TC 36 - Insulators

IEC TS 63414:2025 is applicable for the determination of the AC and DC pollution flashover and withstand voltage characteristics of insulators with polymeric housing, to be used outdoors in HV applications and exposed to polluted environments. This is also applicable for insulators with hydrophobic coatings. This document refers to AC systems with a rated voltage greater than 1 000 V and DC systems with a rated voltage greater than 1 500 V.
The object of this technical specification is to prescribe standardized test methods, requirements and procedures for artificial pollution tests applicable to polymeric insulators for overhead lines including traction lines, station post and hollow insulators of equipment. Available test experience with polymeric station post and hollow insulators, especially for DC applications, is limited.
The proposed tests are not applicable to ceramic and glass insulators without polymeric housing, to greased insulators or to special types of insulators (e.g., insulators with semiconducting glaze).
Differently to ceramic and glass insulators without polymeric housing:
- The pollution performance of insulators with polymeric housing varies with the hydrophobicity condition of the surface. The specific conditions simulated by standardized tests might not represent the actual dynamic field conditions.
- The determination of the flashover and/or withstand voltage under pollution conditions is not enough for dimensioning. Additional constraints related to possible ageing are also to be considered.
- If the Hydrophobicity Transfer Material (HTM) test according to IEC TR 62039 confirms that an insulator is non-HTM, it can be tested according to IEC 60507 or IEC TS 61245.

IEC TS 63493-1:2025 specifies the main parameters to facilitate interchangeability or at least to define some frame conditions of MV bushings:
- with Um from 12 kV up to and including 52 kV;
- Ir from 630 A up to and including 3 150 A.
This document deals with non-capacitance graded bushings for Power Transformers, according to the IEC 60076 series (usually for transformer with conservator).
In this document only liquid to air bushings are considered. Bushings of liquid-to-liquid and air-to-air type and bushings for transformers with air-cushion in tank are not considered.
MV is considered up to 52 kV; this value is used to cover specific insulation levels or for high pollution levels, even if the field of application is very restricted.
Both solutions with external insulation in porcelain and polymeric can be used and need to enable interchangeability (in terms of mechanical and electrical performance).

IEC TS 60815-3:2025, which is a technical specification, is applicable for the selection of polymeric insulators for AC systems, and the determination of their relevant dimensions, to be used in high voltage systems with respect to pollution. The specification applies to insulators for outdoor installation only.
This document gives specific guidelines and principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environment.
The contents of this document are based on CIGRE TB 158 and CIGRE TB 361, which form a useful complement to this document for those wishing to study in greater depth the performance of insulators under pollution.
This document does not deal with the effects of snow or ice on polluted insulators. Although this subject is dealt with by CIGRE TB 158, current knowledge is very limited and practice is too diverse.
The objective of this document is to give the user means to
- determine the reference unified specific creepage distance (RUSCD) from site pollution severity (SPS) value or class,
- choose appropriate profiles,
- apply correction factors for altitude, insulator shape, size and position, etc. to the RUSCD.
This second edition of IEC TS 60815-3, together with IEC TS 60815-1, cancels and replaces the first edition of IEC TS 60815-3:2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Terms and definitions are modified or introduced in this document;
b) From RUSCD of reference insulator to USCD of candidate insulator, the correction factors are introduced and revised, such as altitude correction, diameter correction, shed profile correction and - parallel insulator number correction;
d) The general guidance on materials is revised. The concept of hydrophobicity transfer and hydrophobicity transfer material (HTM) are introduced, recognising that a reduced creepage distance may be used for HTM insulators.

IEC TS 60815-2:2025, which is a technical specification, is applicable for the selection of ceramic and glass insulators for AC systems, and the determination of their relevant dimensions, to be used in high-voltage systems with respect to pollution. This document applies to insulators for outdoor installation only.
This document gives specific guidelines and principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments.
The basis for the structure and approach of this document is fully explained in IEC TS 60815­-1.
The objective of this document is to give the user means to:
- determine the reference unified specific creepage distance (RUSCD) from site pollution severity (SPS) value or class;
- evaluate the suitability of different insulator profiles;
- determine the necessary USCD by applying corrections for insulator shape, size, position, etc. to the RUSCD;
- if required, determine the appropriate test methods and parameters to verify the performance of the selected insulators.
This second edition of IEC TS 60815-2, together with IEC TS 60815-1, cancels and replaces the first edition of IEC TS 60815-2 published in 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Some terms and definitions are modified or introduced in this document, such as USCD, nominal creepage distance, RUSCD, creepage factor, insulator trunk, etc.;
b) From RUSCD of reference insulator to USCD of candidate insulator, the correction factors are introduced and revised, such as altitude correction, diameter correction, shed profile correction and parallel insulator number correction;
c) Profile suitability on ceramic and glass insulators was simplified.

