Technical Spects

8/8/2019 Technical Spects

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ERECTION OF 33 KV LINE OVER VARIOUS TYPE OF POLES

1.0 SCOPE:

The works of erection of 33KV lines on 100% turnkey basis. The 33KV line is to

be erected on various type of poles with 100 Sq.mm AAA Conductor.

The scope covers the survey of the proposed route, tree clearance wherever

necessary, transport of material to the locations, erection of the line, testing of the

line and handing over to the A.P.E.P.D.C.L. as per specification.

2.0 GENERAL:

The contractor should be well acquainted with the I.E. Rules 1956 as amendedfrom time to time and with the Indian Telegraph Act 1889 so that the necessary

provisions therein may be followed.

3.0 SURVEY OF THE ROUTE:

The tentative route map of the line to be erected will be furnished by the

APEPDCL to he contractor along with the copy of the concluded agreement.

The contractor is required to carry out the detailed survey of the route of the line

and fix up the locations at the average span indicated in the schedule and mark the

locations and submit a detailed route map to the Engineer in charge of the workwithin 30 days for approval. In the course of surveying by the contractor, any

conspicuous variations in the change and physical feature to those indicated in

route map and as actually existing as noticed, the deviations must be brought tothe notice of the APEPDCLs Engineer. The APEPDCLs Engineer if considered

necessary shall make alterations to the route map and communicate the same to

the contractor in writing. As such alterations shall be carried out accordingly andthe APEPDCLs Engineer, after inspecting the surveyed route and the revisedroute map shall be given for final approval by the Engineer in charge in writing to

the contractor.

4.0 WAY LEAVES AND TREE CUTTINGS:

The contractor shall submit proposals for way leaves and right of way.Permission will be obtained by the APEPDCL within reasonable time for the

contractor shall give with due notices. The contractor shall arrange for tree

cuttings or tree branches cutting also.

The width of tree clearance to be adopted for the lines of various voltages is asdetailed below:

33 KV (trunk lines):

All growth within 6.096 M (20ft) from the centre line of support and all trees

which may fail and foul the line.

The contractor shall take all possible steps to see that standing crops etc., are notdamaged while attending to tree cutting. When such damage is inevitable the

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compensation will be borne by the APEPDCL provided the damage is with the

prior

concurrence of the Engineer. The contractor shall bear the compensation for

damage caused by the gangs without prior concurrence of the Engineer concerned.

No trees shall be cut until APEPDCL has made necessary arrangement with theauthorities concerned and permission is given to the contractor to cut such tree.

The contractor shall arrange to remove the obstacles as soon as possible.

At time however, it may not possible for the APEPDCL to arrange right-of-way

for excavation of pole pits or erecting the poles of stringing the line. At all such

times, the contractor shall shift his gangs to other areas. The rates quoted shallcover all such contingencies and no extra payments shall be claimed for such

contingencies.

5.0 EXCAVATION OF POLE /STAY/STRUT/ DP PITS:

After the final survey of the line and after marking the pole locations with pegs,

excavation work has to be commenced in accordance to the approved route map.Excavation is generally done by pick axes, crow V-bars and showers although

some times earth augers are used. Excavation of pole pits in very hard or rocky

soil or in rock beds may involve blasting of rock by suitable explosives. The pits

for the supports are excavated in the direction of the line as this will facilitate theerection of support, in addition to giving greater lateral stability, the depth of the

foundation to be excavated for pole shall be in accordance with relevant sketch for

the erection of pole or strut or D.P etc.

Excavation rates for poles, struts and D.P. pits shall be quoted by the contractor

for the following types of soil including dewatering of pits and shoring andshuttering wherever necessary. No quotation for extra rate for dewatering duringexcavation and shoring and shuttering will be entertained.

All soils other than hard rock.

Hard rock: Hard Rock will be that which requires drilling and blasting by any

method. The cost of drilling and blasting shall be included in the quoted rates. In

certain cases, when the area around the location happens to be an inhabited areaconsequent to which blasting cannot be restored to, the excavation may have, to

be dug with or by the process of drilling wedging, hammering and splitting or by

the process of heating and splitting by sudden cooling. The rate quoted shall takeinto consideration such contingencies also. Whenever blasting is resorted to, the

contractor shall make adequate arrangements of safety precautions. The

A.P.E.P.D.C.L. will not be responsible for any damages or accidents arising out ofprocess of blasting.

Note: For soils other than hard-rock excavation rate to be quoted shall include back

filling the pits with excavated soils after concreting wherever necessary.

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For soils covered by hard rock variety, the excavation rate shall be including back

filling with excavated rock bits and borrowed earth duly reamed after laying the

designed rock foundation.

No extra charges shall admissible for the removal of the fallen earth in the pit,

when once excavated.

The quoted rates should cover all contingencies during the process of excavation.

For any reasons what so ever, no extra claim will be accepted.

6.0 FOUNDATION:

Classification of Foundation:

Depending on the type of soils, the subsoil water table and the presence of surface

water, four types of foundation designs will be used for each locations classifiedin the following manner.

1) Wet type: To be used for locations:Where sub-soil waters is wet at 1.5 meters or more below the ground level.

Which are in surface water for long period with water generation not exceedingone meter below the ground level e.g. the paddy fields.

2) In black cotton soils.

a) Partially submerged type:

To be used at locations where sub-soils water table is met at more than 0.75

meters from the ground level.

b) Fully submerged type:

To be used at locations where sub-soil waters is met at less than 0.75 meters fromthe ground level.

3) Rocky type:

To be used at location where hard rock is met with and where the bond strengthbetween the rock and the concrete will be very high.

7.0 ERECTION OF SUPPORTS:

8.0Mtr poles as struts for 9.1 Mts PSCC Poles and 9.1 Mts PSCC Poles as struts

for Spun poles and 11 Mts PSCC Poles are to be used mostly and wherever

required stays also can be used.

After the excavation of pits is completed the supports to be erected may bebrought to the pit location. Then the pole may be erected inside the pit. Wooden

support may be utilized to facilitate lifting of the pole at the pit locations.

Before the pole is put into the pit, RCC padding may be laid below the pole to

increase the surface contact between the pole and the soil. The padding will

distribute the density of the pressure due to weight of the pole on the soil.

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Having lifted the pole, the same should be kept in a vertical position with the help

of manila rope of 25 mm dia. using the rope as a temporary anchor.

As the poles are being erected say from the pole already erected to the next

location where the pole is being erected the alignment of the poles are to be

checked and set right by visual check. The verticality of the poles is to bechecked with a spirit level on both transverse and longitudinal directions.

Having satisfied that the verticality and alignment are all right earth filling orconcreting is to be done.

In swampy and special locations, however, before earth filling, the poles are to be

concreted up-to ground level of the pit.After the poles have been set the temporary anchors are to be removed. The

supports shall be buried to a depth as per sketch enclosed.

8.0 ERECTION D.P STRUCTURES FOR ANGLE LOCATIONS ( 33KV LINES):

8ft (2440mm) line DPs for 33 KV are to be erected one for each Km and ABswitch on the DP are to be erected at angle points. One AB switch to be erected at

every 3 or 4 KM and depending on angle point as per field conditions and as per

the direction of the engineer.

Generally, for angles of deviation more than 200 double pole structures of spacing

8ft may be erected. The pits are to be excavated as per the bisection of the angleof deviation.

After the poles of DP are erected, the horizontal/cross bracings should be fitted

and the supports held in a vertical position with the help of temporary guys ofmanila rope at least 25 mm dia. Ensuring that the poles are held in a vertical

position (this can be checked with a spirit level) the concreting of the poles with

cement, granite chips of size 20/30 mm mesh and sand in the ratio M400conforming to ISS is to be done from the bottom of the support to the ground

level. Before lifting the pole in the pit, concrete padding of not less than 75 mm

thickness may be put for the distribution of the load of the support on the soil.

After the concreting is done, the pit may be filled with earth after the curing of the

concrete is completed.

Four stays/ or 2 struts & 2 stays along the line, two in each direction and twostay/struts along the bisection of the angle of deviation, are to be provided.

Stay/Strut concreting may be done with M 400 mixture.

The D. P. shall be erected as per the sketch enclosed.

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ANCHORING AND PROVIDING GUYS FOR SUPPORTS:

Guys are to be provided to the supports at the following places (I) Angle

locations, (ii) Dead and locations, (iii) Tee-off points, (iv) Steep gradient locationsto avoid uplift on the poles.

The installation of guy will involve the following works:

Excavation of pit and fixing of stay rod.

Fastening guy wire to the support.

Tightening guy wire and fastening to the anchor.

