NEMA contactors are made to standards designated by the National Electric Manufacturers Association (NEMA). Contactors are electromagnetic switches that open and close electrical circuits to turn multiple high-current connections on and off simultaneously. These electrically operated switches control high-voltage motors, machinery, equipment, and electrical systems. NEMA magnetic contactors have robust constructions that come in standard NEMA motor sizes and withstand harsh environments. They are serviceable with replaceable parts and have longer operational lives than IEC contactors.
Contactors combine with compatible overload relays to create motor starter assemblies. Compatible auxiliaries can be added to increase the functionality of contactors.