EN 61952:2003

Insulators for overhead lines - Composite line post insulators for alternative current with a nominal voltage > 1 000 V

Applies to composite line post insulators consisting of a load-bearing, cylindrical, insulating solid core made up of fibres - usually glass - in a resin-based matrix, a housing (outside the insulating core) made of elastomer material (e.g. silicone or ethylene-propylene) and end fittings permanently attached to the insulating core. The object of this standard is to - define the terms used, - prescribe test methods, - prescribe acceptance or failure criteria This standard does not include requirements dealing with the choice of insulators for specific operating conditions.

Isolatoren für Freileitungen - Verbund-Freileitungsstützer für Wechselspannungsfreileitungen mit einer Nennspannung über 1 000 V

Isolateurs pour lignes aériennes - Isolateurs composites rigides à socle pour courant alternatif de tension nominale > 1 000 V

Est applicable aux isolateurs composites rigides à socle constitués d'un noyau isolant cylindrique supportant la charge, composé de fibres - habituel-lement en verre - dans une matrice à base de résine, d'un revêtement (extérieur au noyau isolant) en matériau élastomère (par exemple silicone ou éthylène-propylène) et d'armatures d'extrémité reliées de façon permanente au noyau isolant. La présente norme a pour objet: - de définir les termes employés, - de fixer les méthodes d'essai, - de fixer les critères d'acceptation ou de rejet d'une fourniture. Cette norme n'inclut pas d'exigences relatives au choix des isolateurs pour des conditions de service spécifiques.

Insulators for overhead lines - Composite line post insulators for alternative current with a nominal voltage > 1000 V (IEC 61952:2002)

General Information

• Status: Withdrawn
• Publication Date: 28-Feb-2003
• Withdrawal Date: 30-Nov-2005
• ICS: 29.080.10 - Insulators
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: CLC/SR 36B - Insulators for overhead lines
• Drafting Committee: IEC/SC 36B - IEC_SC_36B
• Parallel Committee: IEC/SC 36B - IEC_SC_36B
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 01-Sep-2011
• Completion Date: 01-Sep-2011
• Ref Project: SIST EN 61952:2004 - Insulators for overhead lines - Composite line post insulators for alternative current with a nominal voltage > 1 000 V

Relations

• Replaced By: EN 61952:2008 - Insulators for overhead lines - Composite line post insulators for A.C. systems with a nominal voltage greater than 1 000 V - Definitions, test methods and acceptance criteria
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61952:2004
01-september-2004
Insulators for overhead lines - Composite line post insulators for alternative
current with a nominal voltage > 1000 V (IEC 61952:2002)

Insulators for overhead lines - Composite line post insulators for alternative current with a

nominal voltage > 1 000 V
Isolatoren für Freileitungen - Verbund-Freileitungsstützer für
Wechselspannungsfreileitungen mit einer Nennspannung über 1 000 V

Isolateurs pour lignes aériennes - Isolateurs composites rigides à socle pour courant

alternatif de tension nominale > 1 000 V
Ta slovenski standard je istoveten z: EN 61952:2003
ICS:
29.080.10 Izolatorji Insulators
29.240.20 Daljnovodi Power transmission and
distribution lines
SIST EN 61952:2004 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 61952:2004
---------------------- Page: 2 ----------------------
SIST EN 61952:2004
EUROPEAN STANDARD EN 61952
NORME EUROPÉENNE
EUROPÄISCHE NORM January 2003
ICS 29.080.10; 29.240.20
English version
Insulators for overhead lines -
Composite line post insulators for alternative current
with a nominal voltage > 1 000 V
(IEC 61952:2002)
Isolateurs pour lignes aériennes - Isolatoren für Freileitungen -
Isolateurs composites rigides à socle Verbund-Freileitungsstützer
pour courant alternatif für Wechselspannungsfreileitungen
de tension nominale > 1 000 V mit einer Nennspannung über 1 000 V
(CEI 61952:2002) (IEC 61952:2002)

This European Standard was approved by CENELEC on 2002-12-01. CENELEC members are bound to

comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,

Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,

Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61952:2003 E
---------------------- Page: 3 ----------------------
SIST EN 61952:2004
EN 61952:2003 - 2 -
Foreword

The text of document 36B/208/FDIS, future edition 1 of IEC 61952, prepared by SC 36B, Insulators for

overhead lines, of IEC TC 36, Insulators, was submitted to the IEC-CENELEC parallel vote and was

approved by CENELEC as EN 61952 on 2002-12-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-12-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annex ZA is normative and annexes A, B and C are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 61952:2002 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:

IEC 60507 NOTE Harmonized as EN 60507:1993 (not modified).
__________
---------------------- Page: 4 ----------------------
SIST EN 61952:2004
- 3 - EN 61952:2003
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

This European Standard incorporates by dated or undated reference, provisions from other

publications. These normative references are cited at the appropriate places in the text and the

publications are listed hereafter. For dated references, subsequent amendments to or revisions of any

of these publications apply to this European Standard only when incorporated in it by amendment or

revision. For undated references the latest edition of the publication referred to applies (including

amendments).

NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
Publication Year Title EN/HD Year
IEC 60060-1 1989 High-voltage test techniques
+ corr. March 1990 Part 1: General definitions and test HD 588.1 S1 1991
requirements
IEC 60383-1 1993 Insulators for overhead lines with a EN 60383-1 1996
nominal voltage above 1 kV A11 1999
Part 1: Ceramic or glass insulator units
for a.c. systems - Definitions, test
methods and acceptance criteria
IEC 60383-2 1993 Part 2: Insulator strings and insulator EN 60383-2 1995
sets for a.c. systems - Definitions, test
methods and acceptance criteria
IEC 60695-11-10 1999 Fire hazard testing EN 60695-11-10 1999
Part 11-10: Test flames - 50 W
horizontal and vertical flame test
methods
ISO 868 1985 Plastics and ebonite - Determination of EN ISO 868 1997
indentation hardness by means of a
durometer (Shore hardness)
ISO 3274 1996 Geometrical Product Specifications EN ISO 3274 1997
Cor 1 1998 (GPS) - Surface texture: Profile
method - Nominal characteristics of
contact (stylus) instruments
ISO 3452 Series Non-destructive testing - Penetrant - -
inspection
ISO 4287 1997 Geometrical Product Specifications EN ISO 4287 1998
Cor 1 1998 (GPS) - Surface texture: Profile
method - Terms, definitions and
surface texture parameters
ISO 4892-1 1999 Plastics - Methods of exposure to EN ISO 4892-1 2000
laboratory light sources
Part 1: General guidance
---------------------- Page: 5 ----------------------
SIST EN 61952:2004
EN 61952:2003 - 4 -
Publication Year Title EN/HD Year
ISO 4892-2 1994 Part 2: Xenon arc sources EN ISO 4892-2 1999
ISO 4892-3 1994 Part 3: Fluorescent UV lamps EN ISO 4892-3 1999
---------------------- Page: 6 ----------------------
SIST EN 61952:2004
NORME CEI
INTERNATIONALE IEC
61952
INTERNATIONAL
Première édition
STANDARD
First edition
2002-07
Isolateurs pour lignes aériennes –
Isolateurs composites rigides
à socle pour courant alternatif
de tension nominale >1 000 V
Insulators for overhead lines –
Composite line post insulators
for alternative current
with a nominal voltage >1 000 V
 IEC 2002 Droits de reproduction réservés  Copyright - all rights reserved

Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any

utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including

électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from

microfilms, sans l'accord écrit de l'éditeur. the publisher.

International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch

CODE PRIX
Commission Electrotechnique Internationale PRICE CODE
International Electrotechnical Commission
Международная Электротехническая Комиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
---------------------- Page: 7 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 3 –
CONTENTS

FOREWORD .......................................................................................................................... 5

INTRODUCTION ....................................................................................................................7

1 Scope and object ............................................................................................................11

2 Normative references......................................................................................................11

3 Definitions ......................................................................................................................13

4 Identification ...................................................................................................................17

5 Classification of tests......................................................................................................17

5.1 Design tests ..........................................................................................................17

5.2 Type tests..............................................................................................................21

5.3 Sample tests..........................................................................................................21

5.4 Routine tests .........................................................................................................21

6 Design tests....................................................................................................................21

6.1 General .................................................................................................................21

6.2 Tests on interfaces and connections of end fittings................................................21

6.3 Assembled core load tests.....................................................................................25

6.4 Tests of shed and housing material .......................................................................27

6.5 Tests for the core material .....................................................................................33

7 Type tests.......................................................................................................................35

7.1 Verification of dimensions......................................................................................37

7.2 Electrical tests .......................................................................................................37

7.3 Mechanical tests....................................................................................................39

8 Sample tests...................................................................................................................41

8.1 General rules.........................................................................................................41

