BS EN 60168:1995

Foreword
Introduction
Section 1. General
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
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
3.4 General requirements for sample tests
Section 4. Test procedures for electrical tests
4.1 General requirements for high-voltage tests
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
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
Section 5. Test procedures for mechanical and other tests
5.1 Verification of the dimensions - Type and sample test
5.2 Mechanical failing load test - Type and sample test
5.3 Test for deflection under load - Special type test
5.4 Temperature cycle test - Sample test
5.5 Routine thermal shock test (applicable only to
     toughened glass insulating parts)
5.6 Porosity test - Sample test (applicable only to
     ceramic post insulators)
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
6.2 Sample tests
6.3 Routine tests
6.4 Summary of tests on post insulators
Annex A (informative) Methods of testing for tolerances
        of parallelism, eccentricity, angular deviation,
        camber and shed angle of post insulators
Annex B (informative) Methods of routine testing of
        unassembled insulator units
Annex C (informative) Bibliography
Annex ZA (normative) Other international publications
         quoted in this standard with the references of
         the relevant European publications

This standard applies only to a.c. applications and not to composite and/or organic material insulators.

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 material which are covered by another IEC standard [1]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.

NOTE 1 A guide for the choice of insulators under polluted conditions is available, see [2].

NOTE 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].

NOTE 3 When this standard is applied to hollow post insulators, other IEC publications should also be taken into account, see [6] and [7].