New impregnating materials with a thermal rating of 155 to 180 °C

New impregnating varnishes and UP-Resins are introduced with respect to application properties, dielectric and thermal behaviour. Thermal evaluation of these materials is discussed and the various procedures are compared. Results obtained lead to the conclusion that a rod type specimen should be preferred rather than a sheet type specimen if a better correspondence between thermal evaluation and experience from service conditions is desired.