As is stated in AIEE No. 1, accelerated life tests are recommended to determine the probable life expectancy of electrical insulating materials and of complete insulation systems under different conditions of service. Recommended procedures for conducting life tests at various temperatures to accelerate insulation degradation are outlined in AIEE 1D and lE. AIEE publications Nos. 57, 65, 510 and 511 are examples of test procedures developed for this purpose. After life data from such tests have been obtained at different temperatures, the problem is to evaluate the resultant data so that the life expectancy of insulation can be estimated. For this purpose, life expectancy is considered as a function of temperature. The most probable form of this relationship, and its reliability, are determined by the statistical procedures outlined herein.

As is stated in AIEE No. 1, accelerated life tests are recommended to determine the probable life expectancy of electrical insulating materials and of complete insulation systems under different conditions of service. Recommended procedures for conducting life tests at various temperatures to accelerate insulation degradation are outlined in AIEE ID and IE. AIEE publications Nos. 57, 65, 510 and 511 are examples oftest procedures developed for this purpose. After life data from such tests have been obtained at different temperatures, the problem is to evaluate the resultant data so that the life expectancy of insulation can be estimated. For this purpose, life expectancy is considered as a function of temperature. The most probable form of this relationship, and its reliability, are determined by the statistical procedures outlined herein.