TC 112 - Evaluation and qualification of electrical insulating materials and systems

IEC 60216-1:2025 specifies the general ageing conditions and procedures to be used for deriving thermal endurance characteristics and gives guidance in using the detailed instructions and guidelines in the other parts of IEC 60216. Although originally developed for use with electrical insulating materials and simple combinations of such materials, the procedures are considered to be of more general applicability and are widely used in the assessment of materials not intended for use as electrical insulation. In the application of this document, it is assumed that a practically linear relationship exists between the logarithm of the time required to cause the predetermined property change and the reciprocal of the corresponding absolute temperature (Arrhenius relationship). For the valid application of this document, no transition, in particular no first-order transition, is expected to occur in the temperature range under study.
This edition includes the following significant technical changes with respect to the previous edition:
a) the definition for temperature index (TI) has been updated;
b) requirements for selection of related materials used, e.g. in different colours (5.1.2), have been added;
c) test procedure for thickness sensitivity (5.5 et 6.6) has been added;
d) Annex C "Concepts in earlier editions" has been deleted.

IEC TS 61857-42:2025 provides a procedure to evaluate the lifetime of an electrical insulation system (EIS) in a drivetrain unit within road transportation (automotive) applications. Typical applications include motors and generators in hybrid and full electric passenger vehicles, light-duty and heavy-duty commercial vehicles, as well as buses.
In general, the IEC 61857 series is applicable to EIS used in electrotechnical products with an input voltage of up to 1 000 V where the predominant ageing factor is thermal. In the context of this document the limit of 1 000 V is understood to be the application-specific battery DC voltage.
The EIS evaluated by this procedure will operate free from partial discharges over its whole lifetime.
Evaluation of EIS in the following applications is outside the scope:
- motors and generators within the scope of IEC TC 2, Rotating machinery;
- rail traction machines in the scope of IEC TC 9, Electrical equipment and systems for railways;
- motors and generators for road vehicles that are not intended for the traction of them.

IEC 60112:2025 specifies the method of test for the determination of the proof and comparative tracking indices of solid insulating materials on pieces taken from parts of equipment and on plaques of material using alternating voltage. This document provides a procedure for the determination of erosion when required. The proof tracking index is used as an acceptance criterion as well as a means for the quality control of materials and fabricated parts. The comparative tracking index is mainly used for the basic characterization and comparison of the properties of materials. This test method evaluates the composition of the material as well as the surface of the material being evaluated. Both the composition and surface condition directly influence the results of the evaluation and are considered when using the results in material selection process. The described test method is designed for a test voltage up to 600 V AC, because higher test voltages and DC voltage will lead to a reduced test severity. Test results are not directly suitable for the evaluation of safe creepage distances when designing electrical apparatus. The results of this method have been used for insulation coordination of equipment. It is important that use of these results also considers the overvoltage levels, creepage distances, and establishes the pollution degree to which the product insulation system will be expected to be subjected. This is in compliance with IEC 60664-1. This basic safety publication focusing on a safety test method is primarily intended for use by technical committees in the preparation of safety publications in accordance with the principles laid down in IEC Guide 104 and lSO/lEC Guide 51. One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. This sixth edition cancels and replaces the fifth edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
- In 7.3, the term "resistivity" has been replaced by "conductivity".
It has the status of a basic safety publication in accordance with IEC Guide 104.

IEC TR 61857-2:2025 gives guidelines to identify the appropriate test method for the evaluation of a proposed electrical insulation system (EIS). Some of the standards evaluate the EIS using one stress factor which is thermal. Other standards evaluate the thermal stress factor with adjustments to the conditioning applied prior to the diagnostic testing to simulate applications in air. A third group of these standards when the application is other than in air. This technical report is applicable to existing or proposed EIS used in electrotechnical products across a wide range of operating voltages of IEC Standards. The report takes care to identify the appropriate standard based on construction and intended operating application.
For all performance and safety requirements related to an application, refer to the technical committee requirements for the application.
This edition includes the following significant technical changes with respect to the previous edition.
a) The Introduction is expanded to convey that both TC 112 and TC 2 have established EIS test standards.
b) Clause 4 introduces the fact that there are four stress factors, not only thermal. This essential concept carries over into part of Clause 5.
c) The large number of established standards are organized into common concept groups in Tables 1 to 5:
1) Table 1 covers an overview of EIS evaluations for background and structure.
2) Table 2 covers evaluation of test objects prior to the start of long-term thermal ageing using screening tests.
3) Table 3 covers test standards for the evaluation of thermal stresses in air and has an increased number of standards.
4) Table 4 covers standards for special environmental applications other than in air
5) Table 5 covers standards for the modification of an established EIS.

