SMC-口口type contactor is mainly used in the electric system with AC 50Hz/60Hz,the maximum voltage 660 V, and the maximum current 800A.lt is used for long distance swich-on and of circuit and frequently-starting motor.

lf properly combined with thermal overload relay device, it can work as starter of motor to prevent overload or open-phase. Series of such contactors can be equipped with toy-brick type auxiliary heads, air time-delay heads and interlocking device to act as time-delay contactor,reversing contactor, switching contactor and star-delta starter.