Switchgear.

摘要

A switchgear comprises, in a housing containing an arc extinguishing gas, a pair of separable contacts 2, 3 defining therebetween an arcing region in which an electric arc is generated when the contacts are separated. A cylindrical wall 6 and an insulating nozzle 22 are provided for defining a gas storage chamber 9 around the stationary contact, communicating with the arcing region, for storing the arc extinguishing gas to be increased in pressure by heat from the arc. The insulating nozzle defines an opening through which the movable contact 3 movably extends and through which the pressurized arc extinguishing gas flows. Around the arcing region a magnet system 25 is disposed for generating a magnetic field in the opening of the gas storage chamber for rotating and elongating the electric arc generated in the arcing region upon current interruption. The magnet system is an outer annular magnet 26, an inner annular magnet 27, and a yoke 28. A novel design of the nozzle enhances the arc-extinguishing capability.