IEC TR 60216-7-2:2024 is intended to validate the procedures of IEC TS 60216-­7-­1 in providing a similar temperature index to conventional methods used in other parts of the IEC 60216 series. The round robin test results do not provide statistical analysis for precision. The round robin test focuses on preliminary studies to understand the evaluation and calculation procedures, influence on apparatus, and data variance among laboratories before determination of precision. This second edition cancels and replaces the first edition published in 2016. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Annex A (informative) has been added to provide a round robin test with a different polymer type - polybuthylene terephthalate (PBY) - as an additional use case of the method in accordance with IEC TS 60216-7-1;
b) Tables 3 to 11 have been corrected by adding units, and texts have been refined for more technical clarifications of the procedures and observations.

IEC 62631-3-12:2024 specifies a method of test for the determination of volume resistance and volume resistivity of electrical insulation materials by applying a DC voltage. It covers casting resins described in IEC 60455-3-1, IEC 60455-3-2, IEC 60455-3-3, IEC 60455-3-4, IEC 60455-3-8 and similar products.
For other specific types of materials, other standards or the general method described in IEC 62631-3-1 can be more suitable.

IEC 63177:2024 specifies the test method for the compatibility of construction materials with electrical insulating liquids for use in electrical equipment, such as liquid-immersed transformers and tap-changers, liquid-impregnated capacitors, and liquid-cooled rotating machines used in electrical vehicles and oil pumps. This document is applicable to mineral insulating liquids, natural esters, silicone insulating liquids, synthetic organic esters, modified esters, capacitor fluids based on synthetic aromatic hydrocarbons and e-transmission fluids used in electrical vehicles and oil pumps. The compatibility tests are not sufficient for a full qualification of construction materials for a given application without additional tests requested by the appropriate IEC Technical Committee or equipment manufacturers.

IEC 62631-2-3:2024 specifies the measuring technology and the test method for the relative permittivity and dielectric dissipation factor of thin single layer insulating polymer film without any additional metallization on the sample surface. The adaptive thickness range is approximately 10 μm to 100 μm. The proposed frequency is the power frequency (50 Hz or 60 Hz), and it is also suitable in the technical frequency range from 1 Hz to 1 MHz.
The content of the corrigendum 1 (2025-04) has been included in this copy.

IEC 62836:2024 provides an efficient and reliable procedure to test the internal electric field in the insulating materials used for high-voltage applications, by using the pressure wave propagation (PWP) method. It is suitable for a planar and coaxial geometry sample with homogeneous insulating materials of thickness larger or equal to 0,5 mm and an electric field higher than 1 kV/mm, but it is also dependent on the thickness of the sample and the pressure wave generator.
This first edition cancels and replaces IEC TS 62836 published in 2020.
This edition includes the following significant technical changes with respect to IEC TS 62836:
a) addition of Clause 12 for the measurement of space charge distribution in a planar sample;
b) addition of Clause 13 for coaxial geometry samples;
c) addition of Annex D with measurement examples for coaxial geometry samples;
d) addition of a Bibliography;
e) measurement examples for a planar sample have been moved from Clause 12 in IEC TS 62836 to Annex C.

IEC TS 61934:2024 is applicable to the off-line electrical measurement of partial discharges (PDs) that occur in electrical insulation systems (EISs) when stressed by repetitive voltage impulses generated from power electronics devices.
Typical applications are EISs belonging to apparatus driven by power electronics, such as motors, inductive reactors, wind turbine generators and the power electronics modules themselves.
NOTE Use of this document with specific products can require the application of additional procedures.
Excluded from the scope of this document are:
- methods based on optical or ultrasonic PD detection,
- fields of application for PD measurements when stressed by non-repetitive impulse voltages such as lightning impulse or switching impulses from switchgear.
This edition includes the following significant technical changes with respect to the previous edition:
a) background information on the progress being made in the field of power electronics including the introduction of wide band gap semiconductor devices has been added to the Introduction;
b) voltage impulse generators; the parameter values of the voltage impulse waveform have been modified to reflect application of wide band gap semiconductor devices.
c) PD detection methods; charge-based measurements are not described in this third edition nor are source-controlled gating techniques to suppress external noise.
d) Since the previous edition in 2011, there have been significant technical advances in this field as evidenced by several hundreds of publications. Consequently, the Bibliography in the 2011 edition has been deleted in this third edition.

