© BIS 2004

B U R E A U O F I N D I A N S T A N D A R D SMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

IS : 3347 (Part II/Sec 2) - 1979(Reaffirmed 1999)

Edition 2.3(1989-03)

Price Group 5

Indian StandardDIMENSIONS FOR PORCELAIN

TRANSFORMER BUSHINGS FOR USE INLIGHTLY POLLUTED ATMOSPHERES

PART II 3.6 kV BUSHINGS

Section 2 Metal Parts

( First Revision )(Incorporating Amendment Nos. 1, 2 & 3)

UDC 621.315.626-2 : 621.315.612.2 : 006.78.621.314.21

IS : 3347 (Part II/Sec 2) - 1979

© BIS 2004

BUREAU OF INDIAN STANDARDS

This publication is protected under the Indian Copyright Act (XIV of 1957) andreproduction in whole or in part by any means except with written permission of thepublisher shall be deemed to be an infringement of copyright under the said Act.

Indian StandardDIMENSIONS FOR PORCELAIN

TRANSFORMER BUSHINGS FOR USE INLIGHTLY POLLUTED ATMOSPHERES

PART II 3.6 kV BUSHINGS

Section 2 Metal Parts

( First Revision )Electrical Insulators and Accessories Sectional Committee, ETDC 3

Chairman Representing

SHRI L. C. JAIN Ministry of Energy, New Delhi

Members

SHRI V. R. ANANTHANARAYANAN Bengal Potteries Ltd, CalcuttaSHRI CHANDER PARKASH ( Alternate )

SHRI B. C. BANERJEE All India Pottery Manufacturers’ Association,Calcutta

SHRI B. C. DAW ( Alternate )SHRI D. S. CHABHAL Directorate General of Technical Development,

New DelhiSHRI R. T. CHARI Tag Corporation, Madras

SHRI A. GURUPATHAM ( Alternate )SHRI K. S. CHELLAPPAN Tamil Nadu Electricity Board, Madras

SHRI N. R. SANKARAN ( Alternate )SHRI A. K. CHOPRA Punjab State Electricity Board, Patiala

SHRI NIRVAIR SINGH ( Alternate )SHRI A. N. DEB Damodar Valley Corporation, Calcutta

SHRI A. C. BOSE ( Alternate )DIRECTOR OF RESEARCH (T & D) Maharashtra State Electricity Board, BombayDIRECTOR (TRACTION AND

INSTALLATION)Research, Designs & Standards Organization,

Ministry of Railways, LucknowJOINT DIRECTOR STANDARDS (T1)

( Alternate )DIRECTOR (TRANSMISSION) Central Electricity Authority, New Delhi

DEPUTY DIRECTOR (SUBSTATION)( Alternate )

( Continued on page 2 )

IS : 3347 (Part II/Sec 2) - 1979

2

( Continued from page 1 )

Members RepresentingGENERAL MANAGER (T)

DIRECTOR OF TELEGRAPHS (L)( Alternate )

DIVISIONAL ENGINEER TELE-GRAPHS (C) ( Alternate )

Director General of Posts & Telegraphs, Jabalpur

SHRI B. N. GHOSH Bharat Heavy Electricals Ltd, BhopalSHRI H. M. S. LINGAIAH Karnataka Electricity Board, BangaloreSHRI G. S. MAHAGAONKAR Mysore Porcelains Ltd, BangaloreSHRI S. K. MUKHERJEE

SHRI U. S. VERMA ( Alternate )National Test House, Calcutta

DR G. M. PHADKESHRI C. R. VARRIER ( Alternate )

Indian Electrical Manufacturers’ Association,Bombay

SHRI P. S. RAMANSHRI E. P. WILFRED ( Alternate )

NGEF Limited, Bangalore

SHRI M. SANKARALINGAMDY DIRECTOR OF INSPECTION

( Alternate )

Directorate General of Supplies & Disposals, NewDelhi

SHRI P. K. SAXENASHRI G. L. DUA ( Alternate )

