Contactor. A75 contactors are mainly used for controlling 3-phase motors and generally for controlling power circuits up to 690 V AC / 1000 V AC or 220 V DC. The contactors can also be used for many other applications such as isolation, capacitor switching, lighting. The A... series 1-stack 3-pole contactors are of the block type design. - Main poles and auxiliary contact blocks: 3 main poles, front and side-mounted add-on auxiliary contact blocks - Control circuit: AC operated with laminated magnet circuit