IEC 62631-3-2:2023 describes methods of test for the determination of surface resistance and surface resistivity of electrical insulation materials by applying DC voltage. This edition includes the following significant technical changes with respect to the previous edition:
a) descriptions of the electrode arrangements have been clarified;
b) new descriptions of the conductive means have been added;
c) a new informative Annex B summarizing the results of the comparative verification study on surface resistivities using different electrode arrangements has been added.

IEC 62631-3-1:2023 specifies a method of test for the determination of volume resistance and volume resistivity of electrical insulating materials by applying a DC voltage. This edition includes the following significant technical changes with respect to the previous edition:
- following the withdrawal of IEC 60093 and its partial replacement with the first edition of IEC 62631-3-1, the missing editorial and technical texts have been added and incorporated into this second edition of IEC 62631-3-1;
- the alignment of normative texts and informative notes have been addressed as well as the normative references and bibliography.

IEC 60216-6:2022 specifies the experimental and calculation procedures for deriving the thermal endurance characteristics, temperature index (TI) and relative temperature index (RTI) of an electrical insulating material (EIM) using the “fixed time frame method (FTFM)”. In this protocol, the ageing takes place for a small number of fixed times, using the appro­priate number of ageing temperatures throughout each time, the properties of the specimens being measured at the end of the relevant time interval. This differs from the procedure of IEC 60216-1, where ageing is conducted at a small number of fixed temperatures, property measurement taking place after ageing times dependent on the progress of ageing. The diagnostic tests employed in the fixed time frame method are restricted to destructive tests. The method has not yet been applied to non-destructive or proof test procedures. This edition includes the following significant technical changes with respect to the previous edition:
- clarification of definition of index properties vs. endurance properties;
- complete rework of Annex G and the corresponding program.

IEC 60216-5:2022 specifies the experimental and calculation procedures to be used for deriving the relative temperature index of a material from experimental data obtained in accordance with the instructions of IEC 60216-1 and IEC 60216-2. The calculation procedures are supplementary to those of IEC 60216-3. Guidance is also given for assessment of thermal ageing after a single fixed time and temperature, without extrapolation. This edition includes the following significant technical changes with respect to the previous edition:
Annex C “Computer program” has been completely reworked;
in 3.1, the terms “ATE” and “RTE” were replaced by “ATI” and “RTI” to emphasize their reference to an electrical insulating material (EIM).
This standard is to be read in conjunction with IEC 60216-1:2013, IEC 60216-2:2005 and IEC 60216-3:2021.

IEC 60544-5:2022 covers ageing assessment methods which can be applied to components based on polymeric materials (e.g. cable insulation and jackets, elastomeric seals, polymeric coatings, gaiters) which are used in environments where they are exposed to radiation. The object of this document is aimed at providing methods for the assessment of ageing in service. The approaches discussed in Clause 5 through Clause 9 cover ageing assessment programmes based on condition monitoring (CM), the use of sample deposits in severe environments and sampling of real-time aged components. This edition includes the following significant technical changes with respect to the previous edition:
- added recent references in 7.4 showing that some electrical condition monitoring methods show promising correlations with ageing;
- updated recommendations for implementation of a sample deposit in 9.2, installation of a sample deposit in 9.3 and testing of samples from the deposit in 9.4;
- updated list of references.

IEC 62631-2-2:2022 specifies test methods for the determination of permittivity and dissipation factor properties of solid insulating materials in a high frequency range from 1 MHz to 300 MHz.