The marking of the guy pit for excavation, the excavation of pits and setting of the

anchor rod must be carefully carried out. The stay rod should be placed in theposition such that the angle of inclination of the rod with the vertical face of the

pit is as the case may be. The concreting of the stay at the bottom should then be

carried out. The back filling and ramming must be well done thereafter, andallowed to set for at least 7 days. Where the existence of guy wire proves

hazardous, it should be protected with suitable asbestos pipe, filled with concrete,of about 2Mtrs. length above the ground level, duly painted with white and black

stripes so that it may be visible at night. The turn buckle shall be mounted at thepole end of the stay and guy wire so fixed that the eye bolt turn buckle is half way

in the working position thus giving the maximum movement for tightening or

loosening.

Guy insulators are placed to prevent the lower part of the guy from becoming

electrically energized by a contact of the guy when the conductors snap and fall on

them or due to leakage. No guy insulator shall be located less than 2.6Mtrs. fromthe ground. The anchoring and providing guys for supports (Single guy Bow guy

an fly guy) shall be done as per sketch 3 enclosed. Bow guy and fly guy shallhave to be provided as per the field conditions.

FIXING OF CROSS ARMS AND INSULATORS

After the erection of supports and providing guys, the next step would be mountthe cross arms on the support. The cross arm is to be mounted after the support is

erected. The lineman should climb the support having requisite tools with him

and the cross arm is then tied to a hand line and pulled up by the ground man,through a pulley till the cross arm reaches the linemen. The ground man should

station himself well to one side so that if any material drops from the top of the

pole it may not strike him. All the materials required should be lifted or lowered

by means of the hand line. In no case, the material or the tools should be droppedor thrown from the pole top.

The fixing of 33 KV cross arms shall be in accordance to spacing detailed inSketch G.I. bolts and nuts and spring washers of good quality only shall be used

which have to be procured by the contractor.

Back Clamps:

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The back clamps for fixing of the V cross arms will have to be procured by the

contractor and shall be in accordance with sketch enclosed and the clamp shall be

fabricated with 75 X 8mm M.S.Flat for 33 KV line.

10.2 Top Cleats:

The top cleat shall be got fabricated with M.S. channel of 100x50mm and MS

angle of 65x65x6mm for 33 KV shall be in accordance with sketches enclosed.11. INSULATORS (AS PER IS 731)

The pins for insulators shall be fixed in the holes provided in the cross arms and

the pole top brackets. The insulators shall be mounted in their places over the pinsand tightened. In the case of strain or angle supports, where strain fittings are

provided for this purpose, on strap of the strain fittings is placed over the cross

arm before placing the bolts in the hole of the cross arms. The nut of straps is sotightened that the strap can move freely in horizontal direction, as this is necessary

to fix the strain insulator.

Note: The insulators shall be cleaned and examined for defects before fixing. It

shall be ensured that all the current carrying parts are smooth and without dirt,cracks or chips.

12.0 STRINGING OF THE LINE CONDUCTORS:

For the guidance of the contractor in handling the conductor and in stringing

certain Dos and Donts are given below, before the workmen actually commencethe stringing work.

12.1 Dos and Donts

Dos:

Use proper equipment for handling aluminum conductors at all times.

Use skids, or similar method for lowering reels or coils from transport or ground.

Examine reel before unreeling for presence of nails or any other object, whichmight damage the conductor.

Rotate the reel or coil while unwinding conductor.

Grip all strands while pulling out the conductor.Control the unreeling speed with a suitable braking arrangement.

Use wooden guards of suitable braking arrangement.

Use long straight, parallel jaw grip with suitable liners when pulling conductor

thus avoiding nicking or kinking of the conductor.Use free-running sleeves or blocks with adequate grooves for drawing/paving

conductors.

Use proper sag charts.

Mark conductors with crayons or adhesive tape of such (other) material which willnot damage the strand.

Make all splicing with the proper tools.Use a twisting wrench for twisting the joints.

Chromate or graphite conducting oxide-inhibiting grease should be applied before

cleaning with wire brush.

Donts:

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Do not handle conductors without proper tools at any stage.

Do not pull conductors without ensuring that there is no obstruction on the

ground.Do not pull out excess quantity of conductor than required.

Do not make jumper connections on dirty or weathered conductor. Clean the

conductor using sand paper or wire brush.Do not handle aluminum conductors in a rough fashion but handle it with care it

deserves.

Conductor Erections

The erection of overhead line conductor is a very important phase in construction.

The erection of conductors can be sub-divided into 4 separate parts as follows:

Transport of conductors to work site.

Paving and stringing of conductors.

Tensioning and sagging of conductors.

Jointing of conductors.

At important crossing of roads, canals, navigable rivers, railways etc., flagmen

should be in attendance to ensure that normal services are not unduly interrupted.These crossings should only be carried out in conjunction with and with the

approval of the proper authorities concerned.

The conductor drums shall be transported to the tension point without injuring theconductor. If, it is necessary to roll the drum on the ground for a small distance, it

should be slowly rolled in the direction of the arrow marked on the drum. The

drum should be so supported that it can be rotated freely. For this purpose thedrum should either be mounted on the cable drum supports or jacks or hung by

means of chain pulley of suitable capacity, suspended from a tripod. In case if it

is not possible to raise the conductor drum by any of the above methods, a trenchof suitable depth slightly bigger than the conductor drum may be dug, so as tofacilitate free rotations of the drum when it is suspended in the trench by means of

M.S. Shaft. While paving, care should be taken to see that conductor does not rub

against any metallic fitting of the pole or on the bad/rocky ground. Woodentussles should be used for this purpose to support the conductor.

The conductor should be passed over the poles on wooden or aluminum snatch

pulley blocks provided with low friction bearings. While conductor is beingpaved out slowly, some braking arrangements should be made so that the rotation

of the drum may be stopped in emergency.

In case the length of one piece of the conductor is less than the length of thesection in which conductor paving is being done, it is easy to stretch one length of

all phases from one end and the remaining length from another end of the section

and thereafter jointing the two ends of the conductor where they meet on noaccount any part of the conductor shall be left at a height of less than 5 meters.

Above the ground over night and the work shall be so arranged that before the end

of the day, the conductor shall be raised to minimum height of 5 meters above theground by rough sagging.

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12.3 Mid Span Jointing of Conductors:

The mid span jointing of conductors should be carried out by using 2Nos.aluminum ferrules of required size, one inner and one outer ferrule and the

crimping of the ferrules is to be done by using proper crimping tools. Aluminum

tape is to be wound over the conductor before insertion into the ferrules to have

better grip.

12.4 Sagging and Tensioning:

On the completion of the paving of the conductors and making mid-span joints ifany, tensioning operations will commence. Temporary stays will have to be

provided for both the anchoring supports in the section where the stringing has to

be done. At the tensioning end, one of the conductors is pulled manually up to acertain point and then come along clamp is fixed to the conductor to be tensioned.

The grip to the come along clamp is attached to double sleeve pulley block or the

pulley lift machine and gradually tensioned.

The conductor should then be sagged in accordance with the sag-temperaturechart for the particular conductor and span. The sag should then be adjusted in the

middle span of the section. The Engineer will provide the sag chart.

The stretch of the conductor has to be taken out before stringing in order to avoid

the gradual increase in sag due to the setting down of the individual wires. Thereare ways of accomplishing this.

12.5 Pre Stressing:

In this method the conductor is pulled up to a tension considerably above thecorrect figure, but never exceeding fifty percent of breaking load for a short period

of say twenty minutes. As this method requires more time and involves the use of

stronger tackle to secure the higher tension the other method of over-tensioning iscommonly adopted.

12.6 Over tensioning:

This method consists of pulling up the conductor to a tension a little above thetheoretical tension for the prevailing temperature and fixed it up at that tension

with correspondingly reduced sag. After a certain time the conductor will settle

down to the correct sag and tension. A tension of five to eight percent more thanthe theoretical value has been found to be suitable for the sizes of ACSR and

AAAC conductors standardized by REC. The ambient temperature during

sagging may be recorded correctly.

Conductors can be sagged correctly only when the tension is the same in each

span through out the entire length of the section. Use of snatch blocks reduces the

friction and chances of inequality of tension in various spans.

Sagging can be accomplished by several different methods but most commonly

used method is sighting. The sighting sag method of measuring sag is by theuse of targets placed on the supports below the cross arms. The targets may be

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light strip of wood clamped to the pole at a distance equal to the sag below the

conductor when the conductor is placed in snatch block. The lineman sees the sag

from the next pole. The tension of the conductor is then reduced or increased,until, the lowest part of the conductor in the span coincides with the linemans line

of sight.

