High-or medium-tension compressed-gas circuit breaker taking circuit-breaking energy from the arc

摘要

A high- or medium-tension compressed gas circuit breaker taking circuit-breaking energy from the arc, the circuit breaker being of the type comprising: a fixed assembly including main contacts (8a) and arc contacts (21a); a moving assembly including main contacts (26) and arc contacts (25); a blast volume (VI) including a piston (12) which moves on contact separation and urges compressed gas through a blast nozzle (7) which opens over the zone where a main arc forms when the arc contacts separate, and a set of auxiliary contacts (22a, 21c) in series with the arc contacts for creating an auxiliary arc in the volume (V2) situated behind the piston, the circuit breaker further including means (23, 24) for allowing the auxiliary contacts to separate only when the pressure in the blast zone reaches a predetermined threshold.