Electrical a gas-blast circuit breaker has a dielectric strength improved

摘要

A puffer-type electrical circuit breaker is insulated by an SF6 insulating gas contained in a casing of moulded insulating material. The circuit breaker comprises a system of contacts, a pair of connection terminals electrically connected to the contacts by means of bushings passing through the wall of the casing in a perpendicular direction to the longitudinal axis, and means of fixing the casing to a metal support at ground or earth potential. The external lateral surface of the insulating casing comprises a plurality of longitudinal flanges designed to increase the creepage distance between the terminals and the support. The creepage distance value is greater than the distance in the air between the same parts.