When sagging is completed, the tension clamps shall be fixed. The clamp can be

fitted on the conductor without releasing the tension. A mark is made on the

conductor at a distance from the cross arms equal to the length of complete straininsulator. Before the insulator sets is raised to position, all nuts should be free.

Come along clamp is placed on the conductor beyond the conductor clamp and

attached to the pulling unit. The conductor is pulled insufficiently to allow the

insulator assembly to be fitted to the clamp. After the conductor is clamped toinsulator, assembly unit may be released gradually. If the tension is released with

a jerk, an abnormal stress may be transferred to conductor and support, which may

result in the failure of the cross arms, stay or pole in some cases. After the

stringing is completed, all poles, cross arms, insulators, fitting etc., are checked upto ensure that there have been no deformities etc.

The next step is to place the conductor on the top of the pin insulator from thesnatch block and removing snatch blocks. Conductors are then fastened to

insulator by the use of aluminum wires. The following points should be observed:

Proper size of the binding wire which can be readily handled and with adequate

strength to be used.

The length of tie wire should be sufficiently long for making complete tieincluding the end allowance for gripping with the ends.

A good tie should provide a secure binding between the line conductor andinsulator and should reinforce the conductor on either side of the insulator.

The use of cutting pliers for binding the site wire should be avoided.

The tie wire, which has been used, previously should not be re-used.

Before tieing the conductor to the insulator two layers of aluminum tape should be

wrapped over the conductor in the portion where it touches the insulator. Thewidth and thickness of aluminum tape to be used for a specific size of conductors

has been specified in handbooks of aluminum conductor manufactures and the

same may be preferred to. The aluminum tapes should also be used at the tensionclamp and for proper grip.

Normally in straight runs of line, the conductors are run on the top of insulators,

when there is small angle of deviation the conductor is placed inside groove andbinded. Accordingly, there are two methods of tieing the conductors to insulators.

The binding wire/tie wire has to be procured by the contractor and the bid price

shall include the cost of this.

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The contractor shall entirely responsible for any damage to the supports, other

accessories and conductor. He shall also be responsible for proper distribution of

the conductor drums to keep number and lengths of cut pieces of the conductor toa minimum.

12.7 Conductor damage and repair:

If the conductor is damaged for whatever reasons and damage is not repairedaluminum sleeves etc., it shall be brought to the notice of the Engineer and shall

not be used without his approval. Even repairing of conductor surfaces shall be

done only in case of minor damages, scuff marks etc. which are safe from bothelectrical and mechanical points of view. The final conductor surface shall be

clean, smooth, without any projections, sharp points, cut or abrasion etc., giving

satisfactory corona and R.I performance.

No joint or splice be made in spans crossing over main roads, railways, small

rivers or in tension spans. Not more than one joint per conductor shall be allowed

in one span. The strength of the joint shall confirm to I.E rule 75.

12.8 Stringing rate:

The stringing rate for stringing of the conductor per route length of line shallinclude paving, stringing, clamping, jointing, tensioning, strain disc binding,

clamping and fitting of all necessary accessories. Wherever necessary ground

clearance have to be measured to ensure obtaining adequate line clearance as per

I.E. rule 77 (I).

12.9 Jumpering

The jumpering at all locations where it is required i.e. cut points and tappingpoints etc. Should be done by using aluminum T-Clamps of suitable size required

for the conductor, and using aluminum tape over the conductor at the T-clamp

location to have a better grip. The bolts of the T-clamps should be tightened to therequired torque to prevent any loose contacts at the jumper locations.

13.0 EARTHING

Pipe Earthing:

At D.P. Location pits are to be excavated, the steel and metal parts are to be

earthed by pipe earthling as per the drawing of sketch enclosed to this

specification. Duly filling the pits with bentonite compound and black cotton soil(in1:6 ratio) and shall be maintained up-to a distance of 300 mm from the pipe in

all sides. The top edge of the pipe shall be at least 200 mm below the ground

level. The steel strips shall be fixed not less than 300 mm deep from the groundlevel.

The tenders shall quote the charges for earthing inclusive of the cost of bentonite

compound and block cotton soil, excavation and back-filling.

Pole Earthing :

All supports shall be properly earthed with coil earthing.

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The earthing of DP structures should be done in the presence of Asst. Divisional

Engineer/Construction only.

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13.3 CROSSINGS:

Guarding shall be erected as per standards and as per sketch a, b, c, enclosed forRailways, telephone lines and power lines.

13.4 Danger Boards

Danger boards of approved size shall be provided at places specified by engineer.

14.0 EXECUTION OF WORKS RELATING TO POWER LINE CROSSINGS

AND RAILWAY CROSSINGS:

Work such as erection of support underneath an existing power line and paving

out of conductors and earth-wire and stringing the power line crossing span or a

railway crossing span, will have to be done only after receipt of line clear form

APEPDCL authorities and approval from the concerned officer, which sometimes, may not match with program of the contractor. In such cases, the

contractor shall execute such works as and when approvals are received. His rates

for line erection and stringing shall take into consideration such contingenciesalso.

14.1 The railway crossing works involves following items

Item.No

Description of the Item Unit Quantity

1 Supply of 3x185Sqmm UG Cable of 33KV Line at VSEZ Mtr's 200

2 Supply of 250mm dia 5mm thick M.S.Pipe Mtr's 39

3 Supply of 125mm dia 3mm thick M.S.Pipe,2 Runs up to DP's Mtr's 84

4 Supply of 3x185Sqmm UG Cable jointing Kits (Heat shrinkable type) outdoor at VSEZ No's 4

5Supply & fixing of sign boards indicating 33KV crossing with concreteplinths at VSEZ

No's 2

6Erection of 250mm dia 5mm thick M.S.Pipe under the track by Boaringtechnique method with complete welding work for pipes as per railwaystandards.

Mtr's 39

7

Erection of 125mm dia 3mm thick M.S.Pipe out side the track to railwayboundaries under the depth of 2mtr's from original Ground level as perthe railway standards, and back filling after erection of MS Pipe and3X185Sqmm cable through pipes.

Mtr's 48

8Erection of 125mm dia 3mm thick M.S.Pipe and 3x185 Sqmm UGCable along the DP's Structure including Hard ware (i.e 100X50 mmMS channels, suitable MS clamps, Painting's to pipe's and channels,,Bolts& Nuts, etc) with concrete plinth base for each DP.

Mtr's 36

9Laying of Cable of size 185 Sqmm 3core under the track with boaringtechnique and out side from track to railway boundaries through 250mmdia pipe &125mm dia MS Pipes proportionately,

Mtr's 200

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10Erection of 4No's Out door type Heat shrikable Jointing kits of3x185Sqmm Cable at VSEZ

No's 4

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15.0 CONCRETING:

Note: All DP structures, Vertical formations, Single pole cut points, Angle

locations and all other Spun pole locations should be concreted.

The cement concrete used for the foundation shall be of ratio 1:3:6 using 40mm

HBG metal.

The sand used for the concrete shall be composed of hard silicon materials and

well sieved. It shall be clear and a sharp angular grit type of and free from earthy

or organic matter and deleterious salts.

The aggregate shall be of clean broken hard granite or other stone specified or

approved by the Engineer. It shall be hard, close grained quality. It shall also be

as far as possible cube like preferably angular, but not flaky, perfectly clean andfree from the earth organic or other deleterious matter, 40 mm aggregate shall be

of size as will pass through 40 mm square mesh measured in the clear.

The water used for mixing concrete shall be fresh and conform to ISI it should be

clean and free from oil, acids and alkali. Saltiest or brackish water should not beused.

The concrete should be mixed as stiff as the requirements of placing the concrete

in the forms or moulds with as and the degree to which the concrete resists

segregation will permit. Hence, the quantity of water used should not be toomuch.

Proper forms of moulds adequately braced to retain proper shape while concreting

should be used. The mould should be made watertight so that cement cream willnot come out leaving only sand and jelly consequently forming honeycombing in

the concrete. The rate for concrete should be made so that the works are not held

up on this account.

After concerting to the required height, the top surface should be finished smooth,

with slight slope towards the outer edge to drain off the rainwater falling on the

copings. These copings and muffing should be done after the stringing iscompleted in respect of tension locations and the Engineer at site may decide such

other locations as. For such locations an adhoc reduction of Rs.100/- per location

will be made while billing for concrete and this will be released after the copingand muffing are completed.

In wet locations, the site must be kept completely dewatered both during the

placing of the concrete and for 24 hours after completion. There should be no

disturbance of concrete by water during this period. No extra rate will be paid forthe dewatering and the rate for concrete shall be inclusive of dewatering charges.

The forms of moulds shall not be removed before a lapse of about 24 hours afterthe completion of concreting. After removal of the form moulds, the concreted

surface, wherever required, shall be repaired with a rich cement and sand motor in

the shortest possible time.