Rural Electrification Corporation Limited, NewDelhi

SHRI N. S. SEETHURAMONSHRI V. SRINIVASAN ( Alternate )

W. S. Insulators of India Ltd, Madras

DR U. S. SINGHSHRI A. D. DUA ( Alternate )

High Tension Insulator Factory, Ranchi

SHRI SURENDRA SINGH U. P. Government Pottery Development Centre,Khurja

SHRI T. B. L. SRIVASTAVA ( Alternate )SHRI L. VENKATESUBBU

SHRI R. V. ACHUTHAN ( Alternate )Seshasayee Industries Ltd, Vadalur South Arcot,

DistrictSHRI S. P. SACHDEV,

Director (Elec tech)Director General, ISI ( Ex-officio Member )

SecretarySHRI R. S. SARMA

Assistant Director (Elec tech), ISI

Panel for Dimensions of Bushings, ETDC 3 : P3

ConvenerSHRI V. SRINIVASAN W. S. Insulators of India Ltd, Madras

MembersSHRI K. N. JAYARAM Mysore Porcelains Ltd, BangaloreSHRI S. V. MANERIKAR Crompton Greaves Ltd, BombaySHRI M. L. MITTAL Bharat Heavy Electricals Ltd, Bhopal

SHRI S. P. SINGH ( Alternate )SHRI R. G. PRADHANANI Bharat Bijlee Ltd, BombaySHRI P. RAMACHANDRAN Transformers & Electricals Kerala Ltd,

Angamally South P. O.SHRI KURIAKOSE ANTONY ( Alternate )

SHRI P. S. RAMAN NGEF Limited, BangaloreDR U. S. SINGH High Tension Insulator Factory, Ranchi

SHRI A. D. DUA ( Alternate )

IS : 3347 (Part II/Sec 2) - 1979

3

Indian StandardDIMENSIONS FOR PORCELAIN

TRANSFORMER BUSHINGS FOR USE INLIGHTLY POLLUTED ATMOSPHERES

PART II 3.6 kV BUSHINGS

Section 2 Metal Parts

( First Revision )0. F O R E W O R D

0.1 This Indian Standard (Part II/Sec 2) (First Revision) was adoptedby the Indian Standards Institution on 29 August 1979, after the draftfinalized by the Electrical Insulators and Accessories SectionalCommittee had been approved by the Electrotechnical DivisionCouncil.0.2 This standard was first issued in 1967. This revision has beenundertaken with a view to including details of fixing arrangements ofjumpers at oil end. This revision also incorporates amendment issuedto the original standard.0.3 The dimensions of porcelain parts of the bushings for use in lightlypolluted atmospheres of 3.6 kV are covered in IS : 3347 (Part II/Sec1)-1979*. This section (Section 2), which is a necessary adjunct toSection 1, lays down the dimensions of the metal parts and accessoriesof the bushings to go with the porcelain parts specified in Section 1.The materials of the metal parts have also been specified.0.4 The need for changing over to aluminium for the metal parts ofbushings has been fully recognized. This section, therefore, includescomplete sets of dimensions of parts using aluminium as well ascopper. Dimensions for copper parts have been given to ensure asmooth changeover to aluminium. These are expected to be deleted indue course.0.5 In this section, the dimensions of metal parts have beenformulated in such a way that the porcelain parts available inSection 1 of this standard may be used both for aluminium as well ascopper metal parts. Suitable references are given to indicate theappropriate porcelain part at each place.0.6 For a current rating of 3 150A, no aluminium metal parts havebeen specified. In this case the use of copper metal parts only isrecommended.

*Dimensions for porcelain transformer bushings for use in normal and lightlypolluted atmospheres : Part II 3.6 kV bushings, Section 1 Porcelain parts ( first revision ).

