This Standard is applicable to the cases where the thermal factor is the dominant ageing factor.

NOTE 1 A thermal class of a certain electrical insulation system cannot be assigned to the electrical insulating material which is used therein solely because of its use in the electrical insulation system.

NOTE 2 The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows.

IEC 60085 : 2007 Electrical insulation – Thermal evaluation and designation (MOD)

The symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21-1.