Inventors:
Charles J. Tennies - Waukesha WI
Richard J. Fons - Milwaukee WI
Assignee:
Eaton Corporation - Cleveland OH
International Classification:
H01H 4700
Abstract:
Upon initiation of operation of a contactor from an unactuated condition to an actuated condition, the maximum magnitude of an initial current conducted to the coil of the contactor is determined. Once the contactor has been operated to the closed condition, the holding current is checked to determine if it exceeds a reference current. The reference current is a predetermined function of the maximum initial current. If the reference current is less than the holding current, a malfunction signal is provided. In another embodiment of the invention, a sensor is provided to sense the position of movable contacts connected with an armature of the contactor.