Current interrupting switch unit with current interrupting switch contacts e.g. for protection of machine tool induction motors

摘要

The unit contains a switch housing (12) with several switch contacts for interrupting a circuit current. The housing also contains an actuating mechanism for separating the contacts, and a trigger unit for swivelling the actuating mechanism, when an overcurrent state appears in the circuit to be protected. There is at least one current limiting housing (32) near to the switch housing, and at least one current limiting element (26) coupled to the switch contacts, through which the circuit current flows. On appearance of an overcurrent condition, the current is limited to a preset value. Pref. the trigger unit has electronic components monitoring and responding to the overcurrent condition.