The Development and Application of Synthetic Liquid Dielectrics

Abstract

This paper describes the development and application of synthetic liquid dielectrics consisting of chlorinated aromatic molecules which contain at least a chemical equivalent of chlorine and hydrogen. With such an equivalent not only are the chlorinated products themselves non‐inflammable in the usual sense, but in addition show no tendency toward autogenous ignition and when decomposed by an electric arc evolve only gases which are non‐inflammable and non‐explosive. New types of chlorinated aromatic hydrocarbons are indicated. These products, normally solid when pure, may be obtained in the liquid state. Properly blended, synthetic dielectrics having pour points lower than −20° C. are possible. The introduction of these materials in electrical design, replacing mineral oil, not only removes the potential fire and explosion risk, but also offers a liquid dielectric with pronounced chemical stability, essentially non‐oxidizing and non‐sludging and with a dielectric strength even higher than that normally associated with the best of mineral insulating oils.