IEC 60216-8:2013

IEC 60216-8 ®
Edition 1.0 2013-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical insulating materials – Thermal endurance properties –
Part 8: Instructions for calculating thermal endurance characteristics using
simplified procedures
Matériaux isolants électriques – Propriétés d'endurance thermique –
Partie 8: Instructions pour le calcul des caractéristiques d'endurance thermique
en utilisant des procédures simplifiées

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IEC 60216-8 ®
Edition 1.0 2013-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electrical insulating materials – Thermal endurance properties –

Part 8: Instructions for calculating thermal endurance characteristics using

simplified procedures
Matériaux isolants électriques – Propriétés d'endurance thermique –

Partie 8: Instructions pour le calcul des caractéristiques d'endurance thermique

en utilisant des procédures simplifiées

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 17.220.99; 29.035.01 ISBN 978-2-83220-679-9

– 2 – 60216-8 © IEC:2013
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, symbols and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Symbols and abbreviations . 8
4 Thermal endurance test procedure . 9
4.1 General . 9
4.2 Number of test specimens . 9
4.3 Preparation of test specimens . 10
4.4 Preparation of ageing processes . 11
5 Simplified numerical and graphical evaluation procedures . 12
5.1 Outline description of procedures . 12
5.2 Simplified calculation procedures . 13
5.2.1 Validity of simplified calculations . 13
5.2.2 Times to end-point . 13
5.2.3 Calculation of the regression line . 14
5.2.4 Calculation of deviation from linearity . 15
5.2.5 Temperature index and halving interval . 15
5.3 Data rescue . 16
5.4 Determination of RTI . 16
5.5 Test report . 18
Bibliography . 19

Figure 1 – Determination of the time to reach the end-point at each temperature –
Property variation (according to IEC 60216-1) . 14
Figure 2 – Thermal endurance graph – Temperature index – Halving interval . 16
Figure 3 – Thermal endurance graph – Relative temperature index . 17

Table 1 – Suggested exposure temperatures and times for TI corresponding to
20 000 h . 12

60216-8 © IEC:2013 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATING MATERIALS –
THERMAL ENDURANCE PROPERTIES –

Part 8: Instructions for calculating thermal endurance
characteristics using simplified procedures

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60216-8 has been prepared by IEC technical committee 112:
Evaluation and qualification of electrical insulating materials and systems.
The text of this standard is based on the following documents:
FDIS Report on voting
112/236/FDIS 112/244/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – 60216-8 © IEC:2013
A list of all parts in the IEC 60216 series, published under the general title Electrical insulating
materials – Thermal endurance properties, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60216-8 © IEC:2013 – 5 –
INTRODUCTION
The designation 'thermal endurance' is used here to refer to the test of thermal stress in air,
excluding any other influence or stress applied to the test specimens. Thermal endurance
properties evaluated in different environments and/or with different stresses applied to the
test specimens require different test procedures.
In this part of IEC 60216, the study of the thermal ageing of materials is based solely on the
change in certain properties resulting from a period of exposure to elevated temperature. The
properties studied are always measured after the temperature has returned to ambient.
Properties of materials change at various rates on the
...