Contactor

■  Overview

AC contactors, also known as electromagnetic switches, have been widely employed in the application of power control. The operating principle of AC contactor is attained by providing current to the windings of the contactor to induce a magnetic field in order to manipulate the contact switch of the AC contactor to open or close, thereby controlling the power appliance. As the AC contactor is durable in large-current applications where the maximum allowable current is as high as 800amps, and is able to readily and frequently turn on or off the power supply for high-current power appliance, e.g. 380 V AC, the AC contactor is commonly used to control the electromagnetic motor with high startup current. The AC contactor can also be employed to control factory equipment, electric heater, metal working machine, or auto-control electric apparatus, thereby fulfilling the purpose of remotely controlling the power appliance or automatically controlling the power appliance.

■  Contact materials

（1）For a less than 32 amp circuit load, rivets are often made from AgCdO12 and AgNi10

（2）For an over 32 amp (32 amp included) circuit load, contact tips are made from AgCdO15 or environment-friendly AgSnO₂ and AgSnO₂In₂O₃ for RoHS in sheets. In some cases, AgCdO12 sheet is used.