8.2 Verification of dimensions (E1 + E2) ......................................................................41

8.3 Galvanizing test (E1 + E2) .....................................................................................41

8.4 Verification of the SCL (E1) ...................................................................................41

8.5 Re-testing procedure .............................................................................................43

9 Routine tests ..................................................................................................................43

9.1 Tensile load test ....................................................................................................43

9.2 Visual examination ................................................................................................43

Annex A (informative) Notes on the mechanical loads and tests...........................................51

Annex B (informative) Determination of the equivalent bending moment

caused by combined loads..............................................................................................55

Annex C (informative) Explanation of the concept of classes for the design tests .................61

Bibliography..........................................................................................................................63

Figure 1 – Thermal-mechanical pre-stressing test –Typical cycles ........................................45

Figure 2 – Example of a boiling container for the water diffusion test ....................................47

Figure 3 – Electrodes for the voltage test ..............................................................................49

Figure 4 – Typical circuit for the voltage test .........................................................................49

Figure B.1 – Combined loads applied to unbraced insulators.................................................57

Figure B.2 – Combined loads applied to braced insulators ....................................................59

---------------------- Page: 8 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATORS FOR OVERHEAD LINES –
COMPOSITE LINE POST INSULATORS FOR ALTERNATIVE CURRENT
WITH A NOMINAL VOLTAGE >>1 000 V
FOREWORD

1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, the IEC publishes International Standards. Their preparation is

entrusted to technical committees; any IEC National Committee interested in the subject dealt with may

participate in this preparatory work. International, governmental and non-governmental organizations liaising

with the IEC also participate in this preparation. The IEC collaborates closely with the International

Organization for Standardization (ISO) in accordance with conditions determined by agreement between the

two organizations.

2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an

international consensus of opinion on the relevant subjects since each technical committee has representation

from all interested National Committees.

3) The documents produced have the form of recommendations for international use and are published in the form

of standards, technical specifications, technical reports or guides and they are accepted by the National

Committees in that sense.

4) In order to promote international unification, IEC National Committees undertake to apply IEC International

Standards transparently to the maximum extent possible in their national and regional standards. Any

divergence between the IEC Standard and the corresponding national or regional standard shall be clearly

indicated in the latter.

5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with one of its standards.

6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject

of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 61952 has been prepared by subcommittee 36B: Insulators for

overhead lines, of IEC technical committee 36: Insulators.
The text of this standard is based on the following documents:
FDIS Report on voting
36B/208/FDIS 36B/209/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.

Annexes A, B, and C are for information only.

The committee has decided that the contents of this publication will remain unchanged until

2004. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
---------------------- Page: 9 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 7 –
INTRODUCTION

Composite line post insulators consist of a cylindrical solid insulating core, bearing the

mechanical load, protected by an elastomer housing, the loads being transmitted to the core

by metal fittings. Despite these common features, the materials used and the construction

details employed by different manufacturers may be different.

Some tests have been grouped together as "design tests" to be performed only once for

insulators of the same design. Design tests are performed in order to eliminate designs and

materials not suitable for high-voltage applications. The influence of time on the electrical and

mechanical properties of the complete composite line post insulator and its components (core

material, housing material, interfaces, etc.) has been considered in specifying the design tests

in order to ensure a satisfactory lifetime under normal service conditions.

The approach for mechanical testing under bending loads used in this standard is based on

the work of CIGRE. This approach uses the concept of a damage limit which is the maximum

stress which can be developed in the insulator before damage begins to occur. Annex A gives

some notes on the mechanical loads and tests used in this standard.

Line post insulators are often used in braced structures whose geometry varies from line to

line. A combined loading test to reproduce the complex loading cases in such structures is

outside the scope of this standard and it would be very difficult to specify a general test which

covers the majority of geometry and loading cases. In order to give some guidance, annex B

explains how to calculate the moment in the insulators resulting from combined loads. This

moment can then be equated to an equivalent bending load or stress for design purposes.

Compression load tests are not specified in this standard. The mechanical loads expected

from service stress acting on line post insulators are mostly combined loads, These loads will

cause some deflection on the insulator. Compression loads applied on pre-deflected

insulators will lead to results largely dependent on the pre-deflection. Therefore a pure

compression test has little meaning since the deflection prior to the cantilever load test cannot

be specified.

Pollution tests, as specified in IEC 60507, are not included in this standard, their applicability

to composite line post insulators not having been proven. Such pollution tests performed on

insulators made of non-ceramic materials do not correlate with experience obtained from

service. Specific pollution tests for non-ceramic insulators are under consideration.

