TC 36 - Insulators

IEC/TR 62730:2012(E) is applicable to polymeric insulators whose insulating body consists of one or various organic materials. Polymeric insulators covered by this technical report include both solid core and hollow insulators. They are intended for use on overhead lines and in indoor and outdoor equipment with a rated voltage greater than 1 000 V. The object of this technical report is:
- to define the common terms used;
- to give the background behind the development and use of the 5 000 h multiple stress test and the tracking wheel test;
- to describe the test methods for the 5 000 h multiple stress test and the tracking wheel tests on polymeric insulators;
- to describe possible acceptance or failure criteria, if applicable. Key words: polymeric insulators, multiple stress test, 5000 h

IEC 62896:2024 applies to hybrid insulators for AC and DC applications greater than 1 000 V AC and 1 500 V DC consisting of a load-bearing insulating solid or hollow core consisting of ceramic or glass, a housing (defined geometry, outside the insulating core) made of polymeric material and end fittings permanently attached to the insulating core.
Hybrid insulators covered by this document are intended for use as suspension/tension long rod and cap and pin type insulators, line post insulators, station post insulators and hollow core insulators for apparatus.
The object of this document is to:
- define the terms used;
- prescribe test methods;
- prescribe acceptance criteria
This document does not include requirements dealing with the choice of insulators for specific operating conditions. This first edition cancels and replaces the IEC TS 62896 published in 2015. This edition includes the following significant technical changes with respect to the previous edition:
- modifications of terms and definitions;
- modifications of tests procedures included in IEC TR 62039 and IEC 62217 (Hydrophobicity transfer test);
- harmonization of Table 1 (Tests to be carried out after design and type changes) with other product standards and IEC 62217.

IEC 60437:2023 specifies the procedure for a radio interference (RI) test carried out in a laboratory on clean and dry insulators at a frequency of 0,5 MHz or 1 MHz or, alternatively, at other frequencies between 0,5 MHz and 2 MHz.
This document applies to insulators for use on AC or DC overhead power lines and overhead traction lines with a nominal voltage greater than 1 000 V.
This third edition cancels and replaces the second edition published in 1997. This third edition cancels and replaces the second edition published in 1997. This edition includes the following significant technical changes with respect to the previous edition:
a) Composite station post and composite hollow core station post insulators have been included;
b) All paragraphs of Samples test were actualized;
c) Sample test fast procedure was introduced.

IEC 62772:2023 applies to composite hollow core station post insulators consisting of a load-bearing insulating tube (core) made of resin impregnated fibres, insulating filler material (solid, liquid, gaseous – pressurized or unpressurized), a housing (outside the insulating tube) made of polymeric material (for example silicone or ethylene-propylene) and fixing devices at the ends of the insulating tube. Composite hollow core station post insulators as defined in this standard are intended for general use in substations in both, outdoor and indoor environments, operating with a rated AC voltage greater than 1 000 V and a frequency not greater than 100 Hz or for use in direct current systems with a rated voltage greater than 1 500 V DC. The object of this document is:
- to define the terms used;
- to specify test methods;
- to specify acceptance criteria.

IEC 61462:2023 applies to composite hollow insulators consisting of a load-bearing insulating tube made of resin-impregnated fibres, a housing (outside the insulating tube) made of elastomeric material (for example silicone or ethylene-propylene) and metal fixing devices at the ends of the insulating tube (see Figure D.1 and Figure D.2 for examples). The object of this document is to define the terms used, to specify test methods; and to specify acceptance criteria. This document distinguishes between design tests and type tests because several general characteristics of a specific design and specific combinations of materials do not vary for different insulator types. This new edition cancels and replaces the previous edition published in 2007. This edition includes the following significant technical changes with respect to the previous edition:
a) modifications of terms and definitions;
b) modifications of tests procedures included in IEC TR 62039 and IEC 62217 (Hydrophobicity transfer test; Water diffusion test on the core with housing);
c) modification of Clause 8 (type tests) to reflect common practice and to also consider tapered (conical) insulators;
modification of order of the stages of mechanical sample test (9.4) by setting the tightness test as last stage;
d) harmonization of Table 3 (Tests to be carried out after design changes) with other product standards;
e) addition of a new informative Annex D: Principle sketch of hollow insulators design assembly;
f) addition of a new informative Annex E: Type tests on tapered (conical) insulators.