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The full concreting for the poles if erected in excavated pit shall be done so that

the complete block will be of the dimensions 0.6X0.6X1.5Mts up to ground level

including base concreting of 75mm thick with 1:3:6 CC mix.If augur is used for making pole pits, ramming shall be done after erection of

pole.

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16. WORKMANSHIP:

The contractor shall entirely be responsible for the correct erection of all supportas per the approved drawings, and their correct setting and alignment, as approved

by the Engineer. If the supports and D. P. structures after the erection are found to

differ from approved route maps and drawings or to be out of alignment, thecontractor shall dismantle and re-erect them correctly at his own cost without

extension of time. The supports must be truly vertical and in plumb after erection

and so straining will be permitted to bring them to vertical position. Verticality ofeach support shall be measured by the contractor and furnished to the Engineer.

17. Location numbers for each pole shall be painted on the pole.

Anti-climbing devices, and danger boards are to be provided at all railway

crossings and road crossings and DP locations. No extra charges shall beadmissible even though separate gangs may have to be sent by the contractor for

fitting these accessories and attachments on the support at the appropriate time.

18. FINAL CHECKING, TESTING AND COMMISSIONING

After the completion of the works final patrolling and checking of the line shall bedone by the contractor to ensure that all the foundation works, pole erection andstringing have been done as approved by the Engineer, and also to ensure that they

are complete in all respects. Contractor shall prepare pole schedules and hand it

over to the Engineer. All works shall be thoroughly inspected keeping in view of

the following main points.

i) Sufficient back filled earth is lying over each foundation pit and it is

adequately compacted.

ii) Concreting and coping of poles are in good and finally shaped conditions.iii) All the accessories and insulators are strictly as per the drawings and are

free from any defects or damages, what so ever.

iv) All the bolts and nuts should be hot dip G.I. material and as per contractualprovisions.

v) The stringing of the conductor has been done as per the approved sag and

desired clearances are available.

vi) No damage, minor or major to the conductor, earth wire, accessories andinsulator strings will unattended are noticed.

vii) For all points double jumpers shall be provided to each phase. The

jumpers provided at the cut points are connected rigidly to the tensionhardware utilizing all the jointing bolts provided for the purpose.

The contractor shall submit a report to the above effect to the Engineer. In case, it

is noticed later that some or any of the above are not fulfilled the engineer will getsuch items rectified through other agencies and recover the cost of such works

from the bills payable to the contractor against that contract or any other contract

executed by him for the APEPDCL

After final checking, the lines shall be tested for insulation in accordance with

tests prescribed by the Engineer. All arrangements for such testing or any othertest desired by the Engineer, shall be done by the contractor and necessary labour,

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transport and testing equipment shall be provided by him. The contractor defects

found out as a result of such tests, shall rectify any, forthwith, without any extra

charges to the APEPDCL

In addition to the above, the contractor shall be responsible for testing and

ensuring that the total and relative sags of the conductors are within the specified

tolerance. Such tests shall be carried out at selected points along the route asrequired by the Engineer and the contractor shall provide all necessary equipment

and labour to enable the test to be carried out. After satisfactory tests on the line

and approval by the Engineer the line shall be energized at full operating voltagebefore handling over.

19. Supply of materials by the contractor:

The contractor has to make his own arrangements for procurement, supply and useof materials and compliance of the following should be ensured.

These materials should conform to the relevant Indian Standard specification.

These materials shall be supplied at least one month in advance of their

requirement manufactures test certificate for these materials shall be submittedand got approved by Engineer before utilization. He shall guarantee the materials

so supplied by the contractor for satisfactory performance up to the end of themaintenance and defects liability period.

All materials to be supplied should fully conform to provisions under clause 3 ofInstructions to Bidders.

In procurement of these items the contractor shall follow all regulations of the

APEPDCL/Government of India in respect of import license etc., if he chooses toprocure these from imports. Further, the contractor shall be responsible for the

payment of applicable duties and taxes, port clearance inland transportation etc.

The materials for which advance is given by APEPDCL is to be insured by the

contractor at his cost from the date of payment of advance to the date stated in the

certificate of completion for the whole of the works.

Material & Quality:

All the material used in the works shall be of the best quality of their respective

kinds as specified herein. They shall be obtained from sources and suppliersapproved by the Engineer or his representatives, and shall comply strictly with the

tests, specified herein after or, where tests are not specified in this specification,

they should conform to the requirements of the latest issue of the relevant Indian

standards herein after abbreviated to as (I.S.) or other approved NationalStandards authorized by the Engineer. The contractor has got the obligation of

showing the proof of source of any material procured by him, to the APEPDCL on

demand.

Inspection and Testing:

Any materials used in the works shall be subject to inspection and tests if requiredby the Engineer. Unless otherwise stated, the costs of all tests required by this

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specification shall be deemed to be included in the rates and prices named by the

contractor in the bill (schedule) of quantities.

Any material, which is prepared or manufactured without notice having been

given in writing to the Engineer, may be rejected if the Engineer considers that his

inspection was necessary during the process of manufacture of such material.

Approvals: No material shall be used in the works unless the Engineer or his

representative has first approved it.

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20 INFORMATION AND DATA:

The information furnished is the best available however, the APEPDCL does not

guarantee the correctness or interpretations, deductions or conclusions which aregiven as supplementary information in the Bid Documents or in any reports, maps,

drawings, diagrams or in other reference information available to the bidder from

the APEPDCL of or otherwise.The information have been produced as found, communicated to ascertained or

otherwise learned by the APEPDCL

It will be the Bidders responsibility to satisfy himself from the ReferenceInformation supplied and/or inspection of the site that sufficient quantities of

construction materials required for the works shall exists in the designated borrow

areas or quarry sites.

The APEPDCL does not accept any responsibility either in handing over the

quarries or procuring the materials or any other facilities. The Tenders will not be

entitled for any extra rate or claim for the misjudgment on his part for the quantity

and quality of materials available in the quarries.

Failure by the Bidder to have done all the timings, which is in accordance withthis condition he is deemed to have done, shall not relieve the successful Bidder of

the responsibility for satisfactorily completing the works as required at the rates

quoted by him.

21 CONSTRUCTION MATERIALS

Cement:

The contractor has to make his own arrangements for the procurement of cementto required specifications required for the works subjected to the followings:

a) The contractor shall procure cement, required for the works only from reputedcement factories (Main producer) acceptable to the Engineer in-Charge. Thecontractor shall be required to furnish to the Engineer in-Charge bills of payment

and test certificates issued by the manufactures to authenticate procurement of

quality cement from the approved cement factory. The contractor shall make hisown arrangement for adequate storage of cement.

b) The contractor shall procure cement in standard packing of all 50Kg per

bag from the authorized manufacturers. The contractor shall make necessaryarrangement at his own cost to the satisfaction of Engineer-in-Charge for actual

weighment of random sample from the available stock and shall conform with the

specification laid down by the Indian Standard Institution or other standard

foreign institutions as the case may be, Cement shall be got tested for all the testsas directed by Engineer-in-Charge at-least one month in advance before the use of

cement bags brought and kept in site Godown.

The Contractor free of cost shall supply cement bags required for testing.

However, the testing charges for cement will be borne by the APEPDCL. If the

tests prove unsatisfactory, then the charges will be borne by the Contractor.

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c) The Contractor should store the cement of 60 days requirement at least one

month in advance to ensure the quality of cement so brought to site and shall not

remove the same without the written permission of the Engineer-in-Charge.

The Contractor shall forthwith remove from the works area any cement that the

Engineer-in-Charge may disallow for use, on account of failure to meet with

required quality and standard.

The contractor shall further, at all times satisfy the Engineer-in-charge on demand,

by production of records and books or by submission of returns and other proofs

as directed, that the cement is being used as tested and approved by Engineer-in-charge for the purpose and the Contractor shall at all times, keep his records up to

date enable the Engineer-in-charge to apply such checks as he may desire.

Cement which has been unduly long in storage with the Contractor or alternatively

has deteriorated due to in adequate storage and thus become unfit for use in the

works will be rejected by the department and no claim will be entertained. TheContractor shall forthwith remove from the work area, any cement the Engineer-

in-charge may disallow for use on work and replace it by cement complying withthe relevant Indian Standards.

22.0 STEEL:

The Contractor shall procure mild steel reinforcement bars, high yield strength

deformed (HYSD) bars, rods and structural steel etc., required for the works, onlyfrom the main or secondary producers manufacturing steel to the prescribed

specifications of Bureau of Indian Standard or equivalent and licensed to affix ISI

or other equivalent certifications marks and acceptable to the Engineer-in-Charge.

