PROTECTIVE CIRCUIT FOR PROTECTION OF AN APPLIANCE, IN PARTICULAR AN ELECTRIC MOTOR, AGAINST THERMAL OVERLOADING

摘要

The invention relates to a protective circuit (1) for protection of an appliance, in particular of an electric motor, against thermal overloading, comprising a first and a second terminal (2, 3) for connecting a temperature detection element (4, 11); a detection unit (6) for detecting whether a resistance value of the temperature detector element (4, 11), which is connected between the first and the second terminals (2, 3), is in a first or a second resistance range; a short-circuit detector for identifying whether there is a short circuit between the first and the second terminals (2, 3); signalling outputs (8, 9) for emitting signal messages to an evaluation unit (14) when the detected resistance value is in the second resistance range and/or when a short circuit has been identified by the short-circuit detector (10); and a third terminal (12), which is connected to the second terminal via a predetermined resistance.