IEC 60383-1:2023 applies to insulators of ceramic material or glass for use on AC overhead power lines and overhead traction lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It also applies to insulators for use on DC overhead electric traction lines. This document applies to string insulator units, rigid overhead line insulators and to insulators of similar design when used in substations. lt does not apply to insulators forming parts of electrical apparatus or to parts used in their construction or to post insulators which are covered by IEC 60168, Tests on indoor and outdoor post insulators of ceramic material or glass for systems with nominal voltages greater than 1 000 V.
The object of this document is:
- to define the terms used
- to define insulator characteristics and to prescribe the conditions under which the specified values of these characteristics shall be verified
- to prescribe test methods
- to prescribe acceptance criteria.
This fifth edition cancels and replaces the fourth edition published in 1993. This edition includes the following significant technical changes with respect to the previous edition:
a) The layout of the document has been changed in order to increase readability;
b) RIV test has been added (Clause 14);
c) Impulse puncture test in air has been added (15.2);
d) Residual strength test has been added (Clause 21);
e) Zinc sleeve test has been added (Clause 28);
f) Impact test has been added (Clause 30);
g) Annex C, coatings on ceramic and glass insulators has been added;
h) Annex D, impact test has been added.

IEC 60433:2021 is applicable to string insulator units of the long rod type with insulating parts of ceramic material intended for use in AC overhead power lines with a nominal voltage greater than 1000 V and a frequency not greater than 100 Hz. It is also applicable to insulators of similar design, used in substations. This document is applicable to ceramic string insulator units of the long rod type, either with a clevis end fitting at both ends for coupling with a tongue, or with a socket end fitting at both ends for coupling with a pin ball. The object of this document is to prescribe specified values for electrical and mechanical characteristics, and for the principal dimensions of ceramic string insulator units of the long rod type. This fourth edition cancels and replaces the third edition published in 1998. This edition includes the following significant technical changes with respect to the previous edition:
- wording in Scope changed from "should" to "are intended to";
- new normative references added;
- title of Clause 4 amended, new Note 4 added;
- Table 1 expanded to include more specified mechanical failing loads.

IEC 60305:2021 applies to string insulator units of the cap and pin type with insulating parts of ceramic material or glass, intended for AC overhead lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It also applies to insulators of similar design used in substations. This document applies to string insulator units of the cap and pin type either with ball and socket couplings or with clevis and tongue couplings. This document applies to string insulator units for use on overhead lines in clean areas and polluted areas. For use in areas characterized by very heavy pollution levels and for other particular or extreme environmental conditions, it may be necessary for certain dimensions to be changed and insulator units having different creepage distances, spacing and forms may be preferred (for example, flat profile, hemispherical etc.). Insulators for use on DC systems may also need different dimensions. In any case, it is applicable that the standardized mechanical characteristics of this document and coupling sizes are retained. This fifth edition cancels and replaces the fourth edition published in 1995. This edition includes the following significant technical changes with respect to the previous edition:
- wording in Scope changed from "it is recommended" to "it is applicable";
- new normative references added;
- electromechanical or mechanical failing load in Clause 4 specified;
- new figures added showing profiles.

IEC 60372:2020 is applicable to locking devices used with ball and socket couplings of string insulator units and used with the corresponding metal fittings standardized in IEC 60120, when they are supplied separately.The object of this document is
- to define the shapes and some standard dimensions for locking devices,
- to define the test methods for locking devices,
- to state the acceptance conditions for supply,
- to give other dimensions for guidance of manufacturing only.
This fourth edition cancels and replaces the third edition published in 1984. This edition includes the following significant technical changes with respect to the previous edition:
a. Two new designated size of couplings, 36 and 40, were introduced;
b. the relevant content of the 28B W-clip was deleted;
c. Annex A is informative, Annex B is normative, Annex C is informative.

IEC 60120:2020 define the dimensions of a series of standard ball and socket couplings using the standard locking devices (see IEC 60372) in order to permit the assembly of insulators or metal fittings supplied by different manufacturers. This document applies to string insulator units of the cap and pin and long rod types and their associated metal fittings. For the pin ball and the socket, dimensions apply to the finished product after any surface treatment. Extreme positions of the pin ball in the socket are given in annex. Typical examples of gauges for checking the dimensions of pin balls and sockets are given in annex.