Necessary ISI list certificates are to be produced to Engineer-in-Charge before useon works. The unit weight and dimensions shall be as prescribed in the relevant

Indian standard specifications of steel. (AS PER IS 2062)

23.0 WASTAGE:

The contractor will be allowed for claiming additional quantities with the

following maximum additional quantities of materials to cover sag jumpering,wastage & losses etc., during erection of the line.

(i) Conductor a) Up to 1% of the route length for each of the conductors.

This % includes sag and jumpers.

b) Actual utilization of conductor for stiffness. Bridling

points in addition (as above)

Note: The Contractor has to follow R.E.C. standard for the works wherever it isnot specifically mentioned above.

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24. SPECIFICATION FOR ERECTION OF TOWERS

24. 1. TC Type Towers :

Fabrication and supply of TC type tower complete including struts, bolts and nuts,

cleats etc. Painting shall be with one coat of red oxide and two coats of alluninium paintof approved.

i) Excavation of pit including dewatering, planking, showing and shuttering

(wherever necessary) and leveling in all types of soils such as BC, red earth hardgravely etc in all conditions

ii) Erection of tower parts completely as per specifications including erection ofinsulators with all accessories jumpering transport of material and painting of tower

with two coats of alluninium paint and bolts and nuts etc

iii) CC 1:3:6 with 40 mm HBG metal for foundations including cost of all concreting

materials and cement and curing for 14 days.

iv) Tack welding of bolts and nuts up to the first leg each bolt at three sports including

cost of electrodes and electricity.

v) Pipe earthing of towers with 40 mm dia GI pipe and GI earth of size mm x 4 mm

including cost of pipe bentonite power and running of GI flat etc.

24. 2. TD Type Towers :

Fabrication and supply of TD type tower complete including struts, bolts and nuts,cleats etc. Painting shall be with one coat of red oxide and two coats of alluninium paint

of approved.

i) Excavation of pit including dewatering, planking, showing and shuttering(wherever necessary) and leveling in all types of soils such as BC, red earth hard

gravely etc in all conditions

ii) Erection of tower parts completely as per specifications including erection ofinsulators with all accessories jumpering transport of material and painting of tower

with two coats of alluninium paint and bolts and nuts etc

iii) CC 1:3:6 with 40 mm HBG metal for foundations including cost of all concretingmaterials and cement and curing for 14 days.





24.3 BD Type Towers :

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Fabrication and supply of TD type tower complete including struts, bolts and nuts,

cleats etc. Painting shall be with one coat of red oxide and two coats of alluninium paint

of approved.

i) Erection of tower parts completely as per specifications including erection of

insulators with all accessories jumpering transport of material and painting of towerwith two

coats of alluninium paint and bolts and nuts etc.

ii) Tack welding of bolts and nuts up to the first leg each bolt at three sportsincluding cost of electrodes and electricity.

24. 4. M+12 Type Towers :

Fabrication supply and erection of M+12 type tower with GI angles in full shape with

all accessories, bolts and nuts (with GI) tightening, measuring tower vertically includingbolts and nuts and conveyance of all to site including laying of RCC 1:2:4 for base and

colums concreting with 12 to 20 HBG metal with double circuit provision and to usesuspension insulators.(2.520 MT/Tower)


(wherever necessary) and leveling in all types of soils such as BC, red earth hard

gravely etc in all conditions.

ii) Erection of tower parts completely as per the direction of engineer incharge

including erection of suspension insulators with all accessories jumpering transport

of material and painting of tower with two coats of alluninium paint and bolts andnuts etc.

iii) CC 1:2:4 with 12 to 20 mm HBG metal for foundations including cost of allconcreting materials and cement and curing for 14 days.





24. 5 M+8 Type Towers :

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Fabrication of supply of M+8 type tower complete including struts, bolts and nuts,

cleats etc. Painting shall be with one coat of red oxide and two cots of alluninium paint of

approved quality.


(wherever necessary) and leveling in all types of soils such as BC, red earth hardgravely etc in all conditions.

ii) Erection of tower parts completely as per specifications including erection of

insulators with all accessories jumpering transport of material and painting of towerwith two coats of alluninium paint and bolts and nuts etc.

iii) CC 1:3:6 with 40 mm HBG metal for foundations including cost of all concreting

materials and cement and curing for 14 days.





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25/74

such standards with authentic English Translations, shall be furnished along with

the offer. In case of conflict the order of precedence shall be (i) IS (ii) IEC (iii)

Other standards. In case of any difference between provisions of these standardsand provisions of this specification, the provisions contained in this specification

shall prevail.

3.0 CLIMATIC CONDITIONS:

The Vacuum Circuit Breakers to be supplied against this Specification shall be

suitable for satisfactory continuous operation under the following climaticconditions.

Sl.

No.

Location At various locations in the

state of Andhra Pradesh

i) Max. ambient air temperature (deg.C) 50

ii) Min. ambient air temperature (deg.C) 7.5

iii) Average daily ambient air temperature (deg.C) 35

iv) Max. Relative Humidity (%) 100

v) Max. altitude above mean sea level (Meters) 1000

vi) Average Annual rainfall (mm). 925

vii) Max. wind pressure(kg/sq.m.) 200

viii) Isoceraunic level (days per year) 50

ix) Seismic level (Horizontal accn.) 0.3 g.

The equipment shall be for use in moderately hot and humid tropical climate,

conducive to rust and fungus growth.

4.0 PRINCIPAL PARAMETERS:

4.1 CIRCUIT BERAKERS: 33 KV

Service Out door

Type Vacuum Porcelain clad (Outdoor)

No. of Poles/Phases Three

Rated Voltage (Nominal/Max.) 33/36KV

Rated frequency 50 Hz

System of earthing Neutral solidly grounded

Impulse withstand Voltage 170 KVp

Power frequency withstand voltage for 1min 75KV(rms)

Power frequency withstandvoltage on Auxiliary circuit: 2 KV(rms)

Rated Current 1250 A

Rated breaking Capacity Symmetrical 25 KA

Rated short time withstand current for 3 sec 25 KA

Rating making capacity 2.55 times Rated breaking Current

Total break time 5 Cycles(max)

Bushing Insulator creepage distance Not less than 900mm

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Mounting Steel Structure

Operating duty for gang operation. O-0.3 sec.-CO-3 min.-CO.

Operating Mechanism Motor operated/Manual spring charged. Thestandard DC voltage for the operating devices

shall be 220V DC. Operation Voltage for

motor spring charging mechanism shall be 220V AC single phase. Normally the breaker shall

be operated by power and there shall be

provision for manual operation. Provision shall

be made for slow closing of VCB withoutspring charging.

Terminal connector Material (for outdoor) Aluminium suitable for 420 Sqmm conductor

Limits of temperature rise The limits of temperature rise shall be in

accordance with relevant standard (IEC 62271)

Requirement of simultaneity of poles The maximum difference between instants of

contact touching during closing and the

maximum difference between the instant ofcontacts separation during opening between 3

poles shall not exceed one half cycle of the

rated frequency. The breaker shall open andclose simultaneously on all the three phases for

fault on any phase and or on all the phases

Protection The Breakers shall be provided with 3 Over

current (3O/L) and one Earth fault (1 E/L)IDMT relay with min. 5% setting with high set

Instantaneous elements. 2Nos. 220V DC

auxiliary relays are to be provided for powertransformer protection with 2NO+2 NC

contacts & Hand reset type for LV control

VCBs having CTs of ratio 200-100/1-1-1A.

Pad locking for both mechanism box, control

panel should be provided

Pad locking for both mechanism box, control

panel should be provided

All angles 65 mm X 65 mm X 6 mm

minimum size for breaker structure should be

provided

All angles 65 mm X 65 mm X 6 mm minimum

size for breaker structure should be provided

Bell is operated 220 V DC Bell is operated 220 V DC

Note: The relays shall be numerical relays of Alstrom / ABB / ER / L&T makes with

IDMT (Inverse Definite Minimum Time) characteristics and also with high set

instantaneous elements for high fault currents and shall comply with relevantstandard. The accuracy class of relays shall be clearly specified as per IS.

4.2 Auxiliary Electrical equipment shall be suitable for operation on the following

supply system.

Power devices (drive motors) and lighting240V single phase-4 wire 50c/s. andlighting neutral grounded AC supply.

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28/74

the breaker rupturing capacity and

duration to suit the maximum trippingtime.

Accuracy limit factor 10 for protective core

ISF


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5.2.1 GENERAL ARRANGEMENTS:

The circuit breaker shall have fixed type construction consisting three singleidentical poles, complete with a gang operated sealed porcelain housing

conforming to IP-65 protection conforming to relevant standards. All three poles

of circuit breaker shall be linked together electrically/mechanically to ensure

simultaneous closing of all poles.

