WG 1 - TC 112/WG 1

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 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 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 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 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 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 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.

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 60212:2010 gives the accepted conditions of exposure time, temperature, atmospheric humidity and liquid immersion for use in testing solid electrical insulating materials. The range is sufficiently wide to enable suitable conditions to be selected so that either of the primary objects, set out below as a) and b), of conditioning can be achieved. These objectives aim to obtain greater reproducibility of test results by:
a) partly counteracting the variations of the properties of the material due to the past history of the test specimens (often known as "normalizing", here called preconditioning), and
b) ensuring uniformity of conditions during the testing.
This standard is not intended to be applied for determining the influence of exposure to certain temperatures and humidity or immersions in liquids, on the properties of a material. Procedures pertaining to the effect of an environment on a material are given in various parts of IEC 60068. The significant technical changes with respect to the previous edition are as follows:
- the scope and normative references have been updated and terms and definitions completely reviewed;
- technical details in Table 2 have been aligned to today's usage.

IEC 60216-3:2006 specifies the calculation procedures to be 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 may be obtained using non-destructive, destructive or proof tests. Data obtained from non-destructive or proof tests may be incomplete, in that measurement of times taken to reach the endpoint may 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. The major technical changes with regard to the first edition concern an updating of Table C.2. In addition, the scope has been extended to cover a greater range of data characteristics, particularly with regard to incomplete data, as often obtained from proof test criteria. The greater flexibility of use should lead to more efficient employment of the time available for ageing purposes. Finally, the procedures specified in this part of IEC 60216 have been extensively tested and have been used to calculate results from a large body of experimental data obtained in accordance with other parts of the standard. Annex E "Computer program" has been completely reworked.
Please be aware that the computer program provided in this publication is not compatible with the 64-bit version of Windows 7.

Covers minimum requirements for ventilated and electrically heated single-chamber ovens, with or without forced gas circulation, for thermal endurance evaluation of electrical insulation. It covers ovens designed to operate over all or part of the temperature range from 20 °C above ambient to 500 °C. It gives acceptance tests and in-service monitoring tests for these ageing ovens. The main changes with regard to the previous edition is that this edition adapts IEC 60216-4-1 to the technical content and the editorial form of IEC 60216-4-2 and IEC 60216-4-3. In addition, errors and omissions in the third edition have been corrected.

Gives guidance for the choice of test criteria for the determination of thermal endurance characteristics. It includes a list of existing published procedures which is however not exhaustive. The main changes from the previous edition are as follows: - editorial, - Table 1 has been actualized essentially by Part 3 sheets of SC 15C publications.
The content of the corrigendum 1 (2024-09) has been included in this copy.

Specifies the experimental and calculation procedures for deriving the thermal endurance characteristics, temperature index (TI) and relative thermal endurance index (RTE) of a material 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. Both the TI and the RTE determined according to the FTFM protocol are derived from experimental data obtained in accordance with the instructions of IEC 60216-1 and IEC 60216-2, as modified in this standard. The calculation procedures and statistical tests are modified in relation to IEC 60216-3 and IEC 60216-5.

Specifies the experimental and calculation procedures to be used for deriving the relative thermal endurance 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. The experimental data may in principle be obtained using destructive, non-destructive or proof tests, although destructive tests have been much more extensively employed. Data obtained from non-destructive or proof tests may be "censored", in that measurement of times taken to reach the endpoint may have been terminated at some point after the median time but before all specimens have reached end-point (see 3.1 of IEC 60216-3). Guidance is given for preliminary assignment of a material to an insulation class, based upon the thermal ageing performance. The second edition differs from the first in that it no longer aims to provide general guidance on application of thermal endurance characteristics, but provides instructions for deriving a provisional estimate of the temperature up to which a material may give satisfactory performance in an application (by comparative thermal ageing with a material of known performance).

Specifies the calculation procedures to be used for deriving thermal endurance characteristics from experimental data obtained in accordance with the instructions of IEC 60216-1 and IEC 60216-2. The experimental data may be obtained using non-destructive, destructive or proof tests. Data obtained from non-destructive or proof tests may be incomplete, in that measurement of times taken to reach the endpoint may 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.

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. Simplified procedures are also given, with the conditions under which these procedures may be used. 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 predeter-mined 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.

Covers minimum performance requirements for ventilated and electrically heated precision ovens for thermal endurance evaluation of electrical insulating materials and other appropriate applications. It covers ovens designed to operate over all or part of the temperature range from 20 K above room temperature up to 300°C. Two possible methods of achieving the required performance are described: a) where the required performance is achieved by precise control of temperature in a simple single chamber oven, i.e., upgraded versions of ovens conforming to IEC 60216-4-1, and, otherwise b)where the required performance is achieved by utilizing a second chamber (iso-box), mounted within the chamber of a single-chamber oven, the purpose of which is to reduce the magnitude of any temperature changes to an acceptable level whilst maintaining the required levels of air changes and circulation.

Covers the minimum requirements for ventilated and heated multi-chamber ovens used for thermal endurance evaluation of electrical insulation and of any other appropriate thermal conditioning application where the use of single-chamber ovens is inappropriate. Covers ovens designated to operate over all or part of the temperature range from 20 K above ambient to 500°C. Gives acceptance tests and in-service monitoring tests for both unloaded and loaded multi-chamber ovens and conditions of use.

Gives guidance to technical committees wishing to develop lists of maximum allowable temperatures for polymeric compounds under normal and abnormal operating conditions, covering: a) the factors which influence the choice of an appropriate method of describing polymeric compounds b) the factors which influence the selection of data for inclusion in lists of maximum allowable temperatures for polymeric compounds under normal operating conditions c) lists for the maximum allowable temperatures for polymeric compounds under abnormal operating conditions The recommended layout for any lists is given.