IEC 60471:2020 applies to string insulator units of the cap and pin type and also of the long rod type as well as the fittings used with such insulators. The object of this document is to define the dimensions of a series of clevis and tongue couplings to permit the assembly of insulators or fittings supplied by different manufacturers.
This third edition cancels and replaces the second edition published in 1977. This edition includes the following significant technical changes with respect to the previous edition:
- there are no new clevis and tongue couplings;
- For the dimensions of the existing designated size of couplings that characterize the same location, the effective number of the size is unified.

IEC 61952-1:2019 is applicable to composite line post insulators for AC overhead lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It also applies to line post insulators of similar design used in substations or on electric traction lines.
This document applies to line post insulators of composite type, generally with metallic couplings, with and without a base plate. It also applies to such insulators when used in complex structures. It does not apply to hollow insulators adapted for use as line post insulators
The object of this document is to specify the main dimensions of the couplings to be used on the composite line post insulators in order to permit the assembly of insulators or fittings supplied by different manufacturers and to allow, whenever practical, interchangeability with existing installations. It also specifies a standard designation system for composite line post insulators.

IEC 60137:2017 specifies the characteristics and tests for insulated bushings.
This standard is applicable to bushings, as defined in Clause 3, intended for use in electrical apparatus, machinery, transformers, switchgear and installations for three-phase alternating current systems, having highest voltage for equipment above 1 000 V and power frequencies of 15 Hz up to and including 60 Hz.
Subject to special agreement between purchaser and supplier, this standard may be applied, in part or as a whole, to the following:
- bushings used in other than three-phase systems;
- bushings for high-voltage direct current systems;
- bushings for testing transformers;
- bushings for capacitors.
Special requirements and tests for transformer bushings in this standard apply also to reactor bushings.
This standard is applicable to bushings made and sold separately. Bushings which are a part of an apparatus and which cannot be tested according to this standard should be tested with the apparatus of which they form part. This edition includes the following significant technical changes with respect to the previous edition:
- Resin-impregnated synthetic (RIS) bushings has been introduced.
- Bushings with Um ≤ 1,1 kV, Um = 1100 kV and Um = 1200 kV have been introduced.
- Temperature rise testing has been included for liquid-insulated bushings according to clause to 3.4.
- Introducing dry lightning impulse testing as a routine test for all transformer bushings with Um > 72,5 kV.
- The altitude correction procedure has been revised ( > 1 000 m).
- An explanation about Very Fast Transient (VFT) phenomenon and its impact on bushings has been included.
The contents of the corrigendum of May 2018 have been included in this copy.

IEC TS 60815-4:2016(E) which is a Technical Specification, is applicable as first approach for the determination of the required d.c. Unified Specific Creepage Distance for insulators with respect to pollution. To avoid excessive over or under design, existing operation experience should be compared and eventually additional appropriate tests may be performed by agreement between supplier and customer. It is applicable to:
- Glass and porcelain insulators;
- Composite and hybrid insulators with an HTM or non-HTM housing. This part of IEC 60815 gives specific guidelines and principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments.

IEC 62772:2016 applies to composite hollow core station post insulators consisting of a load-bearing insulating tube (core) made of resin impregnated fibres an insulating filler material (e.g. solid, liquid, foam, gaseous pressurized or unpressurized), a housing (outside the insulating tube) made of polymeric material (for example silicone or ethylene-propylene) and metal fixing devices at the ends of the insulating tube. Composite hollow core station post insulators as defined in this standard are intended for general use in substations in both, outdoor and indoor environments, operating with a rated AC voltage greater than 1 000 V and a frequency not greater than 100 Hz or for use in direct current systems with a rated voltage greater than 1 500 V. The object of this standard is:
- to define the terms used;
- to prescribe test methods;
- to prescribe acceptance criteria.
All the tests in this standard, apart from the thermal-mechanical test, are performed at normal ambient temperature. This standard does not prescribe tests that may be characteristic of the apparatus of which the composite hollow core station post insulator ultimately may form a part.

IEC TS 61463:2016(E), which is a Technical Specification, is applicable to alternating current and direct current bushings for highest voltages above 52 kV (or with resonance frequencies placed inside the seismic response spectrum), mounted on transformers, other apparatus or buildings. For bushings with highest voltages less than or equal to 52 kV (or with resonance frequencies placed outside from the seismic response spectrum), due to their characteristics, seismic qualification is not used as far as construction practice and seismic construction practice comply with the state of the art. This document presents acceptable seismic qualification methods and requirements to demonstrate that a bushing can maintain its mechanical properties, insulate and carry current during and after an earthquake. The seismic qualification of a bushing is only performed upon request.

