings of PT on 220 or 132 or 110 kV side

S.No Description PT 1 Rated system voltage 220 132 110 2 Highest system voltage 245 145 123

3 Rated transformation ratio

220kV/110V 132kV/110 V 110 kV/110V

4 No. of windings Winding 1 Winding 2 5 Rated burden 100 VA 200 VA 6 Accuracy class 0.2 3P

TABLE NUMBER -15 Ratings of CT on 220 or 132 or 110 kV side

S.No Description CT 1 Rated system voltage 220 132 110 2 Highest system voltage 245 145 -

3 Rated transformation ratio

300-200-100/5 600-400-200/5 1200-800-400/5

No. of cores four cores Core 3

Protection Core 2

Metering Core 1&4 Protection

4 Rated burden 40 VA 40 VA -

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5 Accuracy class 5P20 0.2 PS

vii) The relays shall conform to accuracy class 10 as per IS: 3231-1965. However

distance relays shall be of class 5. viii) The relay relays shall be provided with dust tight covers ix) The current coils shall be rated for a continuous current of 5 Amps for relays on

type-I, II, III & IV panels. The voltage coil shall be rated for 110V. The contacts of the relays shall be silver plated. The current coils shall be capable of withstanding 20% overload for 8 hours.

x) The relays shall be designed for continuous service voltage of 110V d.c. and shall be capable of satisfactory operation up to at least +15 %, - 30% fluctuation in voltage.

xi) The contact of the relay shall be of silver or gold plated. The rating of output contacts of the protective relays shall be adequate to operate the associated output relays.

xii) The relays shall have nameplates with rating data, serial no. and manufacturer’s name marked on them. The metal case shall be provided with separate earthing terminals.

For protection of incoming HV line, transformer, substation equipment’s, feeders and capacitor bank, the following relays shall be provided on a miniaturized control panels housed in the masonry cubicle at the traction substation, SSP or the SP. 6.1 HV protection

a) Incoming HV line protection ( to be provided by supply authority)

1. Fiber optic line differential protection 2. Directional over current relay 3. LBBU relay (LBB- breaker failure relay) 4. Under voltage relay with time relay. 5. Over voltage relay with time relay.

b) HV bus bar protection to be provided by tenderer Differential biased bus bar protections relay 6.2 Transformer Protection i) Numeric Percentage biased differential relay ii) IDMT over-current relays for the primary as well as for the secondary (25 KV)

side. The IDMT relay on the HV side is provided with an instantaneous over-current element also.

iii) Instantaneous earth leakage relays on the primary side as well as on the secondary (25 KV) side.

iv) High speed inter-tripping relay. v) Auxiliary relays for transformer faults i.e. Bucholz, excessive winding and oil

temperature trip and alarm and low oil level alarm.

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vi) Reverse power flow relay. 6.3 25 kV Bus and Over head equipment protection.

The relays mentioned below are the main relays only. Other minor relays and auxiliary relays required for functioning of the completed protection scheme have not been indicated.

6.3.1 25 kV Bus and Feeder Protection at TSS a) High impedance type differential protection relay for bus bar b) Feeder protection

The following protections shall be provided– i) Directional numerical distance protection relay with 3 zones and polygonal

characteristics. ii) wrong phase coupling iii) Directional definite time over current relay with instantaneous over current

element. iv) PT fuse failure v) Intelligent logic based auto recloser. vi) Vectorial Delta-I Relay for detecting high impedance faults. vii) Pantoflashover prevention & signalling relay (optional)

6.3.2 For SSPs

The following protection shall be provided for each circuit breaker– i) Directional Numerical distance protection relay with 3 zones and polygonal

characteristics. ii) Directional definite time over current relay. iii) High impedance type differential protection relay for bus bar iv) Panto flashover prevention & signalling relay (optional). v) Intelligent Logic based auto reclosures. vi) PT fuse failure.

6.3.3 For SPs

The following protection shall be provided for each circuit breaker–

i) Directional Numerical distance protection relay with 3 zones and polygonal characteristics.

ii) Directional definite time over current relay. iii) High impedance type differential protection relay for bus bar iv) Over current protection relay for bridging CB v) Under voltage protection relay for bridging CB

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vi) Panto flashover prevention & signalling relay. vii) Intelligent Logic based auto reclosures.

viii) PT fuse failure 6.3.4 Shunt Capacitor Bank Protection.

(Optional only if demanded specifically by the purchaser) The protection system for capacitor bank shall be as per the relevant RDSO specifications of capacitor bank viz. ETI/PSI/67 (11/96) with A&C slip no. 1 to 7- for shunt capacitor bank or TI/SPC/PSI/THYCAP/0030- for thyristor switched capacitor bank or any other latest RDSO specifications.

6.4 Synchrocheck relay For the TSSs which shall be operated in parallel, synchrocheck relays shall be provided on transformer LV side breakers at TSS and at bridging CBs at SP. The relay contacts shall be provided in the closing circuit of these CBs to ensure proper synchronization between two sources. The relay shall have separate adjustable settings for voltage magnitude (having range of 0-10% in steps of 0.5%) and phase angle (having range of 0-5° in steps of 0.5°). DETAILS OF PROTECTION SCHEME FOR HV INCOMING LINES 7.1 Details of incoming HV line protection including following shall be provided by

supply authority.

1. Fiber optic line differential protection 2. Directional over current relay 3. LBBU relay (LBB- breaker failure relay) 4. Under voltage relay with time relay. 5. Over voltage relay with time relay.

7.2 Differential biased bus bar protections relay

7.2.1 Protection against bus faults shall be provided by means of a sensitive differential low impedance type protection relay. The relay shall be of the high speed type and operates in less than 40 milli-seconds for 2 times the rated current and in less than 15ms at currents of 10 times the set value. The following features shall be incorporated in the relay. 7.2.2 The current setting of the relay shall be adjustable in appropriate steps. The % error in operating current shall not exceed + 5 %.

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7.2.3 The relay shall have overload current handling capabilities up to 2 times the set current permanently & 40 times the set current for one second. 7.2.4 The relay shall not operate for maximum through fault current. 7.2.5 Three number out put trip contacts shall be provided on the relay to trip the desired CBs simultaneously. 8.0 DETAILS OF PROTECTION SCHEME FOR 220/25kV, 132/25 kV, 100/25kV, 22/25 kV TRANSFORMER 8.1 Differential Protection 8.1.1 Protection against internal faults shall be provided by means of a sensitive single-pole numerical differential protection relay. The relay shall be of the high speed type and operates in less than 40 milli-seconds for 2 times the rated differential setting current and in less than 15ms at currents of 10 times the set value. The following features shall be incorporated in the relay: 8.1.2 There shall be no necessity for changing the setting of the relay when the transformer tap is changed. The traction power transformer is provided with taps from +10% to –15% in steps of 1.67% each. 8.1.3 The relay shall not operate for maximum through fault current. Necessary harmonic restraining features shall be incorporated to prevent operation due to in-rush of magnetization current when the transformer is charged either from the primary or the secondary side. The relay shall have second harmonic magnetic inrush restraint feature in order to prevent unwanted tripping. The relay shall be insensitive to inrush currents up to 5 times the differential setting of the relay. Also the relay shall be blocked for operation in case second harmonics exceed a predetermined set limit. The limit of blocking the relay shall be decided between the purchaser & tenderer after carrying out measurements as in 13.1. To start with, the relay shall be blocked for operation in case 2nd harmonic current exceeds 15 % of the fundamental current. 8.1.4 The current setting of the relay shall be adjustable, preferably between the range of 20-50% in suitable steps. Percentage error of operating current shall not exceed + 5 %. 8.1.5 Adjustable bias setting shall also be provided. The bias at minimum operating current setting shall be 15% to 50% in 6 steps for this relay to suit the tapping range of the traction transformer and other design considerations. 8.1.6 The relay shall be connected to bushing type current transformers provided in the bushings of 220/25 kV, 132/25 kV, 110/25 kV, 22/25 kV transformers. However it may be optional to connect the relay to the separate current transformers (PS class core) provided on the HV & LV sides of transformers. This way bus bar, CB and other equipments shall be covered under the differential protection. However, interposing current transformers of

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suitable ratio and rating with matching characteristics of knee point voltage, excitation current etc. are provided with the differential relay in order to boost up the bushing CTs secondary current, at full load, to a value equal to relay rated current. Magnetization and ratio error curves for the current transformers shall be supplied by the purchaser to enable the tenderer to match the characteristics of the relays and interposing CTs with those of the current transformers. The interposing CT shall be within the scope of supply by the tenderer. The tenderer can also supply a software based integral CT ration compensation instead of the conventional interposing CT. 8.1.7 The relay shall have overload current handling capabilities up to 2 times the set current permanently & 40 times the set current for one second.

8.2 Earth-Leakage protection.

Back-up protection for internal earth faults within the transformer shall be provided by means of a sensitive, high speed, earth-leakage instantaneous relay of very low pick up current. Such relays shall be provided separately on both the primary and secondary sides of the transformer. Both on the primary and the secondary sides the relays shall be connected to separately mounted current transformers. The current setting for the relay shall be adjustable between 10% and 80% of 5 Amps in equal step at 5%. The relay shall be of T 10 class with operating time not exceeding 20 ms for currents of 5 times the relay settings. The relay may be operated on voltage principle with suitable voltage setting based on fault current levels of transformers.

8.3 Over current protection Protection against over-current in the transformer shall be provided by means of single-pole, non-directional over-current relay with inverse definite minimum time lag (IDMT) characteristics both on the primary and the secondary sides of the transformer. Further, an additional instantaneous over-current relay shall be provided on the primary side. On the primary side the over-current relay shall be connected to separately mounted current transformers. On the 25 kV side the over-current relay shall be provided only on the live (unearthed) leg of the power transformer through a separately mounted current transformer. The over-current relay on the secondary side shall serve as back-up protection against faults in the 25 kV overhead equipment and also against bus faults etc. The over-current relays on the primary side shall serve as back up to the over-current relay on the 25 kV side as well as back-up to differential and earth leakage relays against heavy faults. Proper discrimination shall be maintained in the operation of these two sets of over-current relays. The tenderer shall develop relay setting guidelines with supporting calculations and submit to RDSO for scrutiny and approval. The setting on these relays shall be adjustable as under:

TABLE NUMBER 16 Setting range of IDMT Relay

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Sl. No.