IS : 3347 (Part II/Sec 2) - 1979

4

0.7 The dimensions of bushings for other voltages are covered by thefollowing parts of this standard:

Part I Up to and including 1 kVSection 1 Porcelain partsSection 2 Metal parts

Part III 12 and 17.5 kV BushingsSection 1 Porcelain partsSection 2 Metal parts

Part IV 24 kV BushingsSection 1 Porcelain partsSection 2 Metal parts

Part V 36 kV BushingsSection 1 Porcelain partsSection 2 Metal parts

Part VI 72.5 kV BushingsSection 1 Porcelain partsSection 2 Metal parts ( under preparation )

Part VII 123 kV BushingsSection 1 Porcelain partsSection 2 Metal parts ( under preparation )

0.8 The dimensions for porcelain transformer bushings for use inheavily polluted atmospheres are covered by IS : 8603 ( Parts I to III)-1977*. The metal parts covered by this section may be used for bushingscovered by IS : 8603 (Parts I to III)-1977*.0.9 In the preparation of this standard, assistance has been derivedfrom DIN 42539 (1968) ‘Indoor and outdoor transformers, bushingsvoltage rating 3 kV for 250 to 3 150A’, issued by DeutscherNormenausschuss.0.10 This edition 2.3 incorporates Amendment No. 1 (June 1982),Amendment No. 2 (April 1987) and Amendment No. 3 (March 1989).Side bar indicates modification of the text as the result of incorporationof the amendments.0.11 For the purpose of deciding whether a particular requirement ofthis standard is complied with, the final value, observed or calculated,expressing the result of a test, shall be rounded off in accordance withIS : 2-1960†. The number of significant places retained in the roundedoff value should be the same as that of the specified value in thisstandard.

*Dimensions for porcelain transformer bushings for use in heavily pollutedatmospheres:

Part I 12 and 17.5 kV bushings,Part II 24 kV bushings, andPart III 36 kV bushings.

†Rules for rounding off numerical values ( revised ).

IS : 3347 (Part II/Sec 2) - 1979

5

1. SCOPE

1.1 This standard (Part II/Sec 2) lays down the dimensions andmaterials of metal parts and accessories of 3.6 kV rating bushingsused with transformers for use in lightly polluted atmospheres.

2. MATERIALS

2.1 The materials of various parts shall conform to the relevant IndianStandards specified below:

*Specification for precision and semi-precision hexagon bolts, screws, nuts and locknuts (diameter range 6 to 39 mm) ( first revision ).

†Specification for copper rods for electrical purposes ( revised ).‡Specification for aluminium ingots (EC grade) ( first revision ).§Specification for brass bars, rods and sections suitable for forging.||Specification for brass ingots and castings ( revised ).¶Specification for free-cutting brass bars, rods and sections ( third revision ).

Metal Part orAccessory

For Bushing withCopper Stem

For Bushing with Aluminium Stem

Hexagonal nut (4.1) Brass conforming to 2.2of IS : 1364-1967*

Aluminium alloy confor-ming to 2.2 of IS : 1364-1967*

Stem (3.2) Copper rods conformingto IS : 613-1964†

Aluminium conforming toelectrical grade ofIS : 4026- 1969‡ or anyother suitable alumi-nium alloy to be agreedbetween manufacturerand the purchaser

Nut (3.3) Brass conforming toIS : 3488-1966§ orGrade 2 of IS : 292-1961|| or IS : 319-1974¶

Aluminium conforming toelectrical grade of IS :4026-1969‡ or any othersuitable aluminium alloyto be agreed betweenmanufacturer and thepurchaser

Washer (top end) (3.5) Brass conforming toType I of IS : 319-1974¶ or IS : 3488-1966§

—do—

Washer (stem) (3.6) Brass conforming toType I of IS : 319-1974¶ or IS : 3488-1966§

—do—

IS : 3347 (Part II/Sec 2) - 1979

6

NOTE — For 250 A rated bushing, brass conforming to IS : 3488-1966† may be usedfor manufacture of stem in place of copper rod.

2.2 The material used for sealing washers for general purposes (fourtypes M, N, P and Q) shall be synthetic rubber or synthetic rubberbonded cork. The material used for sealing washers for stem shall besynthetic rubber (acrylic nitrile rubber) having hardness of 70 ±5 IRHD. Where synthetic insulating transformer coolant is used, thematerial of the washer shall be silicone rubber or any other resilientmaterial compatible with the transformer coolant.