The trip free operating mechanism, 3 phases inter connection links shall be

completely accommodated in the base. There shall be sufficient clearancebetween live parts of the circuit breakers and the ground. The circuit breaker shall

be completed with operating mechanism, other accessories/materials to ensure

complete assembly and proper functioning. The current transformers shall beexternally mounted on the supporting structure integrated with circuit Breaker

structure. Terminal connectors suitable for Panther conductor should be supplied

for Circuit Breakers and Current Transformers. The circuit breaker shall be

provided with proper standard earthing and with terminal earth bar for earthing

connection. Suitable inter - connection between Circuit Breaker terminals andCurrent Transformer Terminals are to be provided.

Note : Neither the circuit breaker nor any part of the switchgear or its supporting

structures shall be permanently strained due to vibration etc., when making or

breaking the rated short circuit currents.

The details of any device incorporated in the circuit breakers to limit or control the

rate of restriking voltage across the circuit breaking contacts shall be stated.

The vacuum interrupter assembly used in the circuit breakers shall be

interchangeable with indigenously available vacuum interrupters (make and type

shall be mentioned).

5.2.2 MAIN CONTACTS AND ARC QUENCHING CHAMBER:

The main contacts shall have adequate area and contact pressure for carrying ratedcontinuous and short time currents without excessive heating liable to cause

pitting and welding.

The tips of the arcing & main contacts shall be heavily silver plated.

The contacts that are adjustable to allow for wear, shall be easily replaceable and

shall have minimum moveable part and adjustments. The arc-quenching device

shall be of robust construction and shall not require any critical adjustments. Thedevices shall be easily accessible and removable for access to the breaker

contacts.

5.2.3 INTERLOCK:

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All electrical and mechanical interlocks, which are necessary for safe and

satisfactory operation of the circuit breaker, shall be furnished. It is intended that

before lockout occurs the breaker shall be in trip position.

5.2.4 AUXILIARY CONTACTS:

Each breaker shall be provided with Four (4) normally open and Four (4)

normally closed electrically separate spare Auxiliary contacts in addition to those

required for its own operation and indication exclusively for Employers use.

The auxiliary contacts shall be convertible type so that normally open contacts can

be converted into normally close contact and vice verse at site.

The auxiliary contacts shall be rated for 10A for AC and 5A for DC

5.2.5 INSULATORS:

Bushing insulator for circuit Breakers shall comply wherever possible with

relevant standard for High voltage porcelain bushings.

Insulators shall be wet process porcelain, brown glazed and free from all

blemishes. Ferrous metal parts and hardware shall be hot-dip galvanised.

Insulator shall have adequate mechanical strength and rigidity to withstand the

duty involved.

When operated at maximum system voltage there shall be no electrical discharge.

Shielding rings, if necessary, shall be provided. Insulation shall be coordinated

with basic impulse level of the system. The creepage distance shall correspond toheavily polluted atmosphere.

5.3 OPERATING MECHANISM:

The operating mechanism shall be motor operated/ manual operated spring closing

with trip free features complete with shunt trip coils. All three poles of the

breaker shall operate simultaneously, It shall operate in such a way that theclosing springs after each closing operation are automatically charged by the

motor and locked in the charged position by a latch. Means shall be provided to

charge the springs manually also. Provision shall be made for slow closing of

VCB without spring charging. The springs shall get changed within appropriatetime to facilitate auto-reclosing operations.

The mechanism to be operated for the reclosing operations should the circuit

breaker trip. The contact loading spring shall be designed in such a way that the

contact bounce is eliminated and it shall be ensured and the opening stroke is

commenced only from fully closed position. All the breakers shall be suitable for

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manual operation as well as slow closing without spring charging. Anti pumping

device shall be incorporated.

Operation counter and mechanically operated indicator to show whether the

circuit breaker is open or closed shall be provided on the circuit breaker operating

mechanism.

All manually operating gear shall be so designed that the circuit breaker can be

operated by one movement. The mechanism shall be such that the tripping springcan be charged while the circuit breaker is closed and the closing mechanism

when charged shall not be operated by vibration caused by the circuit breaker

opening under fault conditions. The spring shall be suitable for 4 short reclosing

operations.

The mechanism shall be designed for electrical control from remote. Local

manual close/trip (lever/button) shall be provided in the mechanism box.

5.4 CONTROL CUBICLE (MECHANISM BOX) FOR OUTDOOR VCBS:

A common control cubicle shall be furnished to house electrical controls,monitoring devices and all other accessories except those, which must be located

on individual poles.

The cubicle shall have IP-55 of gasketed whether proof construction, fabricated

from sheet steel minimum 2.5 mm thick.

The cubicle shall have front access door with lock and keys, and removable glandplate at the bottom for cable entry.

5.5 WIRING & TERMINAL BLOCKS:

5.5.1 WIRING:

Wiring shall be complete in all respects to ensure proper functioning of thecontrol, protection, monitoring and interlocking schemes.

Wiring shall be done with flexible 1100 V grade, PVC insulated, switchboardwires with 2.5 sq.mm stranded copper conductor, and Wiring between individual

poles and control cubicle shall be routed through G.I Conduits.

Each wire shall be identified at both ends with permanent markers bearing wirenumbers as per wiring diagram. The wiring schematic may conform to relevant

standards.

Wire termination shall be done with crimping type connectors with insulatingsleeves. Wires shall be spliced between terminals.

All spare contacts of relays, push buttons auxiliary switches etc. shall be wiredupto terminal blocks in the control cubicle.

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5.5.2 TERMINAL BLOCKS:

Terminal blocks shall be 1100 V grade, box clamp type (Stud type).

Not more than two wires shall be connected to any terminal Spare terminals equal

in number to 20% active terminal shall be furnished.

Terminal blocks shall be located to allow easy access. Wiring shall be so

arranged that individual wires of an external cable can be connected toconstructive terminals.

5.6 NAME /RATING PLATE:

CIRCUIT BREAKERS : Each circuit-breaker shall be provided with a name

plate or plates legibly and indelibly marked with atleast the following

information :

a) Name of manufacturer b) Type designation and serial number

c) Rated voltage and current.d) Rated frequency

e) Rated symmetrical breaking capacity

f) Rated making capacity andg) Rated short-time current and its duration (which shall be either one or

three seconds)

h) P.O No. & Date and year of supply

Note: The word Rated need not appear on the nameplate recognized

abbreviations may be used to express the above quantities.When the circuit breaker is fitted with closing and/or tripping devicesnecessitating an auxiliary supply the nature of the auxiliary supply shall be stated

either on the circuit breaker nameplate or in any other acceptable position.

The words APEPDCL must be etched on the nameplate.

5.7 CONTROL & RELAY PANELS:

5.7.1 CONSTRUCTION:

The Control Panels to house meters, relays and other items as specified in Cl.5.8.3. shall be weather proof and vermin proof and of rust-free pressed steel

cubicle type with hinged door and locking device. Ventilation louvers shall be

provided with GI mesh. The frame shall be made of angle iron or structural steelof sufficient weight and strength to ensure permanent rigidity and alignment. The

control panel shall be provided with inter connections, small wiring leads,

terminal bolts, fuses, earth bar, multi core cable glands, earth connections etc.

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The panel should be provided with locking handle with built-in-door lock and the

lock shall be provided with duplicate keys.

The outdoor panels shall be preferably of the following dimensions:

Height 1750 mm, from plinth level to live part.

Width 500mmDepth to be adjusted to accommodate relays & relays instruments but not less

than 500mm.

The exterior of the panels shall be epoxy painted with dark admiral Grey colour

and interior should be painted with half white colour. The panel shall be provided

with MCBs for AC circuit fuse units for potential Circuit (potential coilconnections to static trivector meters etc.) and DC control circuit, Indication

circuit etc. The internal wiring of the panels shall be with 2.5 Sq.mm 1100V

grade standard copper PVC insulated wiring of reputed make.

The thickness of the sheet steel for the front of the panels (where the meters etc.are fixed) and supporting members of the panels shall be of 3mm and for the other

members of the panel sheet steel thickness shall be 2mm.

Wherever control panels are fixed to the breaker structure necessary clearance

from the ground to read the meters and to operate the switches shall bemaintained. The cables from circuit breakers and current transformers to control

panels shall be provided.

5.7.2 PAINTING:

Before painting all ungalvansied parts shall be completely cleaned and made freeof rust, scale and grease and all external rough surface cavities on casting shall befilled by metal deposition.

The interior parts and internal structural steel work shall be cleaned of all scaleand rust by sand blasting and given a primary coat and two coats of oil and

weather resisting epoxy paint.