Item Current Setting Time Multiplier setting

IDMT over-current on primary side.

80% to 320% as per IDMT curve 3-sec at 10 Ir

0.1 to 1

Instantaneous over current on primary side

400% to 1600% of IDMT setting

-

IDMT over current on secondary side.

80% to 320% as per IDMT curve 3-sec at 10 Ir

0.1 to 1

The instantaneous relays shall be of T 10 class with operating time not exceeding 20

milli-seconds at the set. 8.4 Intertripping Relay

The differential relay and earth leakage relay both on the primary and 25 kV sides as also the over-current relays on primary side shall cause inter-tripping of the 220 or 132 or 110 and the 25 kV circuit breakers associated with the transformer. The inter-tripping of the associated transformer circuit breakers on Primary and 25 kV side shall also be effected due to other faults in the transformer, namely Buchholz trip, excessive winding temperature and excessive oil temperature trip.

The IDMT over-current relay on the secondary side shall, however, trip the

respective circuit breaker on 25 kV side only. The inter-tripping of associated transformer circuit breakers envisaged above shall be effected through a high speed tripping relay with manual reset contacts. Such inter-tripping relay shall lock out the closing of circuit breakers from all modes of closing commands viz. Remote control, local control at the panel and also at the circuit breaker mechanism, until the inter-trip relay or the lock out relay (if provided separately), is reset manually

Operating time inter trip relay shall not exceed 20 ms. 8.5 Other Protective devices.

The transformers as supplied by the purchaser shall be fitted with the following warning and protective devices:

i) Low oil level alarm. ii) Buchholz relay with alarm and trip contacts. iii) Oil temperature indicator with alarm and trip contacts. iv) Winding temperature indicator with alarm and trip contacts. v) Pressure relief device with alarm and trip contacts.

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These contacts shall be wired up to a weather-proof terminal box mounted on the transformer by the transformer manufacturer. The connections shall be extended to the alarm and trip circuits as well as to annunciation scheme provided on the control panel. 9.0 DETAILS OF SCHEME OF PROTECTION FOR 25 kV OVERHEAD EQUIPMENT a) The substation equipment as well as the overhead equipment is protected against short circuits and over-loads by means of feeder circuit breakers. The detailed feeding arrangement has been indicated in the annexure 6 and the protection schemes at TSS, SSP and SP are indicated in annexure 7 (3 sheets). b) The normal zone of feed of a substation to a neutral section varies from 6.5 to 25 Km., The spacing between the adjacent TSS, SP & SSP is of the order of around 1-5 km. Under emergency feed conditions, the zone shall be extended up to the next substation by closing the bridging CB at the neutral section and will be about double the zone of normal feed. Over current or plain impedance relays which operate below a certain impedance level and which function independently on the phase angle between voltage and current, will be unable to discriminate such faults. Therefore, a relay working on the principle of discrimination of the argument of the impedance is required. The protection shall also have directional elements to distinguish the fault in a particular zone. c) The OHE protection scheme shall fulfill the following functions-

i) To detect all short circuits over the affected zone of overhead equipment and to

open the circuit breakers of the affected zone only. The healthy section shall remain unaffected.

ii) In case a sub-sector has been isolated due to a fault, then the balance healthy section left shall continue to have the effective protection operational.

iii) To operate with minimum delay in opening the circuit breaker.

iv) To refrain from operation at the maximum working current, i.e. to discriminate between the maximum load currents and short circuit currents even though the magnitude of the former (maximum working current) is at times more than the latter (short circuit current), especially when the faults are remote from the substation.

v) To detect and isolate faults on the OHE caused by accidental coupling of two different phases from adjacent substations.

vi) To prevent flash-over at the insulated overlaps in front of the TSS, SSP overlaps in the event of one of the wires of the OHE is switched OFF on transient faults and a locomotive / EMU pantograph bridges the live and the unearthed OHE. Relay shall also be able to give a signalling command as per user’s requirement

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in case a communication link between adjacent TSS/SSP is not provided by the purchaser. The purchaser shall specify his detailed requirement to this extent while tendering.

vii) To provide high speed auto-reclosing of the feeder circuit breaker after a preset

time interval and to lock out if the fault reappears within a predetermined time period. The autorecloser shall have built in logic / intelligence as described in the subsequent para.

viii) To provide a suitable protection device to detect and trip the feeder Circuit

Breaker in the event of High impedance Earth Faults.

ix) The protection shall be immune to variations in arc resistance of the faults and the excitation current of the traction locomotive and power transformers. To avoid transient tripping due to high starting currents of EMUs/Locos, the relay operation shall be blocked in case 2nd Harmonics exceed 15 percent or a value as mutually decided between the purchaser and tenderer.

x) To be immune to the regenerative currents. The protection should not act in case

the regenerative currents are fed back into the system. xi) The main feeder protective relays like directional numerical distance protection

relay with 3 zones and polygonal characteristics, intelligent logic base auto reclosure etc. shall have necessary interface equipments to ensure the working of the relay over communication channel if the purchaser so decide at a later date. The details of protective system shall therefore be as follows: -

9.1 Directional Numerical distance protection relay with 3 zones and polygonal characteristics 9.1.1 The requirements are – a) Relays to be single phase version b) Impedance characteristic shall cater for –

i) Load encroachment ii) Sudden loads due to locomotives start up. iii) Short line sections iv) High resistance fault currents very close to load currents

9.1.2 The relay shall have the following essential features a) Relay shall have polygonal characteristics, which includes parallelogram characteristics. b) The relay shall have 3 distance zones. Each zone can be set individually for its R

and X values. Each of the zones can be set in forward or reverse or non directional zone. Setting of relays for each zone shall be done depending on the measurements as per clause 13.1. The relay shall trip instantaneously in zone-I and with present

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delay in zone-II and III. It shall be possible to set the delay in the range from 50 to 2000 ms in steps of 10 ms.

c) Zone-I extension. d) Zone 2 and 3 with train start-up detection –

In case of train start-up loads, zone II, III may pick up. The relay should detect and avoid tripping.

e) Back up Over Current protection f) A “Switch onto fault” feature (SOTF) shall be provided in the relay to provide high

speed tripping (of the order of one cycle) in case the breaker is closed onto an existing fault on the line.

g) Over and under voltage protection with voltage supervision along with time delay (optional).

h) Auto reclosing. i) The errors in the relay shall not be more than + 5% for R, X, V, I and the measured

Z value j) Since the OHE parameters R & X shall be varying through out the section and also

shall be changing during the various phases of the work execution, the relay shall be capable of changing the R & X values to all possible combinations of the OHE. The relay shall also be capable of changing the fault angle over a range of 50 to 85 degrees in steps of 5+1 degrees.

k) The accuracy of the relay shall be + 5 % including for voltage input to the relay from 125 volts down to 0.5 Volts, the frequency variations of 47 to 52 Hz and the ambient temperature variation over the range + 5 OC to + 50 OC.

l) The relat shall give a command to the auto reclosure to bypass it in the event of a fault in the 2nd zone or beyond.

m) The relay shall have facility to record and store fault waveforms for all CB tripping cases with date and time stamping. 10 such waveforms shall be store as brought out in details in the para 5 .1.2 above.

n) The impedance reach of each zone of protection shall be manually adjustable over a range of 0.04 ohm to 50 ohm. For time delayed zones, it shall be possible to independently vary the zone time settings in a range of 50 ms to 2000 ms. The timer accuracy shall be + 5 % of setting.

o) The relay shall also be capable of changing the fault angle over a range of 50 to 85 degrees in steps of 1 degree (with accuracy of +1 %)

p) The relay shall continuously monitor the status of the feeder CB at TSS. In case the feeder CB is not tripped after a preset time interval after initiating the trip command then another trip command shall be given to the transformer CB to trip. Suitable alarm confirming the failure of the concerned CB shall be displayed.

q) The relay shall continuously monitor the status of the feeder CB at SSP/SP. In case the feeder CB is not tripped after a preset time interval after initiating the trip command in zone-I then trip command shall be given to all the CBs connected to the concerned bus of SSP/SP to trip. Suitable alarm confirming the failure of the concerned CB shall be displayed

r) The PT voltage is continuously monitored by the relay in case of blowing out of the PT fuse (conditions when PT is low but the current is less than the set current) an alarm

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shall be given out after suitable settable time delay. In case the PT voltage is low and the current is more than the set current the relay shall trip the feeder CB.

s) The relay shall have feature of fault locator with an accuracy of +2 %. Necessary interface equipments are to be provided to send the fault location in km. from relay location to remote control centre through SCADA.

t) The relay shall be blocked for operation in case second harmonics exceed a predetermined set limit. The limit of blocking the relay shall be decided between the purchaser & tenderer after carrying out measurements as in 13.1. To start with, the relay shall be blocked for operation in case 2nd harmonic current exceeds 15% of the fundamental current.

u) The relay shall discriminate correctly between faults in the forward and reverse directions on the event of voltage input to the relay falling down to 0 V. To maintain a correct polarizing (directional reference) signal for the distance element and to enable fast operating time under conditions of close-up faults, the relay shall utilize memory polarization. The polarizing signal shall be derived from sufficient samples of the pre-fault voltage held in memory.

9.2 High impedance type differential protection relay for bus bar.

Protection against bus faults shall be provided by means of a sensitive high impediance differential protection relay. The relay shall be of the high speed type and operation in less than 40 milli-seconds for 2 times the rated current and in less than 15 ms at current of 10 times the set value. The following features shall be incorporated in the relay.