3. DIMENSIONS

3.1 The hexagonal nuts used shall conform to IS : 1364-1967§ andIS : 3138-1966||. The threads shall be in accordance withIS : 1362-1962¶ and IS : 3139-1966**.

3.2 Stem

3.2.1 For 3.6/250 and 630 Rating ( Copper Stem ) and for 3.6/250Rating ( Aluminium Stem ) — The dimensions shall conform to Fig. 1.

3.2.2 For 3.6/1 000, 2 000 and 3 150 Rating ( Copper Stem ) and for3.6/630, 1 000 and 2 000 Rating ( Aluminium Stem ) — Thedimensions shall conform to Fig. 2.

Metal Part orAccessory

For Bushing withCopper Stem

For Bushing with Aluminium Stem

Connecting lug For 1 000 and 2 000 Abrass conforming toGrade 3 of IS :292-1961* or to IS :3488-1966†

For 3 150 A copperchromium alloy

Aluminium alloyconforming to A-6-Mdesignation of IS : 617-1975‡ or any othersuitable aluminium alloyto be agreed between themanufacturer and thepurchaser

*Specification for brass ingots and castings ( revised ).†Specification for brass bars, rods and sections suitable for forging.‡Specification for aluminium and aluminium alloy ingots and castings for general

engineering purposes ( second revision ).§Specification for precision and semi-precision hexagon bolts, screws, nuts and lock

nuts diameter range 6 to 39 mm ( first revision ).||Specification for hexagonal bolts and nuts (M 42 to M 150).¶Dimensions for screw threads for general purposes (diameter range 1.6 to 39 mm)

( revised ).**Dimensions for screw threads for bolts and nuts (diameter range M 42 to M 150).

IS : 3347 (Part II/Sec 2) - 1979

7

3.3 Nut

3.3.1 For 3.6/250 and 630 Rating ( Copper Stem ) and for 3.6/250Rating ( Aluminium Stem ) — The dimensions shall conform to Fig. 3.

3.3.2 For 3.6/1 000 Rating ( Copper Stem ) and 3.6/630 Rating( Aluminium Stem ) — The dimensions shall conform to Fig. 4.

3.3.3 For 3.6/2 000 and 3 150 Rating ( Copper Stem ) and for 3.6/1 000,2 000 Rating ( Aluminium Stem ) — The dimensions shall conform toFig. 5.

3.4 Stem Subassembly

3.4.1 For 3.6/250 and 630 Rating ( Copper Stem ) and for 3.6/250 and630 Rating ( Copper Stem ) and for 3.6/250 Rating ( Aluminium Stem )— The subassembly shall conform to Fig. 6.

3.4.2 For 3.6/1 000, 2 000 and 3 150 Rating ( Copper Stem ) and3.6/630, 1 000 and 2 000 Rating ( Aluminium Stem ) — Thesubassembly shall conform to Fig. 7.

3.5 Washer (Top End) — The washer (top end) shall conform toFig. 8.

3.6 Washer (Stem) — The washer (stem) shall conform to Fig. 9.

3.7 Sealing Washers

3.7.1 For Stem — The sealing washer for stem shall conform to Fig. 10.

3.7.2 General Purpose ( four Types M, N, O and P ) — The generalpurposes sealing washer shall be in accordance with Fig. 11.

3.7.3 Gasket ( R and X Type ) — The gasket shall conform to Fig. 12.

3.8 Connecting Lug — The connecting lug shall conform to Fig. 13.

4. TOLERANCES

4.1 Unless otherwise specified allowable tolerance on a dimension ofany machined metal part shall be in accordance with medium class ofIS : 2102-1969*.

4.2 Unless otherwise specified, allowable tolerance on a dimension ofany forged or cast metal part shall be in accordance with coarse classof IS : 2102-1969*.