IEC 60587:2022 describes two test methods for the evaluation of electrical insulating materials for use under severe ambient conditions at power frequencies (45 Hz to 65 Hz) by the evaluation of the resistance to tracking and erosion, using a liquid contaminant and inclined plane specimens. The two methods are:
- Method 1: test at constant voltage,
- Method 2: test at stepwise increased voltage.
Method 1 is the most widely used method as there is less need for continual inspection.
The test conditions are designed to accelerate the production of the effects, but do not reproduce all the conditions encountered in service.
This edition includes the following significant technical changes with respect to the previous edition:
a) an improved description of the experimental methods has been implemented;
b) an improved description of the preparation of the test specimens has been implemented;
c) a more detailed description of the electrode material and of the electrode quality has been added;
d) evaluation criterion B (track length) has been removed for testing according to test method 2 (stepwise tracking voltage) as it is not applicable.

IEC TR 62039:2021(E) presents the important material properties of polymeric materials used in outdoor insulation and, where applicable, lists standardized test methods including minimum requirements. If no standardized tests are available, the test methods reported in literature are summarized.
This document is valid for insulating materials having polymeric insulation, which are used in outdoor high voltage electrical applications with a system voltage greater than 1 000 V AC and 1 500 V DC (several tests are only defined for alternating current, which are not applicable for direct current). Such applications are relevant where the housing is an integral part of the device, for example in surge arresters and cable terminations. The scope of this document is limited to the insulation materials only and is not generally intended for coating materials (coating materials are, for example, thin layers applied on toughened glass and ceramic). Some tests mentioned in this document are applicable for coating and are under consideration by CIGRE. The performance of insulators in service depends on several factors such as the type of material, the design and environmental conditions. Consequently, the choice of materials that fulfil the requirements listed in Table 1 is a necessary condition but does not guarantee satisfactory performance when used in outdoor insulation.

IEC 60216-3:2021 specifies the calculation procedures used for deriving thermal endurance characteristics from experimental data obtained in accordance with the instructions of IEC 60216-1 and IEC 60216-2, using fixed ageing temperatures and variable ageing times. The experimental data can be obtained using non-destructive, destructive or proof tests. Data obtained from non-destructive or proof tests can be incomplete, in that it is possible that measurement of times taken to reach the end-point will have been terminated at some point after the median time but before all specimens have reached end-point. The procedures are illustrated by worked examples, and suitable computer programs are recommended to facilitate the calculations.
This edition includes the following significant technical changes with respect to the previous edition:
- a new computer program has been included;
- Annex E " has been completely reworked.

IEC TR 61858-3:2020(E) provides information on the identification of electrical insulating materials and auxiliary components for the assessment of modifications to an established insulation system and gives guidance on the selection of feasible test procedures.

IEC 60112:2020 specifies the method of test for the determination of the proof and comparative tracking indices of solid insulating materials on pieces taken from parts of equipment and on plaques of material using alternating voltage. This document provides a procedure for the determination of erosion when required.
This test method evaluates the composition of the material as well as the surface of the material being evaluated. Both the composition and surface condition directly influence the results of the evaluation and are considered when using the results in material selection process.
Test results are not directly suitable for the evaluation of safe creepage distances when designing electrical apparatus.
This basic safety publication focusing on a safety test method is primarily intended for use by technical committees in the preparation of safety publications in accordance with the principles laid down in IEC Guide 104 and lSO/lEC Guide 51.
This edition includes the following significant technical changes with respect to the previous edition:
Introduction of a new contaminant, solution C with a surfactant aligned with the test method of IEC 60587. The definition of the solution B was transferred to Annex B for backward reference.
Introduction of a screening test, considering the fact that some materials can withstand high test voltages, but fail at lower test voltages.
It has the status of a basic safety publication in accordance with IEC Guide 104.

IEC 61857-32:2019 series is focused on applications where other possible factors need to be incorporated to evaluate any influence on the performance of the electrical insulation system (EIS). Multi-factor evaluation is the most complex type of project to design and conduct. Clear guidelines are needed to give the user of this document a uniform approach and a method to analyse the test results.
This document is for applications where the stresses are some combination of other factors of influence identified in IEC 60505. The multi-factor stresses are applied during the diagnostic portion of each test cycle.
A few examples of other factors of influence or multi-factor stresses are:
– high vibration;
– submersion in oils, water, or solutions;
– voltage higher than the test voltage of the reference EIS;
– decreased cold shock temperature.

