IEEE 99:2019

Revision Standard - Active.
A general form for the preparation of test procedures is provided in this standard. Points to be considered by technical committees in the preparation of specific instructions for the thermal evaluation of insulation systems for electric equipment are suggested. The test procedures involve accelerated thermal aging of insulation systems and specify tests that the committees deem pertinent based on conditions of use. The objective of the procedures is to provide for the functional evaluation, by test, of insulation systems for electric equipment.

This recommended practice provides criteria for the preparation of test procedures for accelerated thermal aging of insulation systems for electrical equipment and for the specification of tests based on conditions of use. The objective of these test procedures is to provide for the functional evaluation, by test, of insulation systems for electrical equipment.
This recommended practice provides a general format for the preparation of test procedures and suggest the points to be considered by technical committees in the preparation of specific instructions for the thermal evaluation of insulation systems for electrical equipment. The thermal evaluation of an insulation system involves the following thermal factors of influence:
- Exposure temperature
- Ambient temperature
- Temperature gradient
- Rate of temperature change