5. ASSEMBLY

5.1 The assembly of the bushing is shown in Fig. 14.

*Specification for allowable deviations for dimensions without specified tolerances( first revision ).

IS : 3347 (Part II/Sec 2) - 1979

8

NOTE — The chamfered ends shall be in accordance with IS : 1368-1967* and f andx shall be in accordance with IS : 1369-1975†.

TYPE OF STEM

BUSHING RATING kV/A

CORRESPONDING RATING OF PORCELAIN

PART OF SEC 1, kV/A

d1 l1 l2 l3

(1) (2) (3) (4) (5) (6) (7)Copper and

aluminium3.6/250 3.6/250 M12 272 71 38.5

Copper 3.6/630 3.6/630 M20 318 100 53*Dimensions of ends of bolts and screws ( first revision ).†Dimensions of screw threads run out and undercuts ( first revision ).

FIG. 1 STEM FOR 250 AND 630A RATING

TYPE OF STEM

BUSHING RATING kV/A

CORRESPONDING RATING OF PORCELAIN

PART OF SEC 1, kV/A

d1 d13 c8 l1 l2 l3

(1) (2) (3) (4) (5) (6) (7) (8)

AluminiumCopperAluminiumCopperAluminiumCopper

3.6/6303.6/1 0003.6/1 0003.6/2 0003.6/2 0003.6/3 150

3.6/1 0003.6/1 0003.6/2 0003.6/2 0003.6/3 1503.6/3 150

M30 × 2M30 × 2M42 × 3M42 × 3M48 × 3M48 × 3

292941414747

300300340340353353

110110140140148148

242429293434

NOTE — f and x shall be in accordance with IS : 1369-1975*.*Dimensions of screw threads run out and undercuts ( first revision ).

FIG. 2 STEM FOR 1 000, 2 000 AND 3 150A RATING

IS : 3347 (Part II/Sec 2) - 1979

9

TYPE OF STEM

BUSHING RATING kV/A

CORRESPONDING RATING OF PORCELAIN

PART OF SEC 1, kV/A

d14 d15 d16Max

h7 l3Max

(1) (2) (3) (4) (5) (6) (7) (8)

AluminiumCopper

Copper

3.6/250

3.6/630

3.6/250

3.6/630

M12

M20

45

63

24

39

15

18

19

27

FIG. 3 NUT FOR 250 AND 630A RATING

FIG. 4 NUT FOR 630 AND 1 000A RATING

IS : 3347 (Part II/Sec 2) - 1979

10

TYPE OF STEM

BUSHING RATING

kV/A

CORRES-PONDING

RATING OF PORCELAIN

PART OF SEC 1, kV/A

d17H8

d18Max

d19Max

h8 h9±0.3

d4Max

l6

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

Aluminium

Copper

Aluminium

Copper

3.6/1 000

3.6/2 000

3.6/2 000

3.6/3 150

3.6/2 000

3.6/2 000

3.6/3 150

3.6/3 150

41

41

47

47

62

62

78

78

56

56

66

66

34

34

39

39

27

27

32

32

50

50

60

60

100

100

110

110

FIG. 5 NUT FOR 2 000 AND 3 150A RATING

IS : 3347 (Part II/Sec 2) - 1979

11

TYPE OFSTEM

BUSHING RATINGkV/A

CORRESPONDING RATING OF PORCELAIN

PART OF SEC 1,kV/A

l4±0.3 STEM NUT

(1) (2) (3) (4) (5) (6)

Copper and Aluminium

Copper

3.6/250

3.6/630

3.6/250

3.6/630

25

37

See Fig. 1

See Fig. 1

See Fig. 3

See Fig. 3

FIG. 6 STEM SUBASSEMBLY FOR 250 AND 630A RATING

IS : 3347 (Part II/Sec 2) - 1979

12

TYPE OFSTEM

BUSHING RATING

kV/A

CORRESPONDING RATING OF PORCELAIN

PART OF SEC 1,kV/A

l5 STEM NUT

(1) (2) (3) (4) (5) (6)