IEC TR 61244-4:2019(E) provides general guidance for the evaluation/verification of electrical insulation materials (EIM) and electrical insulation systems (EIS) intended to be used in types of equipment exposed to ionizing radiation. Beside sensors, actuators/motors as well as plugs and terminals, cables are a well-known typical application of those EIM and EIS. Their type spectrum covers low voltage power cables, control cables and instrumentation cables. Because of their comparable simple design, cables are the ideal type of equipment to study EIM and EIS degradation processes. But the results of these studies can be easily transferred to the enumerated types of equipment.
Nonetheless, this document provides a state-of-the art report on qualification/verification procedures used to simulate simultaneous effects of temperature and radiation at varying intensities rather than give detailed test programmes valid for specific test methods.
NOTE 1 Use of this document with specific products can require specification of additional product related procedures.
NOTE 2 Some of the procedures described in this document are emerging technologies. Therefore, specified prerequisites, former experiences as well as boundary conditions can be additionally taken into account.

IEC 62631-3-4:2019 covers procedures for the determination of insulation resistance and volume resistivity of insulating materials by applying DC-voltage and temperatures up to 800 °C. The typical application materials include high temperature mica plate and alumina ceramics.
This edition of IEC 62631-3-4 cancels and replaces IEC 60345 “Method of test for electrical resistance and resistivity of insulating materials at elevated temperatures”, published in 1971. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to IEC 60345:  
The revised standard becomes part of the series IEC 62631-3-x. Title of the standard is changed and adapted to the series as Part 3-4.
Clauses 2 "Normative references", 3 "Terms and definitions", and 4 "Significance" are added.
Subclauses 5.2 "Power supply, Voltage", 5.3.1.2 "Number of test specimens" and 5.3.1.3 "Conditioning and pre-treatment of test specimens" are added.
In 5.3.5 "Special precautions during measurements", errors analysis in the measurement of current are modified, and aligned with IEC 62631-3-1.
In 6.2 "Increasing the temperature by steps (method B)", the method for more than one specimen is removed.
The standard atmospheric conditions for testing and conditioning, especially the temperature, are replaced according to IEC 60212.
The circuit diagram of test apparatus is modified, and the structure diagram and pictures of test apparatus are added in Annex A.
The orders of part clauses are adjusted.

IEC 62631-2-1:2018 describes test methods for the determination of permittivity and dissipation factor properties of solid insulating materials (AC methods from 0,1 Hz up to 10 MHz).
This first edition cancels and replaces the first edition IEC 60250, published in 1969. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a. technical frequencies confined to AC methods;
b. update on measurements on solid dielectric materials.

IEC 62631-3-11:2018 covers a method of test for the determination of volume resistance and volume resistivity of electrical insulation materials by applying DC voltage. It covers the materials described in IEC 60455-3-5, IEC 60464-3-1, IEC 60464-3-2 and similar products.

IEC TR 60493-3:2017(E) clarifies how a statistical analysis can be done with a small number of samples. This document will be useful when the accelerated test method is difficult to carry out, for example in cases where the dimensions of test specimens (including test devices) are very large in scale or the cost of test specimens is high. Testing is facilitated by enabling users to reduce the number of test specimens.

IEC 61857-31:2017 establishes an EIS evaluation for applications with a designed life of 5 000 h or less. This test method follows the procedures of IEC 60505 and is modified based on the range of designed life.

IEC TR 60216-7-2:2016(E), which is a Technical Report, is to validate the procedures of IEC TS 60216-7-1 in providing a similar temperature index to conventional methods used in other parts of the IEC 60216 series. These round robin test results do not provide statistical analysis for precisions. The round robin test focuses on preliminary studies to understand the evaluation and calculation procedures, influence on apparatus, and data variance among laboratories before determination of precisions.

IEC TS 62332-3:2016 is applicable to EIM and EIS containing solid and liquid components where the refrigerant, oil and thermal stresses are the dominant ageing factor, without restriction to voltage class.

IEC 62631-3-1:2016 covers a method of test for the determination of volume resistance and volume resistivity of electrical insulation materials by applying a DC voltage. This edition includes the following significant technical changes with respect to the second edition of IEC 60093:
a) IEC 60093 has been completely revised, both editorially and technically, and incorporated into the new IEC 62631 series;
b) test methods have been updated to current day state of the art;
c) volume and surface resistance and resistivity are now separated to appear in this part of IEC 62631 and in IEC 62631-3-2, respectively.

