Effect of Temperature and Thermal Aging on the Electrical Charactceristics of Film-Type Wire Insulation in Transformer Oil

This paper presents observations and data on various types of film insulations tested under various environmental conditions which show the effect of temperature and thermal aging on the dissipation factor and dielectric strength. A test procedure is suggested for film insulations intended for use in sealed oil-immersed apparatus, whereby the dielectric characteristics are obtained at an aging temperature and under aging conditions.