Aluminium

Copper

Aluminium

Copper

Aluminium

Copper

3.6/630

3.6/1 000

3.6/1 000

3.6/2 000

3.6/2 000

3.6/3 150

3.6/1 000

3.6/1 000

3.6/2 000

3.6/2 000

3.6/3 150

3.6/3 150

307

307

347

347

360

360

See Fig. 2

See Fig. 2

See Fig. 2

See Fig. 2

See Fig. 2

See Fig. 2

See Fig. 4

See Fig. 4

See Fig. 5

See Fig. 5

See Fig. 5

See Fig. 5

FIG. 7 STEM SUBASSEMBLY FOR 630, 1 000, 2 000 AND 3 150A RATING

IS : 3347 (Part II/Sec 2) - 1979

13

BUSHING RATINGkV/A

BUSHING WITH ALUMINIUM STEM BUSHING WITH COPPER STEM

d2 d20 d21 h10 t d2 d20 d21 h10 t

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)

3.6/2503.6/6303.6/1 0003.6/2 0003.6/3 150

28567080—

13314350—

22455965—

20242626—

1.5333—

2840567080

1321314350

2232455965

2022242626

1.52333

FIG. 8 WASHER (TOP END)

BUSHING RATINGkV/A

BUSHING WITH ALUMINIUM STEM BUSHING WITH COPPER STEM

d22 d23 d24 d25 h11 d22 d23 d24 d25 h11

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)

3.6/2503.6/6303.6/10003.6/20003.6/3150

28567080—

13314350—

22455965—

326580

100—

4678

—

2840567080

1321314350

2232455965

32476580

100

45678

FIG. 9 WASHER (STEM)

IS : 3347 (Part II/Sec 2) - 1979

14

BUSHING RATINGkV/A

BUSHING WITH ALUMINIUMSTEM

BUSHING WITH COPPERSTEM

d28±0.3 d29 S1 d28±0.3 d29 S1

(1) (2) (3) (4) (5) (6) (7)

3.6/2503.6/6303.6/1 0003.6/2 0003.6/3 150

22455965—

12304248—

11161818—

2232455965

1220304248

1113161818

FIG. 10 SEALING WASHER FOR STEM

TYPE BUSHING RATINGkV/A

BUSHING WITH ALUMINIUMSTEM

BUSHING WITH COPPERSTEM

d30 d31 S2 d30 d31 S2

(1) (2) (3) (4) (5) (6) (7) (8)

MMMMMNNNNNPPOO

3.6/2503.6/6303.6/1 0003.6/2 0003.6/3 1503.6/2503.6/6303.6/1 0003.6/2 0003.6/3 1503.6/2503.6/6303.6/2503.6/630

326580

100—6090

104125

—45—60—

14324550—38567090—25—38—

2222—4444—2—2—

32476580906070

100104125

45636070

1422324550384556709025403845

22222444442222

FIG. 11 GENERAL PURPOSE WASHER (FOUR TYPES M, N, O AND P)

IS : 3347 (Part II/Sec 2) - 1979

15

TYPE RATINGkV/A

BUSHING WITH ALUMINIUMSTEM

BUSHING WITH COPPERSTEM

d26 d27 T d26 d27 T

(1) (2) (3) (4) (5) (6) (7) (8)

R

R

R

R

R

X

X

X

X

X

3.6/250

3.6/630

3.6/1 000

3.6/2 000

3.6/3 150

3.6/250

3.6/630

3.6/1 000

3.6/2 000

3.6/3 150

45

56

70

90

—

40

45

63

80

—

70

90

104

125

—

70

70

90

110

—

3

3

3

3

—

3

3

3

3

—

28

40

45

70

90

25

45

56

70

90

50

70

70

104

125

50

70

90

104

125

3

3

3

3

3

3

3

3

3

3

FIG. 12 GASKET ( R AND X TYPE )

As in the Original Standard, this Page is Intentionally Left Blank

IS : 3347 (Part II/Sec 2) – 1979

17

BUSHING RATING

kV/A

WITH ALUMINIUM STEM

C D1 D2 D20 G H11 H12 H13 S W N T P Q R4 R5 U V

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19)