The tracking and erosion test given in this standard is based on the test specified in

IEC 61109. However, when this standard was drafted, it had been decided to study the

possibility of preparing a general standard on tracking, erosion and ageing tests for all types

of composite insulators. The prescriptions concerning the 1 000 h and alternative tests for

severe environmental conditions are therefore given as a temporary measure until such time

as the general standard is issued by the IEC.
---------------------- Page: 10 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 9 –

For insulators intended for use in severe environmental conditions, a supplementary multi-

stress ageing test may be considered (such as the 5 000 h ageing test in annex C of

IEC 61109). However CIGRE and IEC are currently studying the representativity, repeatability

and reproducibility of ageing tests and will issue guidance in the future. In the meantime, it is

recommended that particular care be taken when specifying the type and parameters of such

tests.

It has not been considered useful to specify a power arc test as a mandatory test. The test

parameters are manifold and can have very different values depending on the configurations

of the network and the supports and on the design of arc-protection devices. The heating

effect of power arcs should be considered in the design of metal fittings. Critical damage to

the metal fittings, resulting from the magnitude and duration of the short-circuit current can be

avoided by properly designed arc-protection devices. This standard, however, does not

exclude the possibility of a power arc test if agreed between the user and manufacturer.

IEC 61467 gives details of a.c. power arc testing of insulator sets.

Radio interference and corona tests are not specified in this standard since the RIV and

corona performance are not characteristics of the insulator alone.

Composite, hollow core, line post insulators are currently not dealt with in this standard.

IEC 61462 gives details of tests on hollow core, composite insulators, many of which can be

applied to such line post insulators.

Torsion loads are not dealt with in this standard since they are usually negligible in the

configuration in which line post insulators are generally used. Specific applications where high

torsion loads can occur are outside the scope of this standard.
---------------------- Page: 11 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 11 –
INSULATORS FOR OVERHEAD LINES –
COMPOSITE LINE POST INSULATORS FOR ALTERNATIVE CURRENT
WITH A NOMINAL VOLTAGE >>>>1000 V
1 Scope and object

This International Standard applies to composite line post insulators consisting of a load-

bearing, cylindrical, insulating solid core made up of fibres – usually glass – in a resin-based

matrix, a housing (outside the insulating core) made of elastomer material (e.g. silicone or

ethylene-propylene) and end fittings permanently attached to the insulating core.

Composite line post insulators covered by this standard are subjected to cantilever, tensile

and compressive loads, when supporting the line conductors.

They are intended for use on a.c. overhead lines with a rated voltage greater than 1 000 V

and a frequency not greater than 100 Hz.
The object of this standard is to
– define the terms used,
– prescribe test methods,
– prescribe acceptance or failure criteria.

This standard does not include requirements dealing with the choice of insulators for specific

operating conditions.
2 Normative references

The following referenced documents are indispensable for the application of this document.

For dated references, only the edition cited applies. For undated references, the latest edition

of the referenced document (including any amendments) applies.

IEC 60060-1:1989, High-voltage test techniques – Part 1: General definitions and test

requirements

IEC 60383-1:1993, Insulators for overhead lines with a nominal voltage above 1 000 V –

Part 1: Ceramic or glass insulator units for a.c. systems – Definitions, test methods and

acceptance criteria

IEC 60383-2:1993, Insulators for overhead lines with a nominal voltage above 1 000 V –

Part 2: Insulator strings and insulator sets for a.c. systems – Definitions, test methods and

acceptance criteria

IEC 60695-11-10:1999, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and

vertical flame test methods

ISO 868:1985, Plastics and ebonite – Determination of indentation hardness by means of

a durometer (Shore hardness)
---------------------- Page: 12 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 13 –

ISO 3274:1996, Geometrical Product Specifications (GPS) – Surface texture: Profile method –

Nominal characteristics of contact (stylus) instruments
ISO 3274:1996/Cor. 1:1998
ISO 3452 (all parts), Non-destructive testing – Penetrant inspection

ISO 4287:1997, Geometrical Product Specifications (GPS) – Surface texture: Profile method –

Terms, definitions and surface texture parameters
ISO 4287:1997/Cor. 1:1998

ISO 4892-1:1999, Plastics – Methods of exposure to laboratory light sources – Part 1:

General guidance

ISO 4892-2:1994, Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-

arc sources

ISO 4892-3:1994, Plastics – Methods of exposure to laboratory light sources – Part 3:

Fluorescent UV lamps
3 Definitions

For the purposes of this International Standard, the following definitions apply.

