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IS 1885-54 (1993): Electrotechnical Vocabulary, Part 54:Insulators [ETD 1: Basic Electrotechnical Standards]

May 1993

IS 1886 ( Part 64 ) : 1993 IEC Pub 60 (471) ( 1984 )

oTrTafs Jwr~

Indian Standard

, ~~~E~TR~+TE~H~~G~L~~~Lu~~LARY PART 54 INSULATORS

( First Revision )

UDC 621.315-62 : 001.4

Q BIS 1993

BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG

NEW DELHI 110002

Price Group 3

Basic Electrotechnical Standards Sectional Committee, ET 01

NATIONAL FOREWORD

This Indian Standard ( Part 54 ) ( First Revision ) which is identical with IEC Pub 50 ( 471 ) ( 1984 ) International electrotechnical vocabulary - Chapter 471 : Insulators, issued by the International Electrotechnical Commission ( IEC ), was adopted by the Bureau of Indian Standards on the recommendation of the Basic Electrotechnical Standards Sectional Committee, ET 01 and approval of the Electrotechnical Division Council.

This Indian Standard ( Part 54 ) was first published in 1980. This first revision has been undertaken to align it with the international practice.

Only the English text given in the IEC publication has been retained while adopting as Indian Standard, and as such the page numbers given here are not same as in IEC publication.

IS 1885 ( Part 54) : 1993 IEC Pub 50 (471) (1984)

Indian Standard

ELECTROTECHNICALVOCABULARY PART 54 INSULATORS

(First Revision) SECTION 471-Ol- GENERALTERMS .

471-01-01 insulator A device intended for electrical insulation. and mechanical fixing of equipment or conductors which are subject to potential differences.

471-01-02 fixing device A device, forming part of an insulator, intended to connect it to a supporting structure, or to a conductor, or to an item of equipment, or to another insulator. Note- Where the fixing device is metallic, the term metal fitting is normally used.

471-01-03 core of an insulator The central insulating part of an insulator which provides the mechanical characteristics and from which the sheds project.

471-01-04 shed of an insulator Au insulating part, projecting from the insulator core, intended to increase the creepage distance. The shed can be with or without ribs.

471-01-0s

Id aze A glassy surface layer on the insulating part of a ceramic insulator.

471-01-06 semiconducting glaze A glaze having a resistivity lower than that. of a usual ceramic material or glaze so that its surface resistivity generally lies in the range of lo4 to lo7 Sz. 471-01-07 arcing distance The shortest distance in air external to the insulator between the metallic parts which normally have the operating voltage between them. Note -The term dryarcing distance is also used.

471-01-08 creepage distance The shortest distance along the surface of an insulator between two conductive parts. Note-The surface of cement or of any other non-insulating jointing material is not considered as forming part of the creepage distanti. If high resistance coating is applied to parts

of the insulating part of an insulator such parts are considered to be effective insulating surfaces and the distance over them is included in the creepage distance.

471-01-09 protected creepage distance That part of the creepage distance on the illuminated side of the insulator which would lie in shadow if light were projected on to the insulator at 90 (or 45 in special cases) to the longitudinal axis of the insulator.

471-01-10 spacing The distance between two consecutive points recurring in repetitive positions on an insulator or insulator assembly.

471-M-11 puncture (of an insulator) A disruptive discharge pas,sing through the solid in- sulating material of the insulator which produces a permanent loss of dielectric strength.

471-01-12 flashover (of an insulator) A disruptive discharge external to the irbsulator, and over its surface, connecting those parts which normally have the operating voltage between them.

471-01-13 solid-core insulator An insulator of which the core is solid and composed only ofhomogeneous insulating material.

471-01-14 multi-element insulator An insulator which has an insulating body con$& of two or more disc or bell-shaped insulating elements permanently assembled together and to the fixing device(s). Note -The term multiple cone insulator is included in this definition.

471-01-1s antipollution-type bmWr

An insulatorwhich bas the emma1 pmfie desibed for use in polluted areas.

.471*01-16 stabilized insulator

&u insulator having the wholi surface of the insulating parts covered wifh high resistance coating e.g. semi-

1

Is 1885 ( Part 54) : 1993 IEC Pub 50 (471) (1984)

conducting glaze.