3.6/1 000 58 M42 × 3 18 M16 40 195 80 100 50 25 45 35 20 18 15 20 15 26

3.6/2 000 68 M48 × 3 18 M16 40 220 80 120 60 30 45 35 20 18 15 20 15 30

WITH COPPER STEM

3.6/1 000 45 M30 × 2 14 M12 30 130 60 060 32 14 30 25 12 10 10 15 10 16

3.6/2 000 58 M42 × 3 18 M16 40 195 80 100 50 25 45 35 20 18 15 20 15 26

3.6/3 150 68 M48 × 3 18 M16 40 220 80 120 60 30 45 35 20 18 15 20 15 30

FIG. 13 CONNECTING LUG

IS : 3347 (Part II/Sec 2) – 1979

18

1. Insulator (top)2. Insulator (bottom)3. Stem4. Washer (top end)5. Washer (stem)6. Connecting lug7. Sealing Washer (stem)

8. Sealing washer M Type9. General purpose washer10. Gasket X11. Gasket R12. Washer in accordance with IS : 2016-1967†13. Nut14. Spring washer (Type B as per IS : 3063-1972‡)

TYPE OF STEM BUSHING RATINGkV/A

aMax

bMax

d1 d2 d3 d4 d5

Aluminium

3.6/2503.6/6303.6/1 0003.6/2 0003.6/3 150

180290372402—

94808692—

M12 × 0M30 × 2M42 × 3M48 × 3

—

28567080—

39567090—

070110125150—

075110125145—

Copper

3.6/2503.6/6303.6/1 0003.6/2 0003.6/3 150

180210294372404

94110808692

M12 × 0M20 × 0M30 × 2M42 × 3M48 × 3

2846567090

3945567090

070085110125150

07590

110125145

*4 to 8 up to and including 1 000 A, 6 to 10 above 1 000 A.†Specification for plain washers ( first revision ).‡Specification for single coil rectangular section spring washers for bolts, nuts and screws ( first revision ).

FIG. 14 ASSEMBLY OF BUSHING

Bureau of Indian StandardsBIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promoteharmonious development of the activities of standardization, marking and quality certification ofgoods and attending to connected matters in the country.

CopyrightBIS has the copyright of all its publications. No part of these publications may be reproduced in anyform without the prior permission in writing of BIS. This does not preclude the free use, in the courseof implementing the standard, of necessary details, such as symbols and sizes, type or gradedesignations. Enquiries relating to copyright be addressed to the Director (Publications), BIS.

Review of Indian StandardsAmendments are issued to standards as the need arises on the basis of comments. Standards are alsoreviewed periodically; a standard along with amendments is reaffirmed when such review indicatesthat no changes are needed; if the review indicates that changes are needed, it is taken up forrevision. Users of Indian Standards should ascertain that they are in possession of the latestamendments or edition by referring to the latest issue of ‘BIS Catalogue’ and ‘Standards : MonthlyAdditions’.This Indian Standard has been developed by Technical Committee : ETDC 3

Amendments Issued Since Publication

Amend No. Date of IssueAmd. No. 1 June 1982Amd. No. 2 April 1987Amd. No. 3 March 1989

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Telegrams: Manaksanstha(Common to all offices)

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Northern : SCO 335-336, Sector 34-A, CHANDIGARH 160022 60 38 4360 20 25

Southern : C. I. T. Campus, IV Cross Road, CHENNAI 600113 235 02 16, 235 04 42235 15 19, 235 23 15

Western : Manakalaya, E9 MIDC, Marol, Andheri (East)MUMBAI 400093

832 92 95, 832 78 58832 78 91, 832 78 92

Branches : AHMEDABAD. BANGALORE. BHOPAL. BHUBANESHWAR. COIMBATORE.FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. LUCKNOW.NAGPUR. NALAGARH. PATNA. PUNE. RAJKOT. THIRUVANANTHAPURAM.VISHAKHAPATNAM