Development of methods to retrofill transformers with silicone transformer liquid

Sumnary-Because of new environmental and safety requirements for electrical equipment, silicone dielectric liquids are presently being used and evaluated as a transformer coolant. In the transformer maintenance and repair industry there is an interest and need to develop procedures to remove the existing liquid in & transformer, clean the transformer and refill it with silicone transformer liquid. This paper describes retrofilling experiences and related experimentation carried out over the past 5(+) years. Pressure, solubility, processing, water, and other topics including specific case histories are covered. The data and information collected on retrofill of transformers with silicone transformer liquid confirm that such a practice can technically be accomplished.