All external surfaces shall receive a minimum of 3 coats of paint. The paint shall

be guaranteed for 5 years from the date of receipt of material.

5.7.3 CURRENT TRANSFORMERS

5.7.3.1 Construction:The core shall be high-grade non-aging electrical silicon-laminated steel of lowhysterisis loss and high permeability to ensure high accuracy, at both normal and

over current.

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The secondary terminals shall be brought into a compartment on one side of

current transformer for easy access. The secondary terminals shall be provided

with short circuiting arrangements. The secondary taps shall be adequatelyreinforced to withstand normal handling without damage.

The current transformer shall be suitable for mounting on steel structure orconcrete pedestals. The necessary flanges, bolts, etc for the base of current

transformer shall be supplied and these shall be galvanized. The current

transformer tank and other metal parts shall be galvanized.

The various ratios of Current Transformers shall be obtained by changing the

effective number of turns on the secondary. The magnetization curves for

secondary cores shall be invariably furnished with the tender specifically markingthe point on the curve at which knee point voltage is obtainable and also the

corresponding excitation current. The secondary terminals shall be adequately

reinforced to withstand normal handling without damage. The current

transformers shall be designed to carry continuously a current of at least 125% ofthe rated current.

All windings of Current Transformers shall be made of double paper covering

insulation and the manufacturing of the units shall be done in completely closed

and air-conditioned room. Fiberglass insulation sleeves are to be provided for

primary winding. Details of winding and core shall be furnished.

The current transformers shall be complete in all respect with filling of oil

confirming to IS:335 and with oil level indicator with minimum/maximum oillevels.

5.7.4 NAME/RATING PLATE:

Each Current Transformer/Potential Transformer shall have the following

particulars indelibly marked on it or on a label permanently secured to it or itscasing.

a) Manufacturers Name

b) Manufacturers Sl.No. and/or type of designation.c) Rated transformation ratio

d) Rated frequency

e) Highest system voltage

f) Insulation level andg) Rated short time thermal current with the associated rated time and rated

dynamic current for CTs.

The purchase order number and date and year of supply and the words APEPDCL

must be etched on the nameplate.

5.8 SCHEDULE OF EQUIPMENT:

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5.8.1 CIRCUIT BREAKERS:

The Circuit breaker complete with suitable epoxy painted steel support structure

(with anchor bolts & nuts) for outdoor shall have 1 No. Vacuum Circuit Breaker -

3 poles, Mechanism box, control and relay panels and current transformers.

Note: -Earth strips as per relevant Standards shall be provided for proper earthing of

equipment.

-Earth bar of copper (suitable for termination of 2 Nos. 50 x 6 mm Flats) shall beprovided on Circuit breaker support structure.

-Connecting cable from breaker to control panel and breaker to CT are to be

provided.-For HV/LV breakers, collecting cable from breaker to CTs 6 core cable of 5 m

length from each CT i.e., total 3 x 5 = 15 m. Breaker and from Breaker to control

panel 10 core cable of 10 m length.

-Size of control cable is 2.5 Sqmm (armourded stranded copper cable)

-Metallic sealing bellows are to be provided at the bottom of the all poleassemblies.

5.8.2 MECHANISM BOX CONTAINING:

a) Operating mechanism

b) Mechanical indicator for ON and OFF coupled to the circuitbreaker operating mechanism.

c) Mechanical close and trip ( with protective flap ) lever/push button.

d) Terminal blocks for control wiring and a spare terminal block (with 20%of he active terminals).

e) Operation Counter.

f) Operating handle for manual charging of springs.g) 2 Nos. cable glands over and above those provided for control cables with

suitable dummies.

h) Not less than four numbers normally open and four numbers normally

close spare auxiliary contacts over and above those required for normaloperation.

i) 230V single phase AC Motor / Manual operated spring charging

mechanism complete with electrical spring release coil, 2Nos. shunttrip coils and 1 No. closing coil.

j) Local - Remote selector switch.

k) Earth bar ( suitable for termination of 2 Nos. 50 X 6mm class )

l) 6 Nos. Terminal connectors for incoming and outgoing connectors foroutdoor VCB.

m) Set of 2 poles MCBs for AC and DC supply with different colours.

n) 1 No. EE/ABB/Jyothi make Anti-pumping relay

5.8.3 CONTROL AND RELAY PANEL FOR 33KV VCB:

Weather proof, vermin proof control and relay panel mounted on the breaker

structure having equipped as follows:

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a) 3 Digit LED display CT Operated digital AC Ammeter to suit the CT

ranges indicated in Section IV. (Schedule of materials) shall be AE/IMP make.b) One ammeter selector switch with R, Y, B, Neutral and OFF

positions.

c) One Heavy duty pistol grip type control switch for VCB trip/Neutral/Close

positions with spring return to neutral position.d) One Red and one Green indicating lamps for indicating Close and Open

positions respectively.

e) One yellow Lamp for healthy trip indication with push button control.f) One white lamp for spring charged indication.

g) One amber lamp for auto-trip indication.

h) Numerical relays shall be EE make/ABB make/ER make/ L&T make withthe following features.

i) IDMT relays with 3 poles arranged for O/L and one pole for E/L with min.

5% setting.

j) Two Nos. cable glands over and above those provided for control CT and PT

cables, control circuit cables and auxiliary supplies (AC & DC) with suitabledummies.

k) 3 Digit LED display digital AC volt meter with selector switch for 33KVcircuit breakers One set alarm bell and push button for acceptance of alarm.

l) 2 Nos. AC & DC MCBs for control circuit. Set of fine wiring with ferrules

with standard code number of respective terminals and with suitable terminal connectors.m) 240V three pin socket with plug & switch

n) Test terminal block with CT and PT terminals with links for testing ammeter

and static trivector meter.o) Stud terminal blocks (Bolt and nut type) for CT and PT control cables suitably

wired with 6Nos. spare terminals.

p) One suitable copper earth strip of 12x3 mm size with adequate number of holes with suitable nuts and bolts for outdoor VCB.

q) For 33KV VCBs provision for mounting the static trivector meter of standard

size, flush of panel type shall be made. The meter will be provided by the Employer at

the time of erection.r) Additional locking arrangement to the panel door to be provided.

s) One suitable copper earth strip of 12x3mm size with adequate number of

holes with suitable nuts and bolts for outdoor VCB.

Note: All the instruments and relays to be provided on control panel shall be flush

mounted. The relays are to be worked on one amp secondary current of Current

Transformers and with DC voltage of 24V.The current and potential transformers shall be mounted in such a manner that

their secondary terminal connections are accessible for testing and maintenance

purposes. --The terminals for CTs shall be provided with shorting links.-All indicating lamps are of extended LED type only.

-1 No. push button for trip circuit for healthy check up

-1 No. plug point with switch (10 A, 230 V AC)-1 No. Illuminator lamp with switch (40W, 230 VAC)

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-1 No. panel space heater with heater switch thermostat

-Complete wiring is to be done with ring type copper lugs with proper crimping.

5.8.4 CURRENT TRANSFORMERS:

Three numbers Current Transformers as specified.

Terminal connectors suitable for Panther conductor for 33KV shall be

supplied for Circuit Breaker (6Nos.) and CT Terminals (6Nos.). Suitable inter

connection between circuit breaker terminals and CT terminals are to be providedfor outdoor VCBs. Terminal connectors should have contact area of above 300

Sq.mm when connected to VCB & CTs and must be bushing type.

Note: Other standard accessories which are not specifically mentioned but supplied withbreakers of similar type and rating for efficient and trouble free operation shall be

provided.

Special Guarantee: The vacuum bottles shall be guaranteed for satisfactoryoperation for

period of five years from the date of commissioning, including vacuum bottlesmechanism box and all bushings etc.

Guaranteed Technical Particulars: The bidder shall indicate the technical particulars

guaranteed in the proforma given in Annexures. I(A) & I(B).

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6.0 TESTS:

6.1 The type, acceptance and routine tests and tests during manufacture, shall becarried out on the vacuum circuit breaker as per the IEC 62271-100 -2001 and

current transformers as per IS 2705 (with latest revision).

6.1.1 The standards and norms to which these tests will be carried out are listed in

ISS/IEC mentioned above.

6.1.2 For all type and acceptance tests, the acceptance values shall be the values

guaranteed by the supplier in the proforma for Guaranteed Technical Particulars

furnished in this specification or acceptance value specified in this specification,whichever is more stringent for that particular test.

6.1.3 Test certificate of not more than three years old, from a recognized nationallaboratory with NABL accreditation shall be furnished.