IEC TS 60815-1:2025 is applicable to the selection of insulators, and the determination of their relevant dimensions, to be used in outdoor high-voltage systems with respect to pollution. For the purposes of this technical specification series, the insulators are divided into the following broad categories, each dealt with in a specific part as follows:
- IEC TS 60815-2 – Ceramic and glass insulators for AC systems;
- IEC TS 60815-3 – Polymer insulators for AC systems;
- IEC TS 60815-4 – Insulators for DC systems.
This document provides general definitions, gives methods for the evaluation of site pollution severity (SPS) and outlines the principles to arrive at an informed judgement on the probable behaviour of a given insulator in certain pollution environments. The general principles described are applicable to both AC and DC systems. However, the applicability part mainly refers to AC. More information about DC can be found in IEC TS 60815-4.
This document is applicable to all types of external insulation, including insulation forming part of other apparatus. The term "insulator" is used hereafter to refer to any type of insulator.
The objective of this technical specification series is to:
- understand and identify parameters of the system, application, equipment and site influencing the pollution behaviour of insulators,
- understand and choose the appropriate approach to the design and selection of the insulator solution, based on available data, time and resources.
- characterise the type of pollution at a site and determine the site pollution severity (SPS) value and the SPS class,
- determine the reference unified specific creepage distance (RUSCD) of "reference" insulator based on the SPS class,
- select candidate insulators and determine corrections to apply to RUSCD to arrive at the USCD of the "candidate" insulators by taking into account their specific properties (notably their shed profiles), conditions of the site, the application and the type of system,
- evaluate the relative advantages and disadvantages of the possible solutions, using HTM or non-HTM insulators,
- assess the need and merits of "hybrid" solutions or mitigative measures.
The IEC 60815 series does not deal with the effects of ice and snow on polluted insulators.
CIGRE documents form a useful complement to this technical specification for those wishing to study in greater depth the performance of insulators under pollution.
This second edition cancels and replaces the first edition of IEC TS 60815‑1 published in 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) In the Scope, it is clarified that this specification is applicable to AC and DC conditions while it mainly refers to AC conditions. Detailed application indications refer to AC only. The RUSCD is determined based on the SPS class of reference insulators, and this document does not deal with the effects of ice and snow on polluted insulators;
b) Some terms and definitions are modified or introduced in this document, such as RUSCD, creepage factor, average diameter, SPS value and SPS class, hydrophobicity transfer and HTM, etc.;
c) Clause 5 is re-organized and revised regarding input parameters for the selection and dimensioning of insulators, including system requirements and environmental conditions;
d) Clause 6 "Determination of site pollution severity (SPS) class" is re-organized and re-written. A distinction was made between SPS value and SPS class. The measurement of pollution that is made on the de-energized reference insulator is valid for AC only;
e) A new pollution class, extremely heavy class f, is added. It is applicable only to the special situations of extremely heavy pollution when the RUSCD of class e cannot meet the requirements. The RUSCD value for class f is not specified;
f) The parameters of reference insulators were defined;
g) The pro