IEC 61466-1:2016 is applicable to composite string insulator units for a.c. overhead lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It also applies to insulators of similar design used in substations or on electric traction lines. This standard applies to string insulator units of composite type with ball, socket, tongue, clevis, Y-clevis or eye couplings, or a combination thereof. The object of this standard is to prescribe specified values for the mechanical characteristics of the composite string insulator units and define the main dimensions of the couplings to be used on the composite string insulator units in order to permit the assembly of insulators or fittings supplied by different manufacturers and to allow, whenever practical, interchangeability with existing installations. It also defines a standard designation system for composite string insulator units. This edition includes the following significant technical changes with respect to the previous edition:
a) Addition of strength classes reflecting UHV practice;
b) Inclusion of Corrigendum 1:2008 for Y fitting hole dimensions.

IEC TS 62073:2016(E) specifies the measurement of the hydrophobicity of the shed and housing material of composite insulators for overhead lines, substations and equipment or ceramic insulators covered or not covered by a coating. The obtained value represents the hydrophobicity at the time of the measurement. The object of this technical specification is to describe three methods that can be used to determine the hydrophobicity of insulators. The determination of the ability of water to wet the surface of insulators may be useful to evaluate the condition of the surface of insulators in service, or as part of the insulator testing in the laboratory. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) Changed wettability to hydrophobicity throughout the document
b) Redefined the criteria for the determination of hydrophobicity class in paragraph 3.4.

IEC 62231-1:2015 specifies main dimensions and values for mechanical and electrical characteristics of composite station post insulators.

IEC TS 61245:2015(E) is applicable for the determination of the d.c. withstand characteristics of ceramic and glass insulators to be used outdoors and exposed to polluted atmospheres, on d.c. systems with the highest voltage of the system greater than +/- 1 000 V. These tests are not applicable to polymeric insulators, to greased insulators or to special types of insulators (e.g. insulators with semiconducting glaze or covered with any organic insulating material). The object of this technical specification is to prescribe procedures for artificial pollution tests applicable to insulators for overhead lines, substations and traction lines and to bushings. This second edition cancels and replaces the first edition published in 1993. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) Corrections and the addition of explanatory material;
b) The addition of Clause 4.4.2 on atmospheric correction;
c) The change of upper limit of volume conductivity of tap water for insulator cleaning to 0,1 S/m;
d) The extension to UHV voltages; and
e) The addition of Annex B "Determination of the withstand characteristics of insulators" and Annex E "Supplementary information on artificial pollution tests on insulators for voltage systems of +/- 600 kV and above (solid layer method procedure B).
The contents of the corrigendum of August 2018 have been included in this copy.

IEC/IEEE 65700-19-03:2014 applies to outdoor and indoor bushings of any voltage used on DC systems, of capacitance graded or gas insulated types for use as components of oil-filled converter transformers and smoothing reactors, as well as air-to-air DC bushings. This standard makes reference to IEC 60137 for general terms and conditions and defines the special terms used, operating conditions, ratings, test procedures as well as general mechanical and electrical requirements for bushings for DC application. This standard replaces IEC 62199:2004, Bushings for DC application.

IEC 60507:2013 is applicable for the determination of the power frequency withstand characteristics of ceramic and glass insulators to be used outdoors and exposed to polluted atmospheres, on a.c. systems with the highest voltage of the system greater than 1 000 V. These tests are not directly applicable to polymeric insulators, to greased insulators or to special types of insulators (insulators with semiconducting glaze or covered with any organic insulating material). The object of this International Standard is to prescribe procedures for artificial pollution tests applicable to insulators for overhead lines, substations and traction lines and to bushings. It may also be applied to hollow insulators with suitable precautions to avoid internal flashover. In applying these procedures to apparatus incorporating hollow insulators, the relevant technical committees should consider their effect on any internal equipment and the special precautions which may be necessary. This edition includes the following significant technical changes with respect to the previous edition:
a) Corrections and the addition of explanatory material;
b) The addition of Clause 4.3.2 on atmospheric correction;
c) The change of the upper limit of conductivity of water to 0.1 S/m; and
d) The extension to UHV voltages.
The contents of the corrigendum of August 2018 have been included in this copy.