Note - An insulator with high resistance coating or semi- conducting glaze applied to small areas of the insulating parts to reduce local electrical stresses is sometimes called a fringe glazed insulator.

471-01-17

hollow insulator

A hollow insulator which is open from end to end, with or without sheds. Note --Ingeneral, theterm hollow insulatordoes notinclude the fixing devices or end fittings. A hollow insulator may consist of one or two or more peimanently assembled insulat- ing elements.

471-01-18

composite insulator

Insulator made of at least two insulating materials: the core and the external envelope. The composite insulator, for example, can consist either of individual sheds mounted on the core, with or without an intermediate sheath or alternatively, of the complete envelope with sheds directly moulded or cast in one piece on to the core.

471-01-19

camber of an insulator

The maximum distance between the theoretical axis of an insulator and the curved line being the locus of the centres of all the transverse cross-sections of the un- loaded insulator.

471-01-20

deflection under bending load

The displacement of a point on an insulator, measured perpendicularly to its axis, under the effect of a load applied perpendicularly to this axis.

471-01-21

toughened glass

Glass in which pre-stresses have been created in order to improve its mechanical characteristics.

471-01-22

annealed glass

A glass which has been treated to eliminate internal stresses.

SECTION 471-02-TERMS CONCERNING BUSHINGS ,

471-02-01

Adevice that enables one or several conductors to pass

bushing

through a partition such as a wall or a tank, and insu- lates the conductors from it. The means of attachment (flange or fixing device) to the partition forms part of the bushing.

Notes: I-The conductor may form an integral part of the bushing or be drawn into the central tube of the bushing.

2 -The bushings may be of the following types:

liquid filled bushing, liquid insulated bushing;

gas filled bushing;

gas insulated bushing; oil impregnated paper bushing; resin bonded paper bushing; resin impregnated paper bush- ing; ceramic, glass or analogous inorganic material bushing; cast insulation bushing; composite bushing.

471-02-02

capacitance graded bushing

A bushing in which a desired voltage grading is ob- tained by an arrangement of conducting layers incor- porated into the insulating material.

471-02-03

indoor bushing

A bushing both ends of which are intended to be in ambient air at atmospheric pressure but not exposed to outdoor atmospheric.conditions.

471-02-04

A bushing both ends of which are intended to be in

outdoor bushing

ambient air at atmospheric pressure and exposed to outdoor atmospheric conditions.

471-02-05

outdoor-indoor bushing

A bushing both ends of which are intended to be in ambient air at atmospheric pressure. One end is in- tended to be exposed and the other end not to be exposed to outdoor atmospheric conditions.

471-02-06

indoor-immersed bushing

Abushing one end ofwhich is intended to be inambient air but not exposed to outdoor atmospheric conditions and the dther end to be immersed in an insulating medium other than ambient air (e.g. oil or gas).

471-02-07

outdoor-immersed bushing

Abushing one end ofwhich is intended to be in ambient air and exposed to outdoor atmospheric conditions and the other end to be immersed in an insulating medium other than ambient air (e.g. oil or gas).

471-02-08

completely immersed bushing

A bushing both end; of which are intended to be immersed in insulating media other than ambient air (e.g. oil or gas)

471-02-W draw lead bushihg

Abushing not having an integral current-carrying con-

2

IS 1885 (Part 54) : 1993 IEC Pub 50 (471) (1984)

ductor; a cable or other conductor may be drawn it may subsequently be detached to allow the bushing through the bushing and attached to it at one end so that to be withdrawn.

SECTION 471-03 - TERMS CONCERNING INSULATORS FOR OVERHEAD LINES

471-03-01

cap and pin insulator

An insulator comprising an insulating part having the form of a disk or bell, with or without ribs on its lower surface, and fixing devices consisting of an outside cap and an inside pin attached axially.

471-03-02

long rod insulator

An insulator comprising an insulating part having an approximately cylindrical core, with or without sheds, and external or internal fixing devices attached to each end.

471-03-03

string insulator unit

A cap and pin insulator or long rod insulator of which the fixing devices are suitable for flexible attachment to other similar string insulator units or to connecting accessories.

471-03-04

insulator string

Two or more strihg insulator units coupled together and intended to give flexible #support to overhead line conductors and stressed mainly in tension.