IEC 62217:2025 is applicable to polymeric insulators for AC systems with a nominal voltage greater than 1 000 V (frequency less than 100 Hz) and DC systems with a nominal voltage greater than 1 500 V whose insulating body consists of one or various organic materials. Polymeric insulators covered by this document are intended for use both on HV overhead lines and in substations, in both indoor and outdoor applications. They include composite insulators with solid and hollow core and resin insulators. Hybrid insulators with ceramic core and polymeric housing are also included, while coated insulators (e.g. with RTV silicone rubber coatings) are not included in this standard. Electrical tests described in this document are done under AC voltage and are in general applicable to insulators to be used in DC systems too. Tests under DC voltage are intended to reflect up-to-date knowledge and experience. Only polymeric housing materials of hybrid insulators are specified in this document. Tests for core materials and the interfaces between housing and core of hybrid insulators are not included.
The object of this document 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 lifetime under normal operating and environmental conditions. This document includes design tests intended to reject materials or designs which are inadequate under normal operating and environmental conditions. This document defines test methods and acceptance criteria. The applicable tests are given in the relevant product standard. This third edition cancels and replaces the second edition published in 2012. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) The scope of the document is specified to comprise composite insulators with solid and hollow core and resin insulators used for both AC and DC systems in indoor and outdoor applications of HV overhead lines and substations; hybrid insulators (defined in IEC TS 62896) with ceramic core and polymeric housing are also included, while coated insulators (e.g. with Room Temperature Vulcanized (RTV) silicone rubber coatings) are not considered in this document;
b) Steep-front impulse voltage test is modified to avoid unwanted flashovers between the leads of the electrodes;
c) Differences between hydrophobicity transfer material (HTM) and non-HTM housing materials are specified and relevant test methods and acceptance criteria for polymeric insulators with HTM housing are introduced;
d) The previous water diffusion test on core materials with or without housing is split into two tests. One is on core materials without housing, the other is on core materials with housing. The acceptance criteria are modified;
e) Stress corrosion test for core materials is introduced;
f) Annex B summarizes the test application for evaluating the quality of interfaces and connections of end fittings, housing materials and core materials;
g) Annex E is introduced to emphasize the need for control of electric fields of polymeric insulators for AC. The control of electric fields of polymeric insulators for DC is still under consideration.

IEC/IEEE 65700-19-03:2025 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 liquid-filled converter transformers and smoothing reactors, as well as air-to-air DC bushings. It applies to both line commutated converter (LCC), as well as voltage source converter (VSC) technologies. This document does not apply to the following:
- cable terminations (potheads);
- bushings for instrument transformers;
- bushings for test power supplies;
- bushings applied with gaseous insulation (other than air at atmospheric pressure) external to the bushing;
- bushings for industrial application;
- bushings for traction application;
- bushings for distribution class transformers.
This second edition cancels and replaces the first edition published in 2014. This edition constitutes a technical revision and includes the following significant technical changes with respect to the previous edition:
- service experiences as well as established market requirements have been harmonized with existing IEC and IEEE standards, primarily IEC 60137, Insulated bushings for alternating voltages above 1 000 V, and IEEE Std C57.19.00™, IEEE Standard General Requirements and Test Procedures for Outdoor Power Apparatus Bushings;
- inclusion of voltage source converter (VSC) technologies.

IEC 61109:2025 applies to composite insulators for overhead lines consisting of a load-bearing cylindrical insulating solid core consisting of fibres - usually glass - in a resin-based matrix, a housing (surrounding the insulating core) made of polymeric material and metal end fittings permanently attached to the insulating core. Composite insulators covered by this document are intended for use as suspension/tension line insulators, but these insulators could occasionally be subjected to compression or bending, for example when used as interphase-spacers. Guidance on such loads is outlined in Annex C.
The object of this document is to:
- define the terms used,
- specify test methods,
- specify acceptance criteria.
This third edition cancels and replaces the second edition published in 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- extension of this document to apply both to AC and DC systems;
- modifications of Clause 3, Terms, definitions and abbreviations;
- removal of Clause 7, Hybrid insulators, from this document;
- modifications of tests procedures recently included in IEC 62217 (hydrophobicity transfer test, stress corrosion, water diffusion test on the core with housing);
- modifications on environmental conditions;
- modifications on classification of tests and include the relevance of the interfaces;
- clarification and modification of the parameters determining the need to repeat design and type tests;
- revision of Table 1;
- revision of electrical type tests;
- revision of re-testing procedure of sample test;
- addition of a new Annex D on electric field control for AC;
- addition of a new Annex E on typical sketch for composite insulators assembly;
- addition of a new Annex F on mechanical evaluation of the adhesion between core and housing;
- addition of a new Annex G on applicability of design- and type tests for DC applications.

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 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 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 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 60815-3:2008(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/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 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.