Circuit breaker

摘要

An automatic switch of this type includes a switch latch for interrupting current, an overload tripping device and a short-circuit current tripping device for acting on the switch latch to trigger a current interruption. Generally there is also included at least one main contact device having at least one stationary contact and at least one movable contact, a movably supported contact lever attached to the at least one movable contact, and at least one arc quenching device associated with each main contact device. The improvement according to the invention includes a combination of an additional armature system having a magnet coil, a magnet core, a magnet armature and a striker pin. The striker pin is operable for directly striking the at least one movable contact lever and for lifting the at least one movable contact from the at least one stationary contact for a given limited time in the event of short-circuit currents, and the short-circuit current tripping device is in the form of a selective protection tripping device.