scope:

This part of 60216 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 60216-1 and 60216-2. The calculation procedures are supplementary to those of 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 IEC 60216-3, clause 3.1). Guidance is given for preliminary assignment of a material to an insulation class, based upon the thermal ageing performance.