The setting of the relay shall be suitably adjustable in appropriate steps. The relay shall have overload current handling capabilities upto 2 times the set current permanently & 40 times the set current for one second. The relay shall not operate for maximum through fault current. Suitable number of out put trip contacts shall be provided on the relay to tripthe desired CBs simultaneously.

9.3 Definite Time over current relay 9.3.1 Directional definite time over current relay with instantaneous over current element at

TSS.

A definite time over current protection shall be used with an adjustable current setting ranging from 0 to 50 Amp and time setting from 0 to 5000 ms, with an instantaneous over current element, adjustable from 0 to 100 Amp, which clear faults at the sub station. The instantaneous element shall be with operating time not exceeding 20+2 ms for the set current. Below the set current there shall be no operation of the relay. The error shall not exceed + 5 % the set currents.

9.3.2 Directional definite time over current relay at SSP/SP A definite time over current protection shall be used with an adjustable current

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setting ranging from 0 to 50 Amp and time setting from 0 to 5000 ms. 9.4 Wrong Phase coupling prevention Relay

An impedance relay for protection against wrong phase coupling which shall

operate on the principle that the relay identifies a wrong phase coupling condition when the impedance lies between 2 to 60 ohm with adjustable lower & higher impedance range and its angle lies in the second quadrants between 110o to 150o in the R-X plane. All parameters expressed are in secondary values. The relay shall be immune to the regenerative currents.

Logic Based Intelligent Auto recloser

9.5.1 Whenever a feeder circuit breaker is tripped due to operation of the following

feeder protective relays, namely distance, wrong phase, high impedance earth fault relay and instantaneous over-current relays, the concerned auto reclosing scheme shall close the breaker after a pre-set dead time of 0.5 second (adjustable from 0.1to 1 seconds). If the breaker trips again due to persistence of fault during the reclaim time 30 seconds (settable 6 to 60 seconds) of the auto reclosing scheme, the scheme shall get locked out.

9.5.2 It shall be possible to reset the locked out state either locally or through remote

control. Necessary contacts for telesignalling the locked-out state and for resetting the same shall be provided for interfacing with the remote control equipment. Irrespective of whether the auto reclosing scheme is in the normal condition or in the locked out condition, it shall be possible to operate the circuit breaker locally as well as through remote control.

9.5.3 A single shot high-speed auto-reclosing scheme shall work in conjunction with the

Master Trip relay to operate the feeder circuit breaker. The auto-reclosing scheme shall be designed for a dead time adjustable between 0.1 and 1 second in steps of 0.1 second (normally to be set at 0.5 second) and a reclaim time adjustable between 6 and 60 seconds (normally to be set at 30 seconds, the operating duty of feeder circuit breaker being 0-0.3s –CO –30 s- CO).

9.5.4 Any section is fed from both sides by circuit breakers at adjacent switching posts – one on the TSS side and next on the other side. A fault on the OHE is cleared from both directions so as to isolate the minimum possible section. After tripping, auto-reclosure operates, and closes CB on TSS side first. Other side CB shall close after assurance that the fault of temporary nature has been cleared. This shall be ensured by the auto-reclosure of other side CB, which shall continue to sense the PT supply remains for a period as set in the reclaim time, the auto-reclosure shall close the other side CB. 9.5.5 The auto reclosure shall be blocked in the event of high current earth faults above 2000 to 10000 in steps of 1000 Amps on the OHE. Suitable sensing circuits shall

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be available for the relay from the current transformer to activate the bypass. The tenderer shall make relay settings accordingly. A manual over -ride of this blocking shall be provided. 9.5.6 The auto reclosure shall have facility to repeat the reclosing on the fault again for the second time after a time lag settable from 10 sec to 60 sec in steps of 1 sec during the reclaim time. Such facility can be switched ON or OFF by the purchaser to his requirements. Such reclosures however shall be automatically blocked in event of high current earth fault for the set currents as explained in para 9.1.2(l) & 9.4.5 or a fault detected by the distance relay in the 2nd zone or beyond. 9.6 High Impedance Earth Faults (back up) 9.6.1 Instances of low current faults not getting deleted by distance protection relays have been reported. Such faults sometimes get cleared by the transformer OCR (IDMT) relay after a considerable period which may be dangerous. 9.6.2 Protection against such high resistance earth faults shall be provided by a vectorial delta I type of relay. The relay shall work on the principle of detecting Delta I scalar as well as the vectorial components of the delta I current to decide the tripping of the relay. Also the relay shall have blinders of range 0.5 to 30 Ohms (selectable in steps of 0.1 Ohms). A trip command shall be generated after evaluating both the Scalar and Vectorial component of the delta I. 9.6.3 The relays sensitivity shall be restrained by 50 % if second harmonics are more than 12% and/or third harmonics are more than 15%. The setting range of the relay shall be from 1 amp to 6 Amps settable in the steps of 0.1 Amps. The accuracy of current setting shall be + 7.5 %. The restraining features of the relay shall be reviewed along with RDSO after the measurements at 13.1 have been completed. 9.6.4 The relay shall act as a back up to the main directional distance protection. The relays operating time in no case shall be more than 70 ms Additional time delays of 500 ms settable in steps of 25ms shall be provided to the relay. The relay shall continuously sense the status of feeder protection relay and the MTR and give trip command to the breaker only when these relays have failed to clear the fault. Detailed calculations for the setting of the relays shall be carried out by the tender and approved by RDSO before actually putting in the field. 9.7 Reverse power flow prevention Relay

In case of double-ended feed, reverse flow of power back into the grid from the energized TSS is required to be prevented beyond a set limit. A suitable reverse power relay shall be provided, sensing power from the 25kV side to trip the primary CB in case the reverse power flow beyond the set regenerative reverse power levels. The relay shall be set based on amount of reverse power and operate on time delay. The reverse power

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(current) shall be settable from 0 to 5 A (in steps of 0.01 A) and time delay from 0 sec to 30 sec. (in steps of 0.5 sec). 9.8 Panto Flashover prevention/signalling relay 9.8.1 Provision of this relay and associated communication media and interface equipments at TSS/SSP/SPs shall be optional and provided if demanded specifically by the Purchaser. Purchaser shall clearly specify whether the concerned subsector is to be made dead by panto flashover relay or flasher light indication is tobe given for warning locomotive drivers as per clause No.9.8.6. 9.8.2 In the event of a tripping of circuit breaker(s) due to intermittent fault on one of the sides of the FP /IOL and an electric train entering from a live to a dead section of the IOL, a heavy flash - over may occur, when the pantograph negotiates the IOL, depending on the intensity of current being drawn, with chances of consequential damage to OHE. In case of transient faults, auto reclosure of CB would obviate this but in case of persisting faults or it reclosure gets delayed, the possibility of flashover will exist. 9.8.3 Such needs be managed by ensuring that the live subsector is made dead by tripping the concerned CBs simultaneously. A logic for various such conditions in which tripping of both CB’s of the FP IOL required shall be generated by a microprocessor based logic/suitable relay scheme and whenever such trippings are required the same shall be identified and done by the relay. Further, the relay shall have give tripping command to the concerned CB at adjoining TSS/SSP/SP to make the live subsector dead. 9.8.4 Detailed calculations of tripping time, train operation time, relay operating time and the CB tripping time shall be done by the tenderer and approved by RDSO before developing the relay. The relay shall be developed in lines with RDSO specification no. TI/SPC/PSI/PROTCT/2982 or latest. 9.8.5 For making the live subsector dead, Pantoflashover relay to be provided at TSS/SSP/SP shall have communication features and necessary interface. On its actuation relay shall give trip command to the circuit breaker at the concerned post and through its communication trip the circuit breaker at adjoining post (TSS/SSP/SP) so as to make the concerned sub-sector dead. The details of communication media between different switching control posts (TSS/SSP/SPs) shall be furnished along with cost as option. The purchaser may get this communication media supplied / erected from the tenderer or can separately procure / erect between the posts as per the technical requirements given by the tenderer. Works related to interfacing the communication media and C&R panel shall be done by the successful tenderer. The tenderer shall also provide a continuous monitoring system for this communication link and in case the communication link become ineffective/ disconnected/short circuited an alarm shall be sounded to the user. 9.8.6 The relay in addition will be capable of closing a contact for initializing a flasher light for warning locomotive drivers. Suitable relays / contacts capable of handling the flasher light current shall be provided by the tenderer. The flasher light shall be capable

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of working independently whether the communication links between the adjacent SSP, TSS exists or not. The provision of the contactors & flashers light for warning & power supply for the flasher lights and outside the scope of work to this specification. 9.9 Master trip Relay

The relays as explained above in item 9.1, 9.2, 9.3 shall trip the corresponding feeder circuit breaker in case of fault, through a high speed self-reset type tripping relay to be designated as Master Trip relay. The relay shall have a operating time of not more than 12 ms and a resetting time of not more than 100 ms. The relay shall be capable of handling the current of the CB trip coil.

10.0 DETAILS OF 25 kV CAPACITOR BANK PROTECTION

(applicable, if asked for by the purchaser) The protection system for capacitor bank if asked for by the purchaser in the tender shall be as per the relevant RDSO specifications of capacitor bank viz. ETI/PSI/67 (11/96) with A&C slip no. 1 to 7- for shunt capacitor bank or TI/SPC/PSI/THYCAP/0030- for thyristor switched capacitor bank or any other latest RDSO specifications. 11.0 OTHER RELAYS AND PROTECTION 11.1 Low Voltage Tripping at the SP

An instantaneous under voltage relay shall be provided by the tenderer to trip the

bridging interrupter or circuit breaker at the neutral section in case of under voltage during emergency feed conditions. The relay shall be connected to one of the existing PT Type II and shall have voltage settings of 19 kV, 17 kV and 15 kV below which if the voltage at the SP drops the sectioning circuit breaker shall operate. 12.0 INSPECTION AND TESTING 12.1 General

The inspection of the control and relay panel shall be carried out by an authorized representative of the purchaser. Prototype inspection shall be done by RDSO. After successful completion of all the type and routine tests as per this specification, prototype approval shall be issued by RDSO. After approval of prototype, inspection and routine tests on the balance quantity shall be done by the authorized representative of the Indian Railways as per purchase order. 12.1.1 Only after all the design and drawings have been approved and clearance given by Research Design and Standards Organization (RDSO) to this effect, the manufacturer may take up manufacture of the first prototype unit for RDSO inspection.

