PMA-4000 series electromagnetic contactors are designed for use in stationary installations for remote starting, stopping, and reversing of three-phase squirrel-cage induction motors with a voltage up to 660 V AC 50 and 60 Hz. When equipped with thermal relays, the contactor protects the controlled electric motors from: * overload; * currents arising from a single-phase break; * phase asymmetry. * Contactors feature high mechanical and switching endurance, ensuring a long service life even under intensive operation; * Complies with GOST requirements for industrial equipment, ensuring high reliability of operation; * No noise and increased operational reliability; * Simple design and high reliability, proven by operational time.