DEVICE FOR CONTROLLING TEMPERATURE COMPENSATION OF MOTOR STARTER

PROBLEM TO BE SOLVED: To provide a device for controlling the temperature compensation and protection of a motor starter which does not require any particular additional element like a bimetal. SOLUTION: A device 10 for controlling the temperature compensation of a motor starter is arranged to detect ambient temperature with an ambient temperature sensor 36 and to supply a motor starter 12 with ambient temperature signals. Additional temperature sensors 30, 32, 34 are mounted to perform heat transfer with each of bus bars 22, 24, 26 inside the motor starter 12, and the temperature of each pole is monitored. A microprocessor 28 is connected to each of the temperature sensors 30, 32, 34, 36, for monitoring the change of the operating temperature inside the motor starter 12 periodically and receiving the temperature signals. If the ambient temperature rises or if the internal resistance of the device rises with the temperature, the output of the motor starter 12 is adjusted by the controlling device 10 based on the change of the operating temperature to maintain a constant output.