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12.1.2 Before giving the call to RDSO for inspection and testing of the prototype of the equipment, the manufacturer shall submit a detailed test schedule consisting of schematic circuit diagrams for each of the tests and nature of the test, venue of the test and the duration of the test and the total number of the days required to complete the tests at one stretch. He should have carried out the routine tests himself and ensured that the relay and the C&R panel is as per SOGP and this specification. The inspection call shall be given 30 days in advance from the actual inspection date at the factory. 12.2 TESTS The entire prototype test on all the relays and control and relay panel shall be carried out by RDSO engineers at the manufacturers works before the dispatch of the first set of relays. Tests conducted at a prior date shall not be acceptable if not conducted in presence of RDSO. The cost of the testing shall be borne by the tenderer. 12.2.1 Type Tests

The relays shall be type tested as per IS:3231, IS:8686 & relevant IEC. All instruments, interposing CTs and any other equipments as the purchaser may desire shall be type tested as per the latest version of respective standard IS/IEC Specifications applicable. The following type tests shall be carried out on the prototype relays.

i) Temperature rise of the coil of the relay shall not exceed the limits of 55 oC

and 80 oC for Class- A and Class-B insulation respectively. ii) Mechanical endurance test for 10,000 operations. iii) Operating time test. iv) Quadrature test v) Reset value test. vi) Reset time test. vii) Making and braking capacity of contacts viii) Overload test ix) Impulse voltage withstand tests applicable test voltage class-III. x) High frequency disturbance test applicable to test voltage class-III. xi) Vibration test on the complete panel at a frequency 16.7 Hz, maximum

amplitude 0.4mm, 10 minutes each for back and forth for right and left and for up and down. After this test the operational characteristics of relays will be confirmed.

xii) Verification of characteristics of relays

xiii) Environmental Tests :- (1) Dry heat test as per IEC 60068-2-2 (1974) (2) Damp heat test, steady state as per IEC 60068-2-3 (3) Damp heat test, cyclic as per IEC 60068-2-30 (1980)

xiv) EM Compatibility tests: - (1) Interference suppression as per IEC 60255-92-1 - 1 MHz burst test, 2.5

kV common mode & 1.0 kV differential mode. Test duration - more than 2 secs.

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(2) Immunity to Electrostatic discharge as per IEC 60255-22-1 (3) Immunity to Radiated EM energy as per EN 61000-4-3, 80 – 1000 MHz,

10 V / m, Antenna, greater than 1 m from all sides. (4) Electrical Fast Transient or burst requirements as per IEC 60255-22-4 (5) Surge Immunity as per IEC 61000-4-5 (6) Immunity to conducted disturbances. (7) Power Frequency Magnetic Field Immunity. (8) A.C. ripple in D.C. auxiliary

xv) In addition to the above, all routine tests detailed in Clause 12.2.2 below shall also be carried out on the first prototype.

Only after clear written approval of the results of the tests on the prototype is

communicated by RDSO/Purchaser to the manufacturer, he shall take up bulk manufacture of the equipment – which shall be strictly with the same material and process as adopted for the prototype. In no circumstances shall material other than those approved in the design/drawings and/or the prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype. 12.2.2 Routine tests

All relays, instruments, interposing CTs and other equipments shall be subjected to routine tests at the manufacturer’s works as per the relevant standards. The following checks and tests shall be carried out on the complete control and relay panel: 12.2.3 Visual Checks

General check of the control board in respect of construction, wiring, provision of various equipments/relays etc. 12.2.4 Operation Tests

Operation tests on all equipments, switches and tests to prove correctness of wiring of various circuits including indications, alarms, operation of relays and annunciation etc. 12.2.5 Power frequency high voltage withstand test

Voltage test on the panels with all equipments and wiring for a withstand voltage of 2 kV (rms) to earth for one minute. 12.2.6 Insulation Resistance test

Measurement of insulation resistance of the complete panel wiring, and circuit by circuit, with all equipments mounted on the panel, by using 1000 V meggar.

12.2.7 Auxiliary Power Consumption test Power consumed by the panel with and without protective relays at 110 v d.c.

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13.0 ERECTION, COMMISSIONING AND PROVING TESTS 13.1 The Tenderer shall carry out the following test along with purchaser for ascertaining the different parameters / values to be used for relay setting and its normal functioning.

i) Harmonic analysis of each TSS on Primary and secondary side for current and voltage harmonics for a period of 7 days.

ii) Wave form recording and analysis of each an every fault occurring on the OHE for a period of six months.

iii) Actual field measurements of R & X value of the OHE in each sub sector and including the values of rail impedance, earth wire impedance and OHE impedance.

iv) To develop fault current characteristics v/s fault clearing time characteristics and evolve which relay shall clear the fault for various recommended range of settings of the relay to evolve time coordination and setting of various relay times for effective coordination of the relays.

v) To record actual transient voltages coming on the 25 kV side for a period of six months.

vi) Magnetic inrush currents generated due to switching on the traction transformer and locomotive/EMU transformers shall be measured at site and harmonic contents of inrush current determined for magnetic inrush period.

vii) Power factor on the 25 kV side of the TSS recorded for one month in order to determine the maximum, minimum and average power factor at the TSS.

viii) Regenerative braking current fed back into the grid recording for a period of one month.

ix) Ferro-resonance studies shall be carried out for each TSS location to ascertain the possibility of any sub-harmonic resonance effect on the system during the initial switching ‘ON’ of the supply.

x) Testing of impedance bonds of S & T department for their satisfactory behaviour on harmonic load current and fault current impact on impedance of the bond.

13.2 The erection and commissioning of relay shall be done by the successful tenderer who shall arrange all tools, plants, instruments and other material required for the purpose at his own cost. Tests shall be carried out during erection/commissioning of the relay at the site in accordance with the testing guidelines finalized with RDSO. Tests shall be carried out on the relay in the presence of the purchaser’s representatives to check the erection and commissioning of the relay. 13.3 Three sets of the test report shall be supplied by the manufacturer to the purchaser for records and reference. 13.4 Proving tests of protection system shall be done by the tenderer by actual simulation of the faults in the field. The location of fault simulation shall be furnished by

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tenderer to RDSO for approval. The protection system will be considered acceptable if the dependability index is nearly 100% during the proving tests. 13.5 Commissioning of the protection scheme shall be done instages from one end of the section under conversion. Satisfactory performance of section with two TSSs including its parallel operation shall be observed for a limited period of minimum two months. Any changes / modification required in the relays and C&R panel during above period shall be carried out and shall be implemented in the subsequent sections without any financial implications. 14.0 TECHNICAL DATA AND DRAWINGS 14.1 The tenderer shall furnish guaranteed performance data, technical and other particulars for the equipment offered in the Performa attached as Annexure-4. 14.2 The tenderer shall furnish their compliance or otherwise against each clause/sub-clause of the technical specification. If the tenderer wishes to deviate from the provision of any clause/sub –clause, he shall furnish the full details with justification for such deviation. 14.3 The tenderer shall furnish descriptive pamphlets and the recommended relay setting and time coordination with supporting calculations for complete protection scheme. The range of setting available, calibrated in terms of single track OHE, shall be clearly stated and adjustments available for intermediate setting explained. The scheme shall include the condition of failure of main protection and clearing of fault by backup protection at identified locations. 14.4 Successful tenderer shall be required to submit the following detailed outline dimensioned drawings (including reproducible copies as per the Railways standard sizes of 210 mm x 297 mm or multiple thereof for approval). Also the approved drawing shall be submitted in AutoCAD-14 or latest on a CD ROM.

(i) Dimensioned drawings of the control & relay panel indicating front and rear views with the layout of instruments, mimic diagram, control switches, indication LED’s, push buttons, protection modules and other equipment’s etc. clearly marked.

(ii) Exploded view of the rear and front of the system indicating the disposition of various equipments inside the control, protection and metering system.

(iii) Schematic diagram of D.C. control circuits for transformer protection, OHE protection, capacitor bank protection and control of circuit breakers, interrupters and motor-operated isolators (if any).

(iv) Schematic diagram of alarm, indication circuits and event logging system. (v) Schematic diagram of A.C. circuits showing connection of CTs and PTs and

associated protective relays. (vi) Drawing showing the legend of various reference/codes adopted for

equipments, protection modules and all other accessories used in the control, protection and metering system.

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(vii) Drawing for name plates/identification labels engraving details. (viii) Any other drawings considered necessary.

