Why should AC contactor be equipped with short circuit ring?

Because the attraction coil of AC contactor passes through single-phase alternating current, when the alternating current passes zero, the electromagnetic attraction is zero, and the armature is released instantaneously, so that the electromagnet produces vibration and noise. The electrical structure is easy to loose, so that the service life is reduced, and the poor contact of the contact leads to ablation or fusion welding. In order to eliminate this phenomenon, a self-contained loop is embedded on the end face of the stator core The copper ring of the circuit is called short circuit ring.