When a JDS Products model 1999 SENSING-SAF-START® is installed on any equipment and there is an electrical power interruption to the equipment, the SENSING-SAF-START® will open the circuit so when the power source is restored, the SENSING-SAF-START® will prevent the equipment from restarting. Use this unit on all 200-240VAC single phase (3-wire) machines. You must install any matching plugs on the power cord.