Thermal degradation of electrical insulating materials and the thermokinetic background: experimental data

For pt.I see ibid., vol.25, 1029-1036, 1990. The purpose of this work is to verify the validity of the new degradation model and the transformation equations which have been developed on the basis of thermokinetic considerations. This verification is implemented by comparing the temperature index (TI) values obtained by the thermal life equations, and their converted forms as transformation equations, for a large amount of material data with TI results estimated by tests carried out according to IEC Standard 216. The TI values relate to insulating materials with constant endurance-line slope as well as to materials with both constant and variable endurance-line slope. These families of life lines are named either parallel or nonparallel life lines. The equations developed provide estimates of the TIs that are, in general, close to those obtained by thermal endurance tests conducted according to IEC 216 procedures