15.0 OPERATION, MAINTENANCE INSTRUCTIONS & TRA INING 15.1 The Control and Relay panel shall be maintenance free generally not needing any maintenance, however the tenderer shall mention a maintenance schedule which shall be detailed enough to guarantee failure free service of the relay to the purchaser. The supplier shall supply free of cost 5 copies to the consignee of the Instruction Manuals for operation and maintenance of the equipment. The manuals shall contain full particulars of various components, full dimensioned drawings and circuit diagrams. The manual shall be approved by RDSO prior to the issue to the consignee. 15.2 The tenderer shall train free of cost 10 of the associated engineers/supervisors for 7 days in the maintenance, operation, relay setting procedure, trouble shooting and commissioning of the relay. This training shall be done at the installation site and shall be given to the basic users. The purchaser shall ensure that he gives to the supplier technically competent officials for the purpose of this training. Graduate engineers shall be preferred for this training. 15.3 The tenderer shall quote separately for maintenance tool, kits and test instruments required for satisfactory maintenance and operation of the relay. The test kit / jig shall be complete in all respects to test the individual cards of the C&R panel and the complete kit as a whole. The tenderer shall quote for spares require for the relay for 5 years of trouble free operation beyond the warranty period. 15.4 The successful tenderer shall develop & provide a maintenance schedule and a trouble shooting chart for effective, reliable and trouble free relay operation. The basic maintenance schedule along with the troubleshooting, diagnostic chart shall be submitted to RDSO and approved by RDSO prior to commissioning of the relay for the first time at the sight. 15.5 The successful tenderer shall submit two sets of guide lines for relays setting along with time coordination and supporting calculations, for complete protection scheme to RDSO for scrutiny and approval before commissioning of the panel. After successful completion of commissioning and proving tests in field the tenderer shall submit final relay setting guide line to RDSO for scrutiny and approval. Five copies of approved relays setting guide line shall be supplied to purchaser and two copies to DG (TI) RDSO Lucknow for record. 15.6 The successful tenderer shall develop erection and commissioning manuals, operating manuals, trouble shooting guidelines and after its approval by RDSO shall supply five copies of to the purchaser and two copies to DG (TI) RDSO Lucknow for record. 16.0 WARRANTY

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16.1 The control and relay panel supplied against a purchase order/contract in which this specification is quoted, irrespective of original individual equipment (imported /indigenous) shall be guaranteed for trouble – free and satisfactory performance for a period of 30 months from the date of supply or 24 months from the date of commissioning, whichever period is earlier, details of warranty clause, the extent of responsibility and other relevant aspects shall be included in the purchase order or the contract. The tenderer shall furnish detailed terms and conditions in this regard in his offer. 16.2 The successful tenderer shall make necessary arrangement for closely monitoring the performance of the relay through periodical (preferably continuously for the first year and once a month during the second year of the warranty period) visits to the relay installation TSS for on the spot detailed observations. Arrangements shall also be made for spare parts modules and other items to be kept readily available with the manufacturer/ supplier / successful tenderer to meet exigencies warranting replacement so as to put back the relay in service without unduly affecting the operations of the TSS. 17.0 SERVICE SUPPORT AFTER WARRANTY AND AMC 17.1 The tenderer shall confirm the maintenance support of the relays / C&R panel supplied by him for a period of at least 10 years from the date of commissioning on the panel. The tenderer shall quote for maintenance spare, which the purchaser should have for maintaining of the relays, C&R panel for a period of 5 years. The tenderer shall also quote in his offer the maintenance equipment, instruments and T & P, which the tenderer should have in order to maintain the relays and the C&R panel effectively. 17.2 The tenderer shall also quote for an option of maintaining the entire C&R panel by him for a period of 10 years after the date of warranty period. Such AMC shall include supply of all the material required for maintenance, repairs of relays and testing of the relays at periodic intervals. The tenderer shall take necessary measures to ensure that the downtime of the equipment is the least.

Purchaser may incorporate clause in the tender documents for AMC such that

payments are based on the availability/ downtime of the equipment in slab rates. A fixed period of time after communication of the failure, for which downtime shall be reckoned, will be decided by the purchaser/ railway. 18.0 SPECIFICATION CONFIRMATION 18.1 The tenderer shall go through each and every clause, drawings, Annexure of this specification and indicate compliance to the specification. If there are deviations, detailed reasons for the deviations supported by calculations, drawings, international practices shall be essentially required for evaluating the tender offer. Wherever such deviations have not been furnished it shall be deemed to be understood that the tenderer has accepted all the tender conditions as mentioned in the specification.

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18.2 The tenderer shall also enclose the schedule of guaranteed particular of the relay/ C&R panel in the format as mentioned in the Annexure 4. Extra information to bring out the schedule of guaranteed particulars more effectively may be included separately.

18.3 The tenderer is advised to refer the material schedule for the particular section as enclosed by the tenderer in the proforma as in Annexure 5. Tenderer shall go through the Annexure 5 material schedule in details and submit his offer accordingly. Any clarification, understanding of the requirement shall be clarified from the purchaser by the tenderer before submitting his offer. Any minor modification essentially required for successful integration and working of the Scheme/System shall be considered to be well within the scope of the tenderer.

19.0 TENDERER’S CREDENTIALS

The tenderer shall be a RDSO approved supplier for protective relays on I.R. for the past 5 years or shall be a firm of International repute supplying protective relays to railways for at least 5 years. The tenderer shall enclose necessary documents in support at the time of submitting his offer. The tenderer should have been involved in developmental activity for developing the main feeder protection relays for Indian Railways or any other Foreign Railways.

20.0 IMPORTED RELAYS

The tenderer shall clearly specify at the time of tendering whether any imported relays are being provided. If so the technical details of the relays shall be indicated by the tenderer. All such relays are required to be type tested at manufacturer works abroad by RDSO representatives before dispatch of the relays to the purchaser.

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LIST OF ABBREVIATIONS ANNEXURE 1 Abbreviation Full Form of the Abbreviation

A Amperes

AFTC Audio Frequency Track Circuit

AMC Annual Maintenance Contract

ASNS Automatic Switched Neutral Section

BT Booster Transformer

C&R Control and relay panel

CB Circuit Breaker

DCTC DC Track Circuit

DMT Definite Minimum Time lag

GPS Global Positioning System

GTO Gate Turn Off Thyristor

IDMT Inverse Definite Minimum Time lag

IED Intelligent Electronic devices

IOL Insulated Overlap

LCD Liquid crystal diode

LED Light emitting diode

MSG Maintenance Study Group.

MTBF Mean Time Between Failure

MTR Master trip Relay

NC Normally closed.

NO Normally open

OHE Over Head Equipment

PTFE Poly Tetra Flouro Ethylene

RC Return Conductors.

RTU Remote Terminal Unit SOTF Switch On To Fault

SP Sectioning Post

SR Self Reset

SSP Sub Sectioning Post

THD Total Harmonic Distortion

TRD Traction Distribution

TRS Traction Rolling stock

TSS Traction Sub Stations

WPC Wrong Phase Coupling

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ANNEXURE 2 DEFINITIONS

Item Definition

Audio frequency track circuit (AFTC)

In AFTC type of track circuit, Audio Frequencies in the range of 1500 Hz to 10000 Hz are used. The traction return is connected through an impedance bond capable of handling the traction return load and fault currents. The center point of it is connected to the traction return from the TSS while the remaining 2 terminals it shall be connected to the rails.

Basic time The shortest operating time of distance protection, for example, the time of the first step or zone in a stepped curve distance-time protection.

Breaking capacity

The maximum current and volt– amperes that the contact is able to interrupt successfully under specified conditions without significant damage to contact.

Contract Means the contract resulting from the acceptance by the purchaser of the tender either in whole or part

DC track circuit

DCTC is the conventional track circuiting generally available in all conventional system where the traction transformer neutral point is connected to one or both the traction rails near the TSS. The masts are earthed by connecting them to the traction rail and on the track circuit portion only one rail is available for traction returns and in the non-track circuit regions both rails are available for the purpose of traction return currents.

Dead time Dead time is the period taken by the auto reclose mechanism to close the breaker after the same would have tripped on fault. In other words, the time from the instant of fault detection up to the instant of closing of breaker by auto-reclose system.

Differential protective system

A unit protective system in which an algebraic comparison is made of primary current at two or more points in the power system.

Double ended feeding

The adjacent TSS are on same phase and are connected in parallel. There may or may not be a neutral section on SP for such feeding arrangement.

Equipment Means all or any equipment considered necessary by the purchaser engineers for the satisfactory operation as a whole of the installation including structure, foundations etc.

Making capacity

The maximum current and volt–amperes the contact is able to make successfully under specified conditions without significant damage to the contact.

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Normally closed contact (NC)

A contact, which is closed when the relay is de-energised.

Normally open contact (NO)

A contact, which is open when the relay is de-energised.

Operating time

The time, which elapses from the appearance of the abnormal conditions, which cause the operation of the protection until the protection initiates tripping or alarm.

Primary The primary side of the transformer shall be defined as the side with incoming voltage from the Supply authority on 220, 132, 110, 22 kV as the case may be.

Protected zone

The part of an installation guarded by a certain protection.

Purchaser The person / agency who has floated the tender for execution of the work on or behalf of the president of India.

Railway Means Railway(s) in whose territorial jurisdiction the work is to be carried out and includes the Government of India, Ministry of Railways (Railway Board), and /or general manager of the railways concerned

Reclaim time

Reclaim time is the duration for which the auto reclosing mechanism remains ineffective after first reclosure of circuit breaker by auto-reclose, irrespective of re-occurrence persistence of fault. In other words, the breaker will not be reclosed second time by the auto-reclose device had the same tripped on fault again within the reclaim time after its first reclosure on the auto-reclose system.

Relay back-up

An arrangement, which provides an additional, relay using the same or different principle of operation from that of the main relay.

Remote back-up

An arrangement at the next station in the direction towards the source which trips after a delayed time if the CB in the faulty section is not tripped.

Secondary The secondary side of the transformer shall be defined as the side feeding the OHE i.e.25 kV side.

Sector Distance between the TSS and the SP

Single ended feeding

The TSS is feeding up to SP which is a neutral section. The phases on either side of the SP are different.

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Sub-sector Switch on to fault (SOTF) feature Synchronise polarization OR memory polarisation

Distance between the TSS and the adjacent SSP/ SP or the distance between the SP and the adjacent SSP/SP. SOTF feature for protective system becomes active once a CB has tripped on a fault. CB is in open condition and when it is closed on fault existing in the system. The feature starts by detecting V0 and I0 in the circuit at the time of closing of the CB as a starting point for the SOTF feature. This feature remains active for a period of around 200 milli-seconds from the time of breaker closing. This feature shall give instantaneous operation of the relay. The relay shall operate for close up faults in the forward direction but it shall restrain for close faults in the reverse direction. To ensure such operation memory polarisation feature shall be provided in the relay for correct direction discrimination.

