Automatic gas blast circuit breaker with nonreturn valve - has snap action valve releasing full cross section of supply line on quenching gas overpressure

摘要

The circuit breaker has a pumping system (2) for compression of the arc quenching medium. The compressed medium is supplied via a channel to a nozzle of insulating material. A non-return valve (1) is mounted in the medium channel in front of the nozzle. The non-return valve is of snap-action design matched to a preset quenching medium pressure in the pumping system. Only after the preset pressure has been exceeded, the non-return valve releases the entire cross section of the channel (3) in the direction to the nozzle (4) within several milliseconds. Pref. the valve body (5, 10) is held in closed position by at least one holding magnet (6, 7, 19), typically a permanent magnet. The latter can consist of several annular, alternately poled permanent magnets with iron strips (8) between their poles (N, S).