IEC 62631-3-2:2015 covers methods of test for the determination of surface resistance and surface resistivity of electrical insulation materials by applying DC voltage. This first edition cancels and replaces the second edition of IEC 60093, published in 1980, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the second edition of IEC 60093:
a) IEC 60093 has been completely revised, both editorially and technically, and incorporated into the new IEC 62631 series;
b) test methods have been updated to current day state of the art;
c) volume and surface resistance and resistivity are now separated into IEC 62631-3-1 and IEC 62631-3-2, respectively.

IEC 62631-3-3:2015 covers methods of test for the determination of the insulation resistance of electrical insulating materials or insulating systems by applying DC voltage. This first edition cancels and replaces the first edition of IEC 60167, published in 1964, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the first edition of IEC 60167:
a) IEC 60167 has been completely revised, both editorially and technically, and incorporated into the new IEC 62631 series;
b) test methods have been updated to current day state of the art.

IEC 61251:2015 describes many of the factors involved in voltage endurance tests on electrical insulating materials and systems. It describes the voltage endurance graph, lists test methods illustrating their limitations and gives guidance for evaluating the sinusoidal a.c. voltage endurance of insulating materials and systems from the results of the tests. This International Standard is applicable over the voltage frequency range 20 Hz to 1 000 Hz. The general principles can also be applicable to other voltage shapes, including impulse voltages. The terminology to be used in voltage endurance is defined and explained. This first edition of IEC 61251 cancels and replaces the second edition of IEC TS 61251, published in 2008. This edition constitutes a technical revision and includes the following significant technical changes with respect to the second edition of IEC TS 61251:
a) upgrade from Technical Specification to an International Standard;
b) clarification of issues raised since publication of IEC TS 61251.

IEC TR 61857-2:2015(E) gives guidelines to identify the appropriate test method to be used for the evaluation of a proposed Electrical Insulation System (EIS). Some of the standards are for evaluation and classification of the EIS, while other standards identify the appropriate method to evaluate single or multi-factor stresses of a proposed or of an established EIS. This Technical Report is applicable to existing or proposed EIS used in electrotechnical products across a wide range of operating voltages of IEC Standards. The report takes care to select the appropriate standard based on construction and intended operating conditions.

IEC TS 60216-7-1:2015(E) describes the procedure for the evaluation of the thermal endurance of electrical insulating materials, based on thermal analysis methods for the evaluation of the activation energy of the thermal degradation reaction and a conventional life test providing a life point in the thermal endurance graph. The purpose of the test procedure is to estimate the relative temperature index (RTE).

IEC TS 61244-1:2014, which is a technical specification, reviews experimental techniques to quantitatively monitor the effects when oxygen is present during ageing of polymers in various environments including temperature, radiation or ultraviolet. This edition includes the following significant technical changes with respect to the previous edition:
a) numerical simulation of DLO is much improved;
b) geometry of samples has been expanded from only the case of the infinite plane to the cylindrical and the spherical cases.

IEC TS 61244-2:2014, which is a technical specification, applies to procedures for predicting ageing of polymeric materials at low dose rates. The object is to present three methods which can be used to extrapolate data obtained from high dose rate experiments to the low dose rates typical of service conditions. The techniques described are methods which have been found to be useful for a range of elastomeric, thermoplastic and thermoset materials. This edition includes the following significant technical changes with respect to the previous edition:
a) examples and background information moved to annexes;
b) examples updated with more recent references.

IEC TS 62332-2:2014 is applicable to EIS containing solid and liquid components where the thermal stress is the dominant ageing factor, without restriction to voltage class. This part specifies a sealed tube test procedure for the thermal evaluation and qualification of electrical insulation systems (EIS). One aspect of this procedure is to also provide a method to assign thermal classifications to materials used in EIS where solid and liquid components are both used. This procedure describes a comparative ageing method whereby a reference system composed of kraft paper and mineral oil is compared to a candidate system of any combination of solid and insulating liquid. The test procedures in this part are specifically applicable to liquid immersed transformer insulation systems.