Tenderer The vendor, supplier who intends to quote for the tender floated by the purchaser. The agency who shall quote for tender floated by the tenderer.

Time lag Intentionally introduced time interval between start and completed operation of the protection.

Track circuit It is the circuit providing passage of traction current through arrangement of track bonding.

Unit protection

A protective system, which is designed to operate for abnormal, conditions inside and remains stable for abnormal conditions outside a specified zone of the protective system.

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ANNEXURE 3

GOVERNING AND RELATED SPECIFICATIONS

The relays shall, unless otherwise specified shall conform too generally to the latest edition of Specifications mentioned below:

IEC 60068-2 Environmental Tests

IEC 60255 -3 Single input energising quantity measuring relays with dependent or independent time.

IEC 255 -6 Measuring relays and protection equipment.

IS-2705 (Pt. IV) Protective current transformers

IS 3231 Electrical relays for power system protection

IS 8686 Static protective relays

IS-2705 (Part I to IV) Specification for Current Transformer IS-3156 Specification for Potential Transformer IS-4237 Switchgear general requirements IS-5578 & 11353 Panel wiring IS-8623 Factory built assemblies of switchgear and control gear

for voltages unto and including 1000V a.c. and 12V d.c.

IS-8828 Miniature circuit breakers IS-9224 HRC cartridge fuse IS-6875 Control switches/push button IS-1248 Indicating instruments IS-2147 Degree of protection IS-694 PVC insulated cables for working voltages up to and

including 1100 V IS-10810 (part 53) Methods of test for cables: part 53-flammability test

The above specifications shall be applied in a manner altered, amended or supplemented by this specification and the latest Indian Electricity Rules wherever applicable. Any deviations from the specifications proposed by the tenderer at the tender/prototype stage, to improve the performance, utility or efficiency of the equipment shall be given due considered provided full details of the deviation are furnished by the tenderer to the satisfaction of the purchaser. In such cases the tenderer shall quote according to the specification as well as with the deviations from the specifications.

625

Other related and linking specifications of the equipment to which the relays get linked or derive signals are –

TI/SPC/PSI/PTs/0990 220/132//100/66/25 kV PTs

ETI/PSI/90(6/95) with A&C 1&2

25 kV current transformer

ETI/PSI/117(7/88) with A&C 1 to 6

220/132/100/66 kV current transformer

TI/SPC/PSI/CB/0000 For 25 kV single poles, double pole and primary side 22 kV, 66 kV, 100 kV, 110 kV, 132 kV and 220 kV two pole/three pole vacuum and SF6 CBs for AC traction substations.

ETI/PSI/167(9/97)

25 kV interrupter

ETI/PSI/163(4/97) with A&C 1 21.6 MVA, 100/27 kV,22/27 kV single phase ONAN traction power transformer

ETI/PSI/120(2/91)

Code of practice for earthing

TI/SPC/PSI/PROTCT/2983 Prototype specification of pinto flashover protection relay for 25 kV system

ETI/PSI/65(1/97) with A&C 1

Specification for C&R panel with static relays

TI/SPC/PSI/PROTCT/1982 Prototype specification for delta I fault selective relay for fault selective system.

TI/SPC/PSI/OFC/0050 Specification for 24 core armoured optic fibre cable for use in Indian Railway Traction Installation System.

626

SCHEduled of guranteed particular for SPECIFICATION NO. TI /SPC/PSI/PROTCT/4050

(TO BE SUBMITTED BY THE TENDERER AT THE TIME OF SUBMITTING HIS TENDER OFFER) The tenderer shall be required to submit the following detail to the purchaser at the time of tender scrutiny in order to technical capability of the tenderer to carry out the work. AMBIGUOUS or incomplete information like “_”Or “shall be given later” can lead to technical rejection of the other. WHEREVER deviation is quoted they shall be supposed to be supported with detailed technical benefits and/or financial benefits. S.No. Description Manufacturer’s details 1.0 General Name of the manufacturer Governing specifications TI/SPC/PSI/PROTCT/40

50 Are you an RDSO approved firm? 1.4 Have you been a regular supplier to Indian Railways

for past 5 years

1.5 Have you gone through the specification in details? Attach a point wise compliance for each item as an Annexure whether you shall be able to do the specific item of the specification or not. Indicate clearly the clause number of the specification not acceptable to you. And give details, elaborate reasoning for clauses not acceptable to you.

1.6 Does your company have a formal setup for training? Elaborate training facilities and your experience in preparation of quality training materials.

2.0 System Particulars 2.1 Have you gone through the specification in details

and also visited site of work to understand the in depth requirement of the tender.

2.2 Will you be able to provide the scheme with the desired accuracies so that up to 90 % of the trippings occur only in the zone in which the fault occurs?

2.3 Will you be able to provide the scheme in a manner explained in the specification so that there is no impact whether the bus coupler CB’s at SSPs & SPs are open OR closed condition, provided or not provided and adjacent TSSs are operated in parallel or not.

2.4 Name the relays, which shall be required to be developed by you as per this specification.

627

2.5 Whether any relay used is an imported relay. Confirm that the relay shall be tested by RDSO at its works abroad before dispatch of the relay for Indian Railways.

3.0 Particulars of C & R Panel Units Values/details 3.1 Rated control voltage with

variation Volt DC 110VDC +15/-30%

3.2 Rated VA burden on CTs & PTs

VA Less than rated VA burden of CTs and PTs

3.3 Power consumption Watts 3.4 Impulse and power

frequency withstand voltage values

kVp & kVrms

Impulse withstand voltage of 5kVp wave of 1.2/50µs and power frequency withstand voltage of 2kVrms for 1 min.

3.5

Dimensions: Length Width Breadth Weight of the relay

mm mm mm grams

1100 1900 duplex & values are 2300 indicative and actual sizes shall be decided during drawing approval

3.6 Rated Vibration withstand microns As per clause 12.2.1(xi) 3.7 Shall the test kit for relay

testing be supplied? If yes enclose technical particulars.

3.8 How shall the C&R panel be interfaced with SCADA Serial Port or Hard wiring

3.9 Are there any deviations to the RDSO specifications? If yes enclose clause wise deviations and reasons of deviations.

4.0 Particulars of HV bus bar differential protection Units Values/details 4.1 Manufacturer 4.2 Relay Identification number 4.3 Range of relay setting provided for the

relay % 20 to 50% in steps

4.4 Error in operating current for a set value of current.

% +/- 5%

4.5 Error in operating time for a set value of current.

% +/- 10%

628

4.6 Resetting time of the relay milli sec < 50ms 4.7 VA burden of the relay VA <0.2VA 4.8 DC power consumption of the relay Watt <5 watt 4.9 Short time current withstand capacity of

the relay for 1 sec Amps 40 times the set current for

1 sec. 4.10 Rated making & breaking capacity of

contacts Amps 30A for 3 sec

4.11 Rated D.C. voltage variation range for which relay operation is guaranteed

Volts 77V –126.5VDC

4.12 Rated relay voltage for the D.C. circuit Volts 110VDC 4.13 Rated relay current for the D.C. circuit Amps <0.2/110A 5.0 Particulars of Instantaneous Over Current Relay Units Primary Side of

transformer 5.1 Manufacturer 5.2 Relay Identification number 5.3 Setting range of the relay % of 5 A 400-600% of 5A 5.4 Operating time at set current, 2 times set

current, 3 times set current & 4 times the set current.

milli-sec <20ms

5.5 Operating time at 5 times the set current milli -sec <20ms 5.6 Accuracy of operating time/Class +/- milli -

sec +/-10% i.e. +/- 2 ms

5.7 Resetting time of the relay milli -sec <50ms 5.8 VA burden of the relay VA 0.2VA 5.9 DC power consumption of the relay Watts <5watt 5.10 Short time current carrying capacity of the

relay for 1 sec Amps 40 times the set current

5.11 Current carrying capacity of the contacts (normal)

Amps 5A

5.12 Current carrying capacity of the contacts (short duration 1 sec)

Amps 30A

5.13 Rated making & breaking capacity of the contacts.

Amps 30A for 3 sec

5.14 Rated D.C. voltage variation range for which relay operation is guaranteed.

Volts 77-126.5VDC

5.15 Rated relay voltage for the D.C. circuit Volts 110VDC 5.16 Rated relay current for the D.C. circuit Amps <0.2/110A 6.0 Transformer OCR IDMT Units Primary Side 25 KV

side 6.1 Manufacturer 6.2 Relay Identification number

629

6.3 Characteristics of the relay 3 sec curve at 10Ir

3 sec curve at 10Ir

6.4 Current setting range % of 5 A 80-320% of 5A 80-320% of 5A

6.5 Time multiplier setting range 0.1 to 1 0.1 to 1 6.6 Error in operating current for a set value

of current. % +/-10% +/-10%


% +/-10% +/-10%

6.8 Resetting time of the relay milli sec <50ms <50ms 6.9 VA burden of the relay VA 0.2 0.2 6.10 DC power consumption of the relay Watts <5 watt <5 watt 6.11 Short time current carrying capacity of the

relay for 1 sec Amps 100A 100A


Amps 30A for 3 sec 30A for 3 sec


Volts 77-126.5VDC 77-126.5VDC

6.14 Rated relay voltage for the d.c. circuit Volts 110VDC 110VDC 6.15 Rated relay current for the d.c. circuit Amps <0.2/110 A <0.2/110

