Vapor-cooled terminal-bushings for oil-type circuit-interrupters

Abstract

An improved vapor-cooled terminal-bushing is provided for increased current-carrying capacity, such as 6,000 amperes, for example, in an oil-type circuit-breaker, being provided with a "dry" body portion, utilizing resinous materials, such as epoxy-resin formulations, for example. Preferably, the body portion of resinous materials, such as epoxy resin, for example, is composite, or of a two-piece construction, having an inner first epoxy-resin formulation having improved dielectric strength, and an outer-disposed externally-located "petticoat"-type insulating second body portion, having weather-sheds, the second weather-shed annular body portion being preferably cast directly onto the inner high-dielectric-strength first epoxy-body portion, and having some flexibility for adherence purposes. An externally-located tubular metallic preferably finned heat-exchanger or cooling condenser, having a tubular central hub portion, constitutes an extension of the inner, elongated, tubular, high-voltage terminal-lead, which is partially filled with a low-boiling-point cooling liquid or refrigerant, such as "Freon-11", for example. A massive metallic line-terminal connector is affixed to the terminal-lead intermediate the location of the heat-exchanger and the adjacent end of the body portion for additional heat-dissipation purposes. A pressure gauge is attached at the upper end of the heat-exchanger in vapor communication with the cooling liquid within the terminal-lead.

Dependencies are inferred from the claim text.