Silicone retrofill of askarel transformers

The purpose of this paper is to describe the actual method used in the field retrofilling of askarel filled transformers with silicone liquid and to enumerate the related issues involved, including liability, safety, and environmental problems. The discussion will cover such items as proper draining, flushing, regasketing and filling. The necessary pre-retrofill information such as that furnished by the owner and the information needed from the transformer manufacture will also be presented. The final section of the paper will consider the testing of the transformer both before and after retrofilling to determine if the unit is dielectricly acceptable.