Evaluation of alternate mineral oils for use in transformers and other electrical apparatus

Abstract

Since World War I, electrical insulating oils for transformers and allied electrical equipment have been refined from naphthenic petroleum crude oil stocks. The resulting oils have had acceptable dielectric, mechanical and heat transfer properties and little or no wax formation occurs at temperatures down to −40°C. Usable naphthenic crude oils appear to be coming into short supply and there is a real possibility of a short fall in supply of the traditional oils in the 1980's. This report describes the results of a program directed toward evaluation of potential replacement liquids, particularly other mineral oils.