A 7.0 Earth Leakage Protection Relay Units Primary Side 25 kV

Side 7.1 Manufacturer 7.2 Relay identification number 7.3 Setting range of the relay 10 to 80 % in

steps of 5 % 10 to 80 % in steps of 5 %

7.4 Operating time at 2, 3 & 4 times the set current

milli sec. 20+/- 2 ms 20+/- 2 ms

7.5 Operating time at 5 times the set current milli sec. <20ms <20ms 7.6 Resetting time of the relay milli sec. <50ms <50ms 7.7 VA burden of the relay VA 0.2 0.2 7.8 DC power consumption of the relay Watts <5 watt <5 watt 7.9 Short time current carrying capacity of the

relay for one second Amps 100A 100A


Amps 5A 5A

7.11 Current carrying capacity of the contacts (short duration 1-second)

Amps 30A for 3 sec 30A for 3 sec

630


Amps 30A(AC)(M) and 5 A & 0.5A

30A(AC) (M) and 5 A & 0.5A


Volts 250VAC. Cosφ = 0.4 220VDC, L/R=45ms

250VAC. Cosφ = 0.4 220VDC, L/R=45ms

7.14 Rated relay voltage for the D.C. circuit Volts 110VDC 110VDC 7.15 Rated relay current for the D.C. circuit Amps <0.2/110A <0.2/110

A 8.0 Transformer Differential Relay Units 8.1 Manufacturer 8.2 Relay Identification number 8.3 Range of relay setting provided for the

relay % Current setting: 15 to 80 %

in 8 steps. 8.4 Current limit for which the relay shall not

operate for inrush currents Times of set current

5 times


% +/-5%


% +/-10%

8.7 Resetting time of the relay milli sec <50ms 8.8 VA burden of the relay VA <0.2VA 8.9 DC power consumption of the relay Watt <5W 8.10 Short time current withstand capacity of

the relay for 1 sec Amps 40 times the set current

8.11 Range of bias setting % Bias setting: 15 to 50% in min. 3 steps and max. 6 steps.

8.12 Whether the relay shall be effective for changes in the taps of the transformer from –15 to +15%?

Yes

8.13 Whether relay should be insensitive to through fault up to 5 times the set

Yes

8.14 Whether the relay shall lock out in case 2nd harmonic are more than 15%

Yes

8.15 Whether suitable interposing C.T. shall be supplied

631

8.16 Rated making & breaking capacity of contacts

Amps 30A(AC)(M) and 5 A, 250VAC, Cosφ = 0.4 & 0.5A


Volts 77V-126.5VDC

8.18 Rated relay voltage for the D.C. circuit Volts 110VDC 8.19 Rated relay current for the D.C. circuit Amps <0.2/110A 9.0 Inter trip Relay Units 9.1 Manufacturer 9.2 Relay Identification number 9.3 Operating time <12ms 9.4 Accuracy of operating time +/-10% 9.5 Resetting time of the relay <50ms 9.6 DC power consumption of the relay <5watt 9.7 Rated making & breaking capacity of

contacts Amps Making: 30A, 250VAC,

50Hz for 3 sec. Breaking: 5A at 250VAC, 50Hz, Cosφ = 0.4 220VDC,L/R=45ms


Volts 77-126.5VDC

9.9 Rated relay voltage for the D.C. circuit Volts 110VDC 9.10 Rated relay current for the D.C. circuit Amps <0.2/110A 10.0 Reverse power relay Units 10.1 Manufacturer 10.2 Relay Identification number 10.3 Setting range of the relay 0 to 5A in steps of 0.01A 10.4 Operating time at set value milli sec <12ms 10.5 Accuracy of operating time/Class +/- milli

sec

10.6 Resetting time of the relay milli sec <50ms 10.7 VA burden of the relay

CT PT

VA 0.2

10.8 DC power consumption of the relay Watts <5 watt 10.9 Short time current carrying capacity of the

relay for 1 sec Amps 100A


Amps 5A

10.11 Current carrying capacity of the contacts (short duration 1 sec)

Amps 30A for 3 sec


Amps 30A(AC)(M), 5A &0.5A

632


Volts 77-126.5VDC

10.14 Rated relay voltage for the D.C. circuit Volts 110VDC 10.15 Rated relay current for the D.C. circuit Amps <0.2/110A 10.16 Error in operating value +/-5% 10.17 Error in operating time +/-10% 11.0 Differential protection relay for 25 kV bus at TSS, SSP & SP Units 11.1 Manufacturer 11.2 Relay Identification number 11.3 Range of relay setting provided for the

relay % 20-50%


% +/-5%


% +/-10%

11.6 Resetting time of the relay milli sec <50ms 11.7 VA burden of the relay VA 0.2 11.8 DC power consumption of the relay Watt <5watt 11.9 Short time current withstand capacity of

the relay for 1 sec Amps 30A for 3 sec


Amps 30A(AC)(M), 5A &0.5A


Volts 77-126.5VDC

11.12 Rated relay voltage for the D.C. circuit Volts 110VDC 11.13 Rated relay current for the D.C. circuit Amps <0.2/110A 12.0 Directional Numerical distance protection relay with 3 zone and polygonal characteristics Units 12.1 Manufacturer 12.2 Relay Identification number 12.3 Setting available in relays As per clause 9.1.2 12.4 Range in forward & reverse directions.

(Indicate number of zones in forward & reverse directions with operating time

Ohms/Number/milli sec

R&X=0.04 to 50 ohms Zone II operating time 50ms for fault with in Zone I and for the fault beyond the Zone I To= (Xm/Rxm)Tr+Tb

12.5 Range and steps of each settable parameter as available on the relay

As per clause 9.1.2

12.6 Operating time of each element. 12.7 Error in operating value and operating time

of each element. +/-5%

12.8 Resetting time of the relay of each element milli sec <50ms

633

12.9 VA burden of the relay VA 0.2 12.10 DC power consumption of the relay Watts <5 watt 12.11 Short time current carrying capacity of the

relay for 1 sec Amps 100A

12.12 Operating time for I, II, III zone etc. range of setting of additional time delay for zone II & III

milli sec Operating time: 50 m – sec for fault within zone 1 and for fault beyond the zone 1 to = (Xm/Rsm) Tr and Tb = 50 to 150 m Ohm in steps of 10 ms.

12.13 Whether the relay shall act for WPC type of faults

Yes Yes

12.14 Whether regeneration immunity shall be provided for the relay

Yes

12.15 Thermal withstand capability Amps 20 time of rated current for 1 sec.

12.16 Particulars of output relay Make (b) Rating (c) NO, NC Contact details

Amps Amps Number


Amps 30 A(AC) (M), 5A & 0.5 A


Volts 77 V- 126.5 VDC

12.19 Rated relay voltage for the D.C. circuit Volts 110 VDC 12.20 Rated relay current for the D.C. circuit Amps < 0.2/110 A 12.21 Whether 2nd harmonic restraint features as

per clause 9.1.2(t) provided? Yes

12.23 Whether switch on to fault (SOTF) feature is provided?

12.24 Whether synchronous polarization feature is provided?

13.0 Definite minimum time over current relay with instantaneous element for feeder protection at TSS and DTOC relay at SSP/SPs Units 13.1 Manufacturer 13.2 Relay Identification number 13.3 Current setting range

a) Time delay element b) Instantaneous element

Amp 50 A 5000 ms 0- 100 A

13.4 Time setting range Definite 0-5000, Ins 20 +/72


% +/_ 5%

634


% +/- 10%

13.7 Resetting time of the relay milli sec <50 ms 13.8 VA burden of the relay VA 0.2 13.9 DC power consumption of the relay Watts <5 watts 13.10 Short time current carrying capacity of the

relay for 1 sec Amps 30A for 3 sec.


Amps 30 A(AC) (M), 5 A & 0.5 A


Volts 77 V – 126.5 VDC

13.13 Rated relay voltage for the d.c. circuit Volts 110 VDC 14.0 Vectorial Delta I Relay Units 14.1 Manufacturer 14.2 Rated current Amps 5 A 14.3 Setting range & steps Amps 1 to 6 A 14.4 Error in operating current +/- 7.5% 14.5 Error in operating time +/-10% 14.6 setting range of ‘X’ blinder and steps of

its setting 0.5 to 30 Ohms ( in steps

of 0.10 Ohms) 14.7 error in operating ‘X’ value +/- 10% 14.8 Rated short time current for 1 sec. Amps 100 A 14.9 Rated dynamic current Amps 250 A 14.10 Operating time (a) Normal

(b) With timer milli-sec >70 ms

14.11 Rated VA burden VA 0.2

14.12 Power consumption of control circuit Watts <5 watt 14.13 Maximum arc resistance that the relay can

identify Ohm _

14.14 Resetting time milli-sec <50 ms 14.15 Rated current carrying capacity of

contacts Amps 5 A

14.16 Rated breaking capacity of contact Amps 5A & 0.5 A 14.17 Rated making capacity of contact Amps 30 A 14.18 Number of spare NO and NC contacts Number

14.19 Is the relay draw out type? 14.20 Are test terminals/test switches provided? 14.21 Have specimen calculations for the

recommended relay setting been enclosed with the offer?


Volts 77 V- 126.5 VDC

635

14.23 Rated relay voltage for the D.C. circuit Volts 110 V DC 14.24 Rated relay current for the D.C. circuit Amps 0.2/110 A 15.0 Panto-Flashover Protection Relay Units 15.1 Manufacturer 15.2 Operating time milli sec 40 ms +/- 5ms 15.3 Resetting time milli sec 1 sec. 15.4 Rated current carrying capacity of

contacts Amps 5 A continuous at 110

VDC 15.5 Rated breaking capacity of contact Amps 5A & 0.5 A 15.6 Rated making capacity of contact Amps 30 A 15.7 Number of spare

(a) NO contacts (b) NC contacts

Number Number

15.8 Is the relay draw out type or card mounted type

Yes/No

15.9 Whether relay can identify extended feed condition?

Yes/No


Amps As above


Volts 77 V DC – 126.5 VDC

15.12 Rated relay voltage for the D.C. circuit Volts 110 V DC 15.13 Rated relay current for the D.C. circuit Amps < 10/110 A 15.14 Whether the relay shall be able to operate

the flasher/warn lights as also the panto flashover prevention scheme.

