designation of an insulating material or system by a number that is equal to the numerical value of the Celsius maximum temperature
expressed in degrees Celsius for which the material or system is appropriate in normal use
NOTE 1 – It may be necessary to assign different thermal classes to the same material or system for different service conditions.
NOTE 2 – The description of an electrotechnical product as being of a particular thermal class does not mean, and must not be taken to imply that each insulating material used in its construction is of the same thermal capability.
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