AC contactor often adopts three arc extinguishing methods: double fracture electric arc extinguishing, longitudinal slit zhi arc extinguishing and grid plate arc extinguishing. It is used to eliminate the arc generated by the moving and static contacts during the opening and closing process. Contactors with a capacity above 10A have arc extinguishing devices. The AC contactor also has auxiliary components such as reaction springs, buffer springs, contact pressure springs, transmission mechanisms, bases and terminals.

The working principle of the AC contactor is to use the electromagnetic force and the spring force to cooperate to realize the connection and breaking of the contact. The AC contactor has two working states: power-off state (release state) and energized state (action state).

When the attracting coil is energized, the static iron core generates electromagnetic attraction, the armature is attracted, and the connecting rod connected with the armature drives the contact action, so that the normally closed contact breaker is in the energized state; when the attracting coil is powered off, The electromagnetic attraction disappears, the armature is reopening, so that the normally open contact is closed, and released under the action of the position spring, all the contacts are reset, and the contactor is in a power-off state.