EN 60168:1994

SLOVENSKI STANDARD
01-november-1997
Tests on indoor and outdoor post insulators of ceramic material or glass for
systems with nominal voltages greater than 1000 V (IEC 168:1994)
Tests on indoor and outdoor post insulators of ceramic material or glass for systems with
nominal voltages greater than 1 kV
Prüfungen an Innenraum- und Freiluft-Stützisolatoren aus keramischem Werkstoff oder
Glas für Systeme mit Nennspannungen über 1 kV
Essais des supports isolants d'intérieur et d'extérieur, en matière céramique ou en verre,
destinés à des installations de tension nominale supérieure à 1 kV
Ta slovenski standard je istoveten z: EN 60168:1994
ICS:
29.080.10 Izolatorji Insulators
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
INTERNATIONAL
Quatrième édition
STANDARD
Fourth edition
1994-11
Essais des supports isolants d'intérieur et
d'extérieur, en matière céramique ou en verre,
destinés à des installations de tension nominale
supérieure à 1 000 V
Tests on indoor and outdoor post insulators
of ceramic material or glass for systems with
nominal voltages greater than 1 000 V
réservés— Copyright — all rights reserved
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– 3 –
168©IEC:1994
CONTENTS
Page
FOREWORD 7
INTRODUCTION 9
Section 1: General
Clause
11 1.1 Scope and object
1.2 Normative references
1.3 Definitions
Section 2: Insulators
2.1 Insulator designs and insulating materials
2.2 Values which characterize a post insulator 19
2.3 Identification of insulators
Section 3: Classification of the tests, sampling rules and procedures
3.1 Classification of the tests
3.2 Quality assurance
3.3 General requirements for type tests
27 3.4 General requirements for sample tests
Section 4: Test procedures for electrical tests
General requirements for high-voltage tests 29
4.1
4.2 Standard atmospheric conditions and correction factors for electrical tests
4.3 Artificial rain parameters for wet tests
4.4 Mounting arrangements for electrical tests
4.5 Dry lightning-impulse withstand voltage test – Type test
37 4.6 Dry or wet switching-impulse withstand voltage tests – Type test
4.7 Dry power-frequency withstand voltage test – Type test
(applicable only to post insulators for indoor use)
4.8 Wet power-frequency withstand voltage test – Type test
(applicable only to post insulators for outdoor use)
4.9 Puncture test – Sample test
4.10 Routine electrical test
168 ©IEC:1994 — 5
Page
Clause
Section 5: Test procedures for mechanical and other tests
45 Verification of the dimensions — Type and sample test
5.1
5.2 Mechanical failing load test — Type and sample test
53 5.3 Test for deflection under load — Special type test
5.4 Temperature cycle test — Sample test
Routine thermal shock test (applicable only to toughened glass insulating parts)
5.5
Porosity test — Sample test (applicable only to ceramic post insulators)
5.6
5.7 Galvanizing test — Sample test
5.8 Routine visual inspection
5.9 Routine mechanical test
Section 6: Tests applicable to post insulators
6.1 Type tests 69
6.2 Sample tests 69
Routine tests 6.3
71 6.4 Summary of tests on post insulators
Figures
Annexes
Methods of testing for tolerances of parallelism, eccentricity, angular deviations,
A
camber and shed angle of post insulators 79
85 Methods of routine testing of unassembled insulator units
B
C Bibliography 91
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168 ©IEC:1994
INTERNATIONAL ELECTROTECHNICAL COMMISSION
TESTS ON INDOOR AND OUTDOOR POST INSULATORS
OF CERAMIC MATERIAL OR GLASS FOR SYSTEMS
WITH NOMINAL VOLTAGES GREATER THAN 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 cooperation 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, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, 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.
International Standard IEC 168 has been prepared by sub-committee 36C, Insulators for
substations, of IEC technical committee 36: Insulators.
This fourth edition cancels and replaces the third edition published in 1988 and constitutes
a technical revision.
The text of this standard is based on the following documents:
DIS Report on voting
36C(CO)60
36C(CO)58
Full information on the voting for the approval of this standard can be found in the repo rt
on voting indicated in the above table.
Annexes A, B and C are for information only.

168©IEC:1994 -9-
INTRODUCTION
The main purpose in preparing this edition has been to align the text and presentation as
far as practicable with the fourth edition of IEC 383-1 and IEC 383-2.
Concepts of electrical and mechanical equivalence of post insulators have been
introduced, and the clauses dealing with mechanical testing have been redrafted to clarify
the test requirements.
168 ©IEC:1994 - 11 -
TESTS ON INDOOR AND OUTDOOR POST INSULATORS
OF CERAMIC MATERIAL OR GLASS FOR SYSTEMS
WITH NOMINAL VOLTAGES GREATER THAN 1 000 V
Section 1: General
1.1 Scope and object
This International Standard IEC 168 is applicable to post insulators and post insulator
units of ceramic material or glass, for indoor and outdoor use in electrical installations or
equipment, operating on alternating current with a nominal voltage greater than 1 000 V
and a frequency not greater than 100 Hz.
This standard may be regarded as a provisional standard for post insulators for use on
d.c. systems. IEC 438 gives general guidance for those insulators.
This standard does not apply to composite insulators, or to those indoor post insulators in
organic materiel which are covered by another IEC standard [1]*.
The object of this standard is to define:
- the terms used;
- the electrical and mechanical characteristics of post insulators;
the conditions under which the specified values of these characteristics are verified;
-
the methods of test;
-
the acceptance criteria.
Numerical values of characteristics of post insulators are specified in IEC 273.
This standard does not include requirements dealing with the choice of post insulators for
specific operating conditions.
NOTES
1 A guide for the choice of insulators under polluted conditions is available, see [2].
This standard does not include radio interference tests or artificial pollution tests. These subjects and
relevant test methods are dealt with in other IEC publications, see [3], [4] and [5].
3 When this standard is applied to hollow post insulators, other IEC publications should also be taken
into account, see [6] and [7].
The figures in square brackets refer to annex C (Bibliography).