IEC 62217:2012 is applicable to polymeric insulators whose insulating body consists of one or various organic materials. Polymeric insulators covered by this standard include both solid core and hollow insulators. They are intended for use on HV overhead lines and in indoor and outdoor equipment. The object of this standard is:
- to define the common terms used for polymeric insulators;
- to prescribe common test methods for design tests on polymeric insulators;
- to prescribe acceptance or failure criteria, if applicable.
These tests, criteria and recommendations are intended to ensure a satisfactory life-time under normal operating and environmental conditions. This standard shall only be applied in conjunction with the relevant product standard. This second edition cancels and replaces the first edition published in 2005. This edition constitutes a technical revision. This edition includes a significant technical change with respect to the previous edition. The first edition of IEC 62217 (2005) included two other alternative tracking and erosion tests (a 5 000 hour multi-stress test and a tracking wheel test) which were based on tests developed by CIGRE and utilities. These tests are no longer given as normative alternatives following the results of a study/questionnaire by TC 36 on the relative merits of all three tracking and erosion tests. The 5 000 hour multi-stress test and a tracking wheel test are described in IEC/TR 62730 (2012).

IEC/TR 62662:2010(E) presents an analysis of the risk of influencing factors for brittle fracture of composite insulators that are mostly loaded in the tensile mode (suspension and tension insulators). Guidance is given to reduce the risk of in-service brittle fractures.

IEC/TS 60815-2:2008(E) is applicable to the selection of ceramic and glass insulators for a.c. systems, and the determination of their relevant dimensions, to be used in high-voltage systems with respect to pollution. This part of IEC 60815 gives specific guidelines and principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments. This first edition of IEC/TS 60815-2, together with IEC/TS 60815-1, cancels and replaces IEC/TR 60815, which was issued as a technical report in 1986.

IEC/TS 80815-1:2008(E) applies to the selection of insulators, and the determination of their relevant dimensions, to be used in high-voltage systems with respect to pollution. This part of IEC 60815 gives general definitions, methods for the evaluation of pollution site severity (SPS) and outlines the principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments. This first edition of IEC/TS 60815-1 cancels and replaces IEC/TR 60815, which was issued as a technical report in 1986.

IEC/TS 60815-3:2008(E) is applicable to the selection of polymer insulators for a.c. systems, and the determination of their relevant dimensions, to be used in high voltage systems with respect to pollution. This part of IEC/TS 60815 gives specific guidelines and principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments.

IEC 61467:2008 applies to insulator strings and sets comprising string insulator units of ceramic material, glass or composite material for use on a.c. overhead lines and traction lines with a nominal voltage above 1 000 V and a frequency between 15 Hz and 100 Hz. This standard also applies to insulator strings or sets of similar design used in substations. This standard establishes a standard test procedure for power arc tests on insulator sets. It also establishes a standard test procedure for power arc tests on short strings. This standard does not apply to insulator sets mounted on non-metallic poles or towers. This edition cancels and replaces IEC/TR 61467, which was published as a technical report in 1997. It constitutes a technical revision and now has the status of an International Standard.

IEC 60137:2008 gives the characteristics and tests for insulated bushings intended for use in electrical apparatus, machinery, transformers, switchgear and installations for three-phase alternating current systems, having highest voltage for equipment above 1 000 V and power frequencies of 15 Hz up to and including 60 Hz. Special requirements and tests for transformer bushings in this standard apply also to reactor bushings. This edition includes the following significant technical changes with respect to the previous edition:
- Long duration power-frequency for transformer bushings;
- Special requirements for type and acceptance tests applicable to transformer and GIS bushings;
- Specific insulation levels for bushings fitted to transformers and GIS;
- According to IEC Guide 111, clauses relating to safety and the environment have been added; and
- The altitude correctino procedure has been revised (> 1 000 m).

IEC 61109:2008 applies to composite suspension/tension insulators consisting of a load-bearing cylindrical insulating solid core consisting of fibres - usually glass - in a resin-based matrix, a housing (outside the insulating core) made of polymeric material and end fittings permanently attached to the insulating core. The main technical changes with respect to the previous edition are
- removal of tests procedures now given in IEC 62217;
- inclusion of clauses on tolerances, environmental conditions, transport, storage and installation;
- general improvement of the description of tests and addition of a new Annex C on non-standard loads.

