Square D thermal overload relays provide motor overcurrent protection. The exclusive one piece melting alloy thermal unit is used in these relays to provide protection against overheating of the motor winding insulation due excessive over current. The melting alloy thermal unit to be used is determined by the full load current of the motor to be controlled, number of phases and the enclosure size. When 3 thermal units are properly installed the relay can be reset. Overload relay has a trip free reset mechanism. The output contact is replaceable. Maximum voltage rating of 600 V. Overload relay has a trip free reset mechanism. Relay has a maximum voltage rating of 600 VAC. This overload relay is 4.06 inches tall, 4.28 inches wide and 4.00 inches deep.