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168 ©IEC:1994
1.2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this International Standard. At the time of publication, the
editions indicated were valid. All normative documents are subject to revision, and pa rties
to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent edition of the normative documents listed below.
Members of IEC and ISO maintain registers of currently valid normative documents.
International Electrotechnical Vocabulary (lEV) - Chapter 471:
IEC 50(471): 1984,
Insulators
High-voltage test techniques - Part 1: General definitions and test
IEC 60-1: 1989,
requirements
Insulation co-ordination - Part 1: Definitions, principles and rules
IEC 71-1: 1993,
Insulation co-ordination - Part 2: Application guide
IEC 71-2: 1976,
Insulation co-ordination - Part 3: Phase-to-phase insulation co-ordination.
IEC 71-3: 1982,
Principles, rules and application guide
IEC 273: 1990, Characteristics of indoor and outdoor post insulators for systems with
nominal voltages greater than 1 000 V
Tests and dimensions for high-voltage d.c. insulators
IEC 438: 1973,
Metallic coatings - Protection against corrosion by hot dip galvanizing -
ISO 1459: 1973,
Guiding principles
Metallic coatings - Hot dip galvanized coatings on ferrous metals -
ISO 1460: 1992,
Gravimetric determination of the mass per unit area
Metallic coatings - Hot dip galvanized coatings on fabricated ferrous
ISO 1461: 1973,
products - Requirements
ISO 1463: 1982, Metal and oxide coatings - Measurement of coating thickness -
Microscopical method
Metallic and other non-organic coatings - Definitions and conventions
ISO 2064: 1980,
concerning the measurement of thickness
Non-magnetic coatings on magnetic substrates - Measurement of coating
ISO 2178: 1982,
thickness - Magnetic method
1.3 Definitions
For the purposes of this standard, the following definitions apply.
The definitions given below are those which either do not appear in IEC 50(471), or differ
from those given in IEC 50(471).

168 ©I EC:1994 - 15 -
term "insulator" is used in this standard to refer to the object being
1.3.1 insulator: The
tested. Unless otherwise specified, this refers to an assembled post insulator, complete
with metal fittings. In this standard, the term "post insulator" shall be taken to mean post
insulator, or post insulator unit, as required by the text.
NOTES
The term "approximately cylindrical shape" covers a unit of circular cross-section, which may vary in
diameter.
For indoor installations subject to excessive condensation, outdoor post insulators, or special indoor
post insulators may be used.
1.3.2 lot: A group of insulators offered for acceptance from the same manufacturer, of
the same design and manufactured under similar conditions of production. One or more
lots may be offered together for acceptance; the lot(s) offered may consist of the whole, or
part, of the quantity ordered.
lightning-impulse voltage which the
1.3.3 d ry lightning-impulse withstand voltage: The
under the prescribed conditions of test.
post insulator withstands d ry ,
The value of the lightning-impulse
1.3.4 50 % dry lightning impulse flashover voltage:
voltage which, under the prescribed conditions of test, has a 50 % probability of producing
flashover on the post insulator, dry.
NOTE — The term "flashover" used in this standard includes flashover across the insulator surface as well
as disruptive discharges by sparkover through air adjacent to the insulator. Disruptive discharges should
only occur occasionally elsewhere (for instance, to other structures or to earth), in which event they should
not be taken into account for the purpose of this standard.
switching-impulse voltage
or wet switching-impulse withstand voltage: The
1.3.5 d ry
which the post insulator withstands, dry or wet respectively, under the prescribed
conditions of test.
The value of the switching-
50 % dry or wet switching-impulse flashover voltage:
1.3.6
impulse voltage which, under the prescribed conditions of test, has a 50 % probability of
producing flashover on the post insulator, dry or wet respectively.
voltage
1.3.7 dry or wet power-frequency withstand voltage: The power-frequency
which the post insulator withstands dry or wet respectively, under the prescribed
conditions of test.
The arithmetic mean value of the
1.3.8 dry or wet power-frequency flashover voltage:
measured voltages which cause flashover on the post insulator, dry or wet respectively,
under the prescribed conditions of test.
The voltage which causes puncture of a post insulator under the
1.3.9 puncture voltage:
prescribed conditions of test.
The maximum load reached when a post insulator is
1.3.10 mechanical fail
...