3RV1021 Motor Starter Protectors (MSP’s) are built for a world of applications while meeting the requirements of control users worldwide. Each MSP features a manual ON/OFF switch, a Class 10 adjustable bimetallic overload relay and magnetic trip elements for short circuit protection. , 3RV1021 motor starter protectors are equipped with bimetallicbased, inverse-time delayed overload releases - electromagnetic short-circuit releases. The overload releases can be set in accordance with the load current. The overcurrent releases are permanently set to a value 13 times the rated current and thus enable trouble-free start-up of motors.