3.1
composite line post insulator

insulator consisting of a load-bearing cylindrical insulating solid core, a housing and end

fittings attached to the insulating core. It is intended to be subjected to cantilever, tensile

and compressive loads
3.2
core

internal insulating part of a composite line post insulator designed to ensure the mechanical

characteristics. The core usually consists of glass-fibres in a resin-based matrix

3.3
housing

external insulating part of composite line post insulator providing necessary creepage

distance and protecting core from environment. An intermediate sheath made of insulating

material may be part of the housing
3.4
housing profile
shape and dimensions of the housing which include the following:
– shed overhang(s)
– shed thickness at the base and at the tip
– shed spacing
– shed repetition
– shed inclination(s).
---------------------- Page: 13 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 15 –
3.5
shed
projecting part of the housing intended to increase the creepage distance
3.6
interface

surface between different materials. Various interfaces occur in most composite line post

insulators, e.g.
– between glass fibres and impregnating resin,
– between core and housing,

– between various parts of the housing, e.g. between sheds or between sheds and sheath,

– between housing, core and end fittings
3.7
end fittings of a composite line post insulator

devices forming an integral and permanent part of the insulator intended to connect it to a

supporting structure or to conductor hardware. The base end fitting of a composite line post

insulator is where the maximum cantilever stress usually occurs. The line end fitting is where

the cantilever load is usually applied
3.8
connection zone

zone where the mechanical load is transmitted between the core and the end fitting

3.9
coupling zone

part of the end fitting which transmits the load to the hardware external to the composite line

post insulator
3.10
tracking

irreversible degradation consisting of the formation of conductive paths starting and

developing on the surface of an insulating material. These paths are conductive even under

dry conditions. Tracking can occur on surfaces in contact with air and also on the interfaces

between different insulating materials
3.11
erosion

irreversible and non-conducting degradation of the surface of the insulator that occurs by loss

of material. This can be uniform, localized or tree-shaped

NOTE Light surface traces, commonly tree-shaped, can occur on composite line post insulators, as on ceramic

insulators, after partial flashover. These traces are not considered to be objectionable as long as they are non-

conducting. When they are conducting they are classed as tracking.
3.12
delamination of the core
irreversible loss of bonding within fibre laminates perceivable by the naked eye
3.13
crack
any internal fracture or surface fissure of depth greater than 0,1 mm
---------------------- Page: 14 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 17 –
3.14
specified cantilever load (SCL)

cantilever load which can be withstood by the insulator at the line end fitting when tested

under the prescribed conditions. This value is specified by the manufacturer
3.15
maximum design cantilever load (MDCL)

load level above which damage to the core begins to occur and which is the ultimate limit for

service loads. This value and direction of the load are specified by the manufacturer

3.16
specified tensile load (STL)

tensile load which can be withstood by the insulator when tested under the prescribed

conditions. This value is specified by the manufacturer
3.17
failing load of a composite line post insulator
maximum load that is reached when tested under the prescribed conditions

NOTE Damage to the core is likely to occur at loads lower than the insulator failing load.

4 Identification

The manufacturer’s drawing shall show the relevant dimensions and values necessary for

identifying and testing the insulator in accordance with this standard. The drawing shall also

show applicable manufacturing tolerances. In addition, the relevant IEC designation shall

figure on the drawing.

Each insulator shall be marked with the name or trade mark of the manufacturer and the year

of manufacture. In addition, each insulator shall be marked with the MDCL or with the relevant

IEC designation. These markings shall be legible and indelible.

NOTE At present there is no IEC standard giving designations of composite line post insulators.

5 Classification of tests
The tests are divided into four groups as follows:
5.1 Design tests

These tests are intended to verify the suitability of the design, materials and method of

manufacture (technology). A composite line post insulator design is defined by
− materials of the core, housing and manufacturing method,
− material of the end fittings, their design and method of attachment,
− layer thickness of the housing over the core (including a sheath where used),
− diameter of the core.

When changes in the design occur, re-qualification shall be carried out in accordance with

table 1.
---------------------- Page: 15 ----------------------
SIST EN 61952:2004
61952  IEC:2002 – 19 –
Table 1 – Tests to be carried out after design changes
THEN the following design tests shall be repeated:
6.2 6.3 6.4.1 6.4.2 6.4.3 6.4.4 6.5.1 6.5.2
IF the change in insulator design concerns: ...
1 Hous
...