Gas blast, puffer type circuit breaker with improved nozzle

摘要

A gas blast circuit breaker comprises an insulation nozzle for blowing extinguishing gas to an arc generated between a stationary contact and a movable contact. The nozzle has a throat section into and out of which one of the two contacts is movable and a divergent section provided downstream of the throat section. A slanting surface for increasing a reflectivity of energy intensity of the arc is formed on the divergent section of the nozzle. The nozzle is formed of a fluoroplastic material and boron nitride powder of not more than 15 vol. % is added as a filler.