A contactor relay is an electromagnetic switch used to switch on or off electrical circuits; contactor relays can handle high volume current and usually have overload protection. Contactors are typically used to start motors or heating elements which require sustained currents, unlike relays which generally are used to switch devices on or off. Isolating the source of the issue is a crucial step in the resolution process. A qualified technician is the best able to determine the nature of the fault and Norris Spares can help with the replacement part!