DEVICE FOR PROTECTING A MOTOR AND EQUIPMENT DRIVEN BY THE MOTOR

The proposed device for protecting a motor and working equipment driven by the motor contains a transformer current transducer for the motor, a magnetic starter for starting the motor, an actuating relay, a temperature transducer for the motor, a unit for forming the characteristic of the motor current as a function of time, a unit for protecting the motor against overheat, and additionally, a unit for protecting the motor against the removal of the load of the working equipment, a unit for preventing the start of the motor at the reduced insulation resistance of the motor winding, and an OR logic element. The outputs of the said protecting units and the output of the current transducer are connected to the corresponding inputs of the OR logic element. The coil of the actuating relay is connected to the output of the OR logic element. The contacts of the relay are inserted in the control circuit of the magnetic starter.