16.0 Logic Based Intelligent Auto recloser Units 16.1 Manufacturer 16.2 Relay Identification number 16.3 Range of dead time provided for the relay milli sec 0.1 to 1 sec. 16.4 Range of reclaim time provided for the

relay Sec 6 to 60 sec.

16.5 Whether the second reclose facility is available and can be switched OFF/ ON as per the user’s requirement

Yes

16.6 For high fault level whether the auto reclosure shall be bypassed. If yes what shall be this current range

Yes/No Amps

Yes settable 2000 to 5000 A on OHE Yes

16.7 Whether only one auto recloser shall close when a tripping on fault occurs.

Yes/No 10-60 sec. In steps of 1 sec during reclaim period

16.8 The time after which the 2nd auto recloser shall act for such a case as above.

Sec 0.2

16.9 VA burden of the relay VA

636

16.10 DC power consumption of the relay Watts < 5 watt 16.11 Rated making & breaking capacity of

contacts Amps 30 A(AC)(M),5A&0.5A


Volts 77VDC-126.5VDC

16.13 Rated relay voltage for the D.C. circuit Volts 110VDC 16.14 Rated relay current for the D.C. circuit Amps <0.2/110A 16.15 Rated voltage Volts 110VDC 17.0 Master Trip Relay Units 17.1 Manufacturer 17.2 Relay Identification number 17.3 Operating time milli sec <12ms 17.4 Accuracy of operating time % +/-10% 17.5 Resetting time of the relay milli sec <100ms 17.6 DC power consumption of the relay Watts <10watts 17.7 Rated voltage Volts 110 V DC 17.8 Rated making & breaking capacity of

contacts Amps 30 A(AC)(M), 5A & 0.5A


Volts 77 V DC-126.5 V DC

17.10 Rated relay voltage for the D.C. circuit Volts 110VDC 17.11 Rated relay current for the D.C. circuit Amps <10/110A 18.0 Blower fan Units 18.1 Manufacturer’s Name 18.2 Operating Voltage Volts 240VAC 18.3 Power Consumption at rated voltage Watts 18.4 Whether continuously rated? 19.0 Space Heater Units 19.1 Manufacturer’s Name 19.2 Operating Voltage Volts 240VAC 19.3 Power Consumption at rated voltage Watts 19.4 Whether continuously rated?

637

ANNEXURE 5 MATERIAL SCHEDULE

(To be submitted by the purchaser for tendering) MATERIAL SCHEDULE FOR THE SECTION ____________________________

S.No Item to be provided Quantity required at TSS SSP SP

EQUIPMENT ON THE FRONT OF THE PANEL 1.0 Set of push button switches for control of - 1.1 HV Incoming line breaker and bus coupler

breaker

1.2 Transformer breaker primary side 1.3 Transformer breaker 25 kV side 1.4 25 kV breakers & bus coupler 2.0 Switches for local/remote change over - 2.1 HV Incoming line breaker and bus coupler

breaker

2.2 Transformer breaker on HV side 2.3 Transformer breaker on 25 kV side 2.4 25 kV breakers & bus coupler 3.0 Automatic semaphore indicators for - 3.1 HV Incoming line breaker and bus coupler

breaker

3.2 Transformer breaker on HV side 3.3 Transformer breaker on 25 kV side 3.4 25 kV breakers & bus coupler 4.0 Manually operated semaphore for - 4.1 220 or 132 or 110 or 22 kV isolators 4.2 Isolators on 25 kV side 5.0 Set of Red & Green indication LEDs

for close and open positions of -

5.1 HV Incoming line breaker and bus coupler breaker

5.2 Transformer breaker on HV side 5.3 Breakers for transmission line

sectioning arrangement.

5.4 Transformer breaker on 25 kV side 5.5 25 kV breakers & bus coupler 6.0 Set of push button and annunciation

LEDs for -

6.1 Trip circuit of CB fail (Yellow LED) 6.1.1 HV Incoming line breaker 6.1.2 Transformer breaker on primary side 6.1.3 Transformer breaker on 25 kV side 6.1.4 25 kV feeder breakers

638

S.No Item to be provided Quantity required at TSS SSP SP

6.2 D.C. supply fail for control/alarm and annunciation circuit (yellow LED)

6.3 OHE supply/PT fuse fail (Red LED) 7.0 No. of blue indication LEDs for the blower

fans of each transformer -

8.0 A.C. Ammeters on 25 kV side, Scale 0-600/1200 Amps with associated range selector switch

9.0 A.C. Voltmeter on 25 kV side, Scale 0-30 kV 10.0 A.C. Ammeters Scale 0-200/400 Amps for

220/132/100 kV system.

11.0 A.C. Voltmeter for 220 kV or 132 kV or 100 kV system, Scale 0-260 kV or 0-160 kV or 0-150 kV

12.0 Annunciation system comprising –

12.1 No. of LEDs for annunciation 12.2 No. of columns of LEDs 12.3 No. of rows of LEDs 12.4 Annunciation alarm accept push button 12.5 Annunciation alarm re-set push button 12.6 Annunciation testing push button 12.7 D.C. bell operated off 110 V

(to be mounted inside)

13.0 110 V D.C. supply supervision and annunciation scheme thereof -

13.1 Push button for DC fail alarm test 13.2 Push button for DC fail alarm accept 13.3 Indication LEDs (yellow) for DC fail

indication (240 V a.c)

13.4 A.C (240V) hooter for DC supply fail alarm 14.0 Cut off switches for disconnection of 14.1 110V DC supply to alarm and indication

circuits

14.2 240V AC supply to AC hooter and DC fail indication lamps

15.0 Test switches & test terminal block for use with external meters

16.0 Any other item(s) considered necessary by the purchaser or recommended by the tenderer for meeting the requirement of scheme

639

EQUIPMENT INSIDE THE CONTROL PANEL 1.0 Space heaters with switches (240 V A.C) 2.0 Blower fan with switches (240 V A.C) 3.0 240 V, 5 A, 3-pin socket & switch 4.0 Cubicle illumination incandescent lamp with

two door switches

5.0 Corridor illumination incandescent lamp with two door switches

6.0 Terminal blocks 7.0 HRC or rewirable fuses and links 8.0 Earth links 9.0 Any other items considered necessary

EQUIPMENT ON THE REAR OF THE PANEL (RELAY PANEL) 1.0 For the protection of transformer

1.1 Differential relay 1.2 IDMT over current relay on the primary side 1.3 Instantaneous over current relay on the

primary side

1.4 Instantaneous earth fault relay on the primary side

1.5 IDMT over current relay on the 25kV side 1.6 High speed inter tripping relay (hand reset

contacts)

1.7 Lockout relay (if provided) separately 1.8 Aux.Relays for transformer fault i.e. Buchholz,

excessive winding and oil temperature tripping

1.9 Aux. Relays for transformer alarm i.e. Buchholz, excessive winding, oil temperature and low oil level alarm.

1.10 Interposing CTs for provision in differential protection circuit (to be mounted inside).

2.0 For the protection of OHE - 2.1 Polygonal characteristics 3 zone time graded

distance protection with wrong phase coupling.

2.2 Definite time OCR with instantaneous element 2.3 Directional definite time OCR at SSP/SP 2.4 High speed tripping relays (master trip relay) 2.5 Panto flash over protection relay at

TSS/SSP/SP* as per clause (a) 9.8.5

(b) 9.8.6

2.6 Delta-I type fault selective relay 2.7 Logic based intelligent auto-recloser 3.0 Details for protection of capacitor bank

equipment (optional) –

640

* Note: Detailed requirement for its provision, communication media etc. shall be given in the tender as optional.

4.0 Relays for annunciation and D.C. supervision scheme

4.1 A set of aux. Relay necessary for annunciation (such as annunciation relay, flasher and bell relay etc.)

4.2 Aux. relay for d.c. supply supervision

4.3 Aux. Relay for d.c. fail alarm cancellation

4.4 Any other item(s) considered necessary by the purchaser or recommended by the tenderer for meeting the requirements of the scheme.

5.0 Test blocks with test plugs for testing the relays covered above against 1.0, 2.0, 3.0, 4.0, 5.0 & 6.0.

6.0 Notebook laptop Computer (Intel M 750 Centrino based 512 MB DDR, 80GB, CD/DVD/RW 14.1” TFT or latest) with required latest version of softwares/ waveform analyzing software with safe carrying cases.

7.0 HP DeskJet portable printer for printing the waveform data

8.0 Provision of fault locator in the relay.

9.0 Differential biased bus bar protections relay on HV side

10.0 High impedance type differential protection relay for bus bar on 25 kV side

11.0 Reverse power relay

641

642

Annexure7(1of3)

643

Annexure-(Sheet2of3)

644

Annexure-7(Sheet 3 of 3)

645

ANNEXURE-8

Addendum to RDSO Specification no. TI/SPC/PSI/PROTCT/4050 for Control & Relay Panel only for the purchase of MRVC work of Design, Supply , Erection, Testing

and Commissioning of 110 kV / 25 kV Traction Substation at Jogeshwari & 9 switching station in Mumbai Division of Western Railway at Mumbai (India)

Sr

No.

Reference

Clause

Page

1. 12.1

“Inspection &

Testing”

610 Wherever “RDSO” is appearing in the clause to be replaced

with “MRVC/RDSO”

2. 12.2

“Tests”

611 Wherever “RDSO” is appearing in the clause to be replaced

with “MRVC/RDSO”

3. 15.0

“Operation

Maintenance

Instruction &

Training”

615 (i) Wherever “RDSO” is appearing in the clause to be

replaced with “MRVC/RDSO”

(ii) Wherever “DG”(TI) RDSO” is appearing in the clause to

be replaced with “MRVC”

Documents

RESEARCH DESIGNS AND STANDARD ORGANISATION … SPEC(1).pdf · Control and Relay Panel for Protection System for 50 Hz AC traction substations parallel operation on 25 kV Side. TI/SPC/PSI/PROTCT/4050