Circuit breaker enclosure gas venting system

Abstract

The present invention discloses a gas venting system for use in metallic enclosures housing electrical circuit breakers of the type having gas vents in the circuit breaker case for venting gases produced during the interruption of a fault current. The enclosure includes one or more covers which provide access to the interior of the enclosure and one or more vents through which the circuit breaker gases can exit the enclosure. The gas venting system includes a gas chute made from an electrically nonconductive and substantially flame retardant material. The gas chute is generally tubular and hollow in shape and has a breaker end aperture and at lease one vent end aperture. The apertures communicate with one another through the hollow gas chute. The gas chute is attached to an inside surface of the breaker enclosure such that when the enclosure cover is closed the breaker end aperture is in close proximity to and encloses the circuit breaker gas vents and the vent end aperture is in close proximity to and encloses the enclosure vents. Any gases produced by the circuit breaker during the interruption of a fault current and exiting through the gas vents in the breaker case must enter the gas chute through the breaker end aperture. The gas is then directed to the vent end aperture where it exits the enclosure through the enclosure vents.