IEC 61952:2008 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. This edition includes the following significant technical changes with respect to the previous edition:
- removal of tests procedures now given in IEC 62217;
- inclusion of clauses on tolerances, environmental conditions, transport, storage and installation;
- changes in the parameters determining the need to repeat design and type tests; and
- modification of the specification of load application in bending tests to simplify testing.

IEC/TS 62371:2008(E) is a Technical Specification which applies to ceramic and glass hollow insulators intended for general use in electrical equipment; and ceramic hollow insulators intended for use with a permanent gas pressure in switchgear and controlgear. This specification specifies the dimensional and mechanical characteristics of the hollow insulator, which are essential for interchangeability of the hollow insulator of the same type. It is not the object of this specification to prescribe electrical characteristics because they are dependent on the apparatus of which the hollow insulator ultimately forms a part. However, standard lightning impulse withstand voltage which is provided in IEC 60071-1 is described only for reference for classification purpose. This specification applies to hollow insulators for use in electrical equipment in clean areas or lightly polluted areas, where seismic qualification is not required.

This International Standard applies to composite hollow insulators consisting of a load-bearing insulating tube made of resin impregnated fibres, a housing (outside the insulating tube) made of elastomeric material (for example silicone or ethylene-propylene) and metal fixing devices at the ends of the insulating tube. The object of this standard is: To define the terms used; to prescribe test methods; and to prescribe acceptance criteria.

This International Standard applies to composite station post insulators consisting of a load bearing cylindrical insulating solid core made of resin impregnated fibres, a housing (outside the insulating solid core) made of elastomer material (e.g. silicone or ethylene-propylene) and end fittings attached to the insulating core. Composite station post insulators covered by this standard are subjected to cantilever, torsion, tension and compression loads. They are intended for substations with a.c. voltages greater than 1 000 V up to 245 kV.

This International Standard is applicable to polymeric insulators whose insulating body consists of one or various organic materials. Polymeric insulators covered by this standard include both solid core and hollow insulators. They are intended for use on overhead lines and in indoor and outdoor equipment with a rated voltage greater than 1 000 V.

Deals with impulse puncture testing in air of ceramic and glass insulator units of class B: cap and pin, pin type (including pin-post type) and class B long rod insulators. May be applied also in tests on Class B insulators of other materials (e.g. polymers and composites). However, it may be useful to consider the possible need to adjust the test procedure accordingly.

Specifies the characteristics and tests for insulated bushings intended for use in electrical apparatus, machinery, transformers, switchgear and installations for three-phase alternating current systems, having highest voltage for equipment above 1 000 V and power frequencies of 15 Hz up to and including 60 Hz. Special requirements and tests for transformer bushings in this standard apply also to reactor bushings.

The methods described in this technical specification can be used for the measurement of the wettability of the shed and housing material of composite insulators for overhead lines, substations and equipment or ceramic insulators covered or not covered by a coating. The obtained value represents the wettability at the time of the measurement. The determination of the ability of water to wet the surface of insulators may be useful to evaluate the condition of the surface of insulators in service, or as part of the insulator testing in the laboratory.

Applicable to ceramic and glass hollow insulators intended for general use in electrical equipment and ceramic hollow insulators intended for use with a permanent gas pressure in switchgear and controlgear. These insulators are intended for indoor and outdoor use in electrical equipment, operating on alternating current with a rated voltage greater than 1 000 V and a frequency not greater than 100 Hz or for use in direct-current equipment with a rated voltage of greater than 1 500 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.

Is applicable to composite string insulators with a specified mechanical load (SML) of 40 kN and 70 kN for a.c. overhead distribution lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It also applies to insulators of similar design used in substations or on electric traction lines. This consolidated version consists of the first edition (1998) and its amendment 1 (2002). Therefore, no need to order amendment in addition to this publication.

Applies to post insulators and post insulator units of ceramic material or glass for indoor and outdoor service 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. Notes: -May also be regarded as a provisional standard for insulators for use on d.c. systems, see IEC 60438. -When considering hollow insulators, see IEC 60233. -Tests on indoor post insulators of organic material will be covered by a future publication: Tests on indoor post insulators of organic material for systems with nominal voltages greater than 1 000 V up to but not including 300 kV. -For artificial pollution and radio-interference tests, see IEC 60437 and 60507. -For numerical values for insulator characteristics and for selection of insulators for specific operating conditions, see IEC 60273.