IEC 61858-1:2014 lists the required test procedures for qualification of modifications of an established electrical insulation system (EIS) with respect to its thermal classification. This standard is applicable to EIS used in wire-wound winding electrotechnical devices. The test procedures are comparative in that the performance of a candidate EIS is compared to that of a reference EIS, which has proven service experience in accordance with IEC 60505 or has been evaluated by one of the procedures given in the IEC 61857 series. This first edition of IEC 61858-1 cancels and replaces the third edition of IEC 61858, published in 2008. It constitutes a technical and editorial revision. This edition includes the following significant technical changes with respect to the previous edition: a) this part is specifically for wire-wound winding EIS; b) new figures and charts support the contents.

IEC 61858-2:2014 lists the required test procedures for qualification of modifications of an established electrical insulation system (EIS) with respect to its thermal classification. This standard is applicable to EIS used in form-wound electrotechnical devices. The test procedures are comparative in that the performance of a candidate EIS is compared to that of a reference EIS, which has proven service experience in accordance with IEC 60505 or has been evaluated by one of the procedures given in IEC 60085 and IEC 60034-18-31.

IEC 60243-3:2013 gives requirements additional to those in IEC 60243-1 for the determination of the electric strength of solid insulating materials under 1,2/50 µs impulse voltage stress. This third edition cancels and replaces the second edition, published in 2001, and constitutes an editorial revision.
This publication is to be read in conjunction with IEC 60243-1:2013.

L'IEC 60243-2:2013 donne les exigences complémentaires à celles de la CEI 60243-1 pour la détermination de la rigidité diélectrique des matériaux isolants solides sous tension continue. Cette troisième édition annule et remplace la deuxième édition parue en 2001 et constitue une révision éditoriale.
Cette publication doit être lue conjointement avec la CEI 60243-1:2013.

IEC 60544-1:2013 deals broadly with the aspects to be considered in evaluating the effects of ionizing radiation on all types of organic insulating materials. It also provides, for X-rays, gamma-rays, and electrons, a guide to dosimetry terminology, methods for dose measurements, testing carried out at irradiation facilities, evaluation and testing of material characteristics and properties, documenting the irradiation process. This edition includes the following significant technical changes with respect to the previous edition:
a) recent advances in simulation methods of radiation interaction with different matter enables the prediction of the energy-deposition profile in matter and design the irradiation procedure;
b) many new dosimetry systems have become available.

IEC 60243-1:2013 provides test methods for the determination of short-time electric strength of solid insulating materials at power frequencies between 48 Hz and 62 Hz. This standard does not cover the testing of liquids and gases, although these are specified and used as impregnates or surrounding media for the solid insulating materials being tested. NOTE: Methods for the determination of breakdown voltages along the surfaces of solid insulating materials are included.

IEC 60216-1:2013 specifies the general ageing conditions and procedures to be used for deriving thermal endurance characteristics and gives guidance in using the detailed instructions and guidelines in the other parts of the standard. Although originally developed for use with electrical insulating materials and simple combinations of such materials, the procedures are considered to be of more general applicability and are widely used in the assessment of materials not intended for use as electrical insulation. In the application of this standard, it is assumed that a practically linear relationship exists between the logarithm of the time required to cause the predetermined property change and the reciprocal of the corresponding absolute temperature (Arrhenius relationship). For the valid application of the standard, no transition, in particular no first-order transition should occur in the temperature range under study. This sixth edition cancels and replaces the fifth edition, published in 2001. It constitutes an editorial revision where the simplified method has been removed and now forms Part 8 of the IEC 60216 series: Instructions for calculating thermal endurance characteristics using simplified procedures.

IEC 60216-8:2013 specifies the general ageing conditions and simplified procedures to be used for deriving thermal endurance characteristics, which are shown by temperature index (TI) and/or relative temperature index (RTI) and the halving interval (HIC). The procedures specify the principles for evaluating the thermal endurance properties of materials exposed to elevated temperature for long periods. In the application of this standard, it is assumed that a practically linear relationship exists between the logarithm of the time required to cause the predetermined property change and the reciprocal of the corresponding absolute temperature (Arrhenius relationship). For the valid application of the standard, no transition, in particular no first-order transition should occur in the temperature range under study.