METHOD AND DEVICE FOR THE SECURE OPERATION OF A SWITCHING DEVICE

摘要

The invention relates to a method and to a device for the secure operation of a switching device comprising at least two main contacts which can be switched on or off, and which, respectively, comprise contact pieces and a displaceable contact bridge, and at least one control magnet which comprises a displaceable anchor. The anchor acts upon the contact bridge when it is switched on or off such that the corresponding main contact is opened or closed. The method comprises the following steps: a) a circuit monitoring agent is transferred in a first state if the main contacts are closed when switched on, b) the circuit monitoring means remain in said first state after switching off if at least one of the main contacts is welded.