471-03-05 inSulator set

An assembly of one or more insulator strings suitably connected together, complete with fixing and protec- tive devices as required in service.

471-03-06

rigid jnsulator

An insulator intended to give rigid support to an over- head line conductor and to be stressed mainly by bend- ing and compressive loads.

471-03-07

pin insulator

A rigid insulator consisting of an insulating component intended to be mounted rigidly on a supporting struc- ture by means of a pin passing up inside the insulating component which consists of one or more pieces of insulating material permanently connected together.

471-03-08

line-post insulator

Arigid insulator consisting of one or more components of insulating material permanently assembled with a metal base and intended to be mounted rigidly on a supporting structure.

471-03-09

shackle insulator

An insulator consisting of one component of insulating material and intended to be secured to the structure by means of a spindle passing through it.

471-03-10 strain insulator

An insulator placed in a structural support such as a guy or span wire to isolate a portion of the support or to prevent leakage current through the support.

471-03-H

ball and socket coupling

A coupling consisting of a ball, a socket and a locking device, and providing flexibility.

471-03-12

clevis and tongue coupling

A coupling consisting of a clevis, a tongue and a clevis-pin and providing limited flexibility.

SECTION 471-04 -TERMS CONCERNING INSULATORS FOR SUBSTATIONS

471-04-01 complete with fixing devices designed to

post insulator attachment to it.

An insulator intended to give rigid support to a live part 471-04.03 which is to be insulated from earth or fromanother live nart.

outdoor post insulator

facilitate

r-- -.

Note - A post insulator may be an assembly of a number of A post insulator intended to be exposed to outdoor

post insulator units. atmospheric conditions.

471-04-02 471-04-04 post insulator unit indoor post insulator

A constituent part of a post insulator consisting of a A post insulator not intended to be exposed to outdoor permanent assembly of one or more insulating parts atmospheric conditions.

3

1s 1885 ( P8ti 54) : 1993 IEC Pub SO (47s) (19lH)

471-w-05

pedestal post insulator

A post insulator having two metal pasts, a cap; partly embracing atrd iusuhrting=uqiponert t&d a $etksbrl cemented into a recess in the insul&zg component; the cap normally has tapped boles and the pedestala flange with plain boles for attachment by bolts or-screws.

A post insulator of approximately cylindrical shape cxmsisting of otle or tnoreinsulating components with a metal fiiting attached to each end; the metal fitting may consist of a cap, insert or flange with plain or tapped boles for attachment by bolts or scnzws.

A

annealed glass 471-01-22 antipollution-type insulator 471-01-1s arcing distance 471-01-07

B

ball and socket coupling 471-03-11 Gushing 471-02-01

C

capacitance graded bushing 471-02-02 camber of an insulator 471-01-19

cap and pin insulator 471-03-01 clevis and tongue coupling 471-03-12 completely immersed bushing 471-02-08 composite insulator 471-01-B core of an insulator 471-01-03 creepage distance 471-01-08

cylindrical post insulator 471-04-06

D

deflection under bending load 471-01-20

draw lead bushing

flashover (of an insulator) fixing device

glaze

hollow insulator

indoor bushing

indoor-immersed bushing indoor post insulator

insulator

INDEX

471-02-09

F

471-01-12 471-01-02

G

471-01-0s

H

471-01-17

I

471-02-03 471-02-06 ._ 471-04-04

471-01-01

insulator set

insulator string

line-post insulator

long rod insulator

multi-element insulator

IS 1885 ( Part 54) : 1993 IEC Pub 50 (471) (1984)

L

471-03-08

471-03-02

M

0

pedestal post insulator pin insulator

post insulator

post insulator unit protected creepage distance puncture (of an insulator)

rigid insulator

semiconducting glaze

shackle insulator shed of an insulator

solid-core insulator

spacing stabilized insulator

strain insulator

string insulator unit

471-01-06

471-03-09

471-01-04

471-01-13

471-01-10 471-01-16

471-03-10

471-03-03

toughened glass 471-01-21

471-03-0s

471-03-04

outdoor bushing 471-02-04 outdoor-immersed bushing 471-02-07 outdoor-indoor bushing 471-02-05 outdoor post insulator 471-04-03

P

471-01-14

471-04-0s 471-03-07

471-04-01

471-04-02 471-01-09

471-01-11

471-03-06

5

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