6.2 TYPE TESTS:

The circuit breakers and current transformers shall be fully type tested by the bidder

as per the relevant standard including the type tests mentioned below in Cl. 6.2.1 &6.2.2. The type tests must have been conducted on 33KV Vacuum Circuit Breakers

and current transformers from recognized NABL accredited test laboratories. Thedate of type tests will not be later than 10 years and to add at end if any change in

design as made latest type tests shall be furnished along with approved drawing.

BIDS WITHOUT THE FOLLOWING TYPE TEST REPORTS WILL BE TREATED AS NON-

RESPONSIVE.

6.2.1 CIRCUIT BREAKERS: IS13118/IEC62271

a) Temperature rise test for the main circuits.

b) Measurement of resistance of the main circuit.c) Operation tests.

d) Mechanical endurance tests.

e) Impulse voltage tests.f) One minute power frequency voltage dry withstand tests.

g) One minute power frequency voltage wet withstand tests.

h) Tests for short circuit conditions.i) Tests for short time current.

6.2.2 CURRENT TRANSFORMERS: IS 2705

a) Verification of terminal markings and polarity. b) High voltage power frequency test on primary windings.

c) High voltage power frequency test on secondary windings.

d) Over voltage inter-turn test.e) Determination of error according to the requirements of appropriate

accuracy class.

f) Short-time currentg) Temperature rise test.

h) Impulse voltage test for current transformers for services in electrically

exposed installations.

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6.2.3 ACCEPTANCE AND ROUTINE TESTS :

6.2.3.1CIRCUIT BREAKERS:

a) Measurement of resistance of the main circuits.

b) Operation tests.

c) One minute power frequency voltage dry withstand test on thecircuit

breakers

d) One minute power frequency voltage dry withstand test on auxiliary

circuits.

6.2.3.2 CURRENT TRANSFORMERS:

a) Verification of terminal markings and polarity.

b) High voltage power frequency test on primary windings.c) High voltage power frequency test on secondary windings.

d) Over voltage inter-turn test.e) Determination of error according to the requirements of appropriate

accuracy class.

All acceptance and routine tests stipulated in the relevant standards shall be

carried out by the supplier in presence of Employers representative.

The employer reserves the right to insist for witnessing the acceptance/routine

testing of the bought out items to pass tests.

6.2.3.3Tests during manufacture: The Bidder shall furnish details of tests carried out

during the process of manufacture and end inspection by the bidder to ensure the

desired quality of the equipment to be supplied.

6.3 ADDITIONAL TESTS:

6.3.1 The Employer reserves the right of having at his own expenses any other tests(s) of

reasonable nature carried out at Bidders premises, at site, or in any other place in

addition to the aforesaid type, acceptance and routine tests, to satisfy himself that the

material comply with the specifications.

6.3.2 In case of failure in any type test, the supplier is required to modify the design of the

material and the material shall be type tested again for the modified design, withoutany extra cost to the Employer. No delivery extension shall be given for this

additional testing.

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6.3.3 The entire cost of testing for the acceptance and routine tests and tests during

manufacture shall be treated as included in the quoted unit price.

6.4 TEST REPORTS / TEST CERTIFICATES:

6.4.1 Record of routine test reports shall be maintained by the Bidder at his works forperiodic

inspection by the Employers representative.

The Bidder shall maintain test certificates of tests conducted during manufacture.These shall be produced for verification as and when desired by the Employer.

6.5 TEST FACILITIES :

The tests shall be carried out as per relevant Standards and test certificates shall be

furnished for approval. The Bidder shall indicate the details of the equipment available

with him for carrying out the various tests as per relevant Standards. The bidder shall

indicate the sources of all materials. He shall indicate the name of the supplier and make

of vacuum interrupters, meters, relays, conductor, insulating oil, electrical steel

laminations constructional steel etc.

NOTE :- The Meters used for conducting tests shall be calibrated periodically at reputedGovernment Accredited Test Laboratories and test certificates shall be available at works for

verification by Employer representative.

9. MANDATORY SPARES & TOOLS:

The manufacturer shall provide all necessary mandatory spares like fuses, spanners, etc.,free of cost.

10. TECHNICAL DEVIATIONS:

Any deviation in Technical Specification as indicated in Section-III shall be specifically

and clearly indicated in the enclosed Technical deviation format as per Annexure II or

in the schedule of deviation format Schedule A.

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11. GUARANTEED TECHNICAL PARTICULARS

The Bidder shall furnish the guaranteed Technical Particulars as per Annexure I,enclosed and submit the same with the Tender.

ANNEXURE IGUARANTEED TECHNICAL PARTICULARS FOR AIR BREAK SWITCHES

Sl.No DetailsGuaranteedparticulars

Air Break Switches (Isolators) 33 KV

800 A

A Name(s) of Manufacturer(s)B Whether single break or double break

C No. of poles

d Voltage rating

e Frequencyf Current rating in Amps.

i. Normalii. Max. with duration

g Temperature rise of the following at full rated

current in Deg. C over ambient temperature

i. Copper contacts with coatingii. Terminal of switches intended to be bolted to the

external conductors

h Whether contracts are silver coated or t in coatedalong with thickness of coating in mm

i Voltage drop across terminals of poles

j Short time current and durationk Material of fixed contact

l Material of moving blade

m Material of terminal connectorn Type, diameter and length of operating handle

o Material of arcing horns

p Size and length of mounting channel

q Whether the Air break switch is complete with allaccessories

r Whether dimensional drawing is enclosed with the

bids Minimum clearance between phases (The centre

distance between the insulators of adjacent phases in

assembled position of switch)T Centre to centre distance between insulators of the

constructive poles of the same phase in the

assembled position of switch (in mm)

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Sl.No DetailsGuaranteed

particulars

U Whether mechanical interlock has been provided forEARTH Switches

33 KV, 800 A

V Type of bearings used in

i. Rotating insulator stackii. Operating shaft

W Impulses withstand voltage with 1/50 Micro Sec.

wave positive and negative polarityi. Across isolating distance

ii. To each and between poles

X One minute power frequency withstand voltage

across isolating distance to earth and between poles2 Insulators

a Type of Insulator

b Name of Manufacturer of insulators

c Height of the insulatorsd Diameter of the largest shell

e No. of units per stack 2.1 Electrical characteristics (for one insulator)

a Flash over voltage

b Dry power frequency

c Wet power frequencyd Impulse voltage of 1/50 Micro-seconds (+ve)

e Impulse voltage of 1/50 Micro-seconds (-ve)

f Withstand voltagei. Dry voltage

ii. Wet voltage

iii.Impulse voltage of 1/50 Micro-seconds (+ve)iv. Impulse voltage of 1/50 Micro-seconds (-ve)

2.2 Power frequency puncture withstand voltage of unit

2.3 Mechanical characteristicsa Cantilever strength upright

b Cantilever strength under hand

c Torsional strength

d Tensile strength2.4 General characteristics

a Min. creepage distance

b Weight of complete unit2.5 Standard to which insulator conforms

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TECHNICAL SPECIFICATIONS FOR PRESTRESSED CEMENT CONCRETE

POLES

CONDITIONS AND SPECIFICATION (PSCC POLES)

.The manufacture of PSCC Poles consists of the following operations

1. The metal and sand should be sieved and thoroughly washed as per the directionsof the Engineer in the center. The mixing of the concrete will be in proportion of

(1:1:44:2.7) (Nominal).

2. The mixing shall be done in a mixer. The proportion of the mix may be verified atthe discretion of the Engineer.

3. Stretching the 4 mm HT wire between the anchors employing manual labour andwrenches etc to the required tension under the supervision and direction of the

Engineer in-charge of the center and gripping the wires with suitable grippers

without any slip whatsoever. This operation shall be done after setting the moulds

in proper position. Before placing the HT wire inside the form box, the form boxis to be cleaned and thin film of oils is to be applied.

4. Pouring the concrete in the moulds should be done in layers slowly and vibratingshould be done with vibrators.

5. Cutting the wires shall be done with gas cutters or electrical welding set after

allowing the concrete to set in the moulds for prescribed time. The poles shallthen be lifted gently kept in the curing ponds for curing in the site as shown by the

Departmental Engineer at site.

6. Curing the poles shall be for 10 days thoroughly as directed by the Engineer.

7. The cured poles shall be stacked within the premises of the PSCC Center as

directed by the Engineer at site.The cement concrete for casting of the PSCC poles should by M 400 grade using

best river sand and 10 mm to 20 mm HBG metal machine crushed metal should be used

at the ratio of

Sl.No. Description 9.1m/280 Kgs 8.0 m/200 Kgs

1 30% of 20 mm HBG metal 0.071 cum 0.0417 cum



0.237 cum 0.139 cum

Serial number of pole and date of manufacture should be marked clearly a