The Main Structure of a Contactor

A contactor primarily consists of three main components: an electromagnetic mechanism, a contact system, and an arc-extinguishing device. The electromagnetic mechanism comprises a coil, a core, and an armature; when the coil is energized, it generates a magnetic field that attracts the armature, thereby actuating the contacts to close or open and enabling control over the electrical circuit. This mechanism constitutes the core structural element that enables the contactor to perform automated operations.

The contact system consists of main contacts and auxiliary contacts. The main contacts are primarily utilized to make and break the main circuit and are capable of carrying substantial operating currents; the auxiliary contacts, conversely, are employed for signal transmission and interlocking control within the control circuit. The contacts are typically fabricated from alloy materials possessing superior conductivity to enhance their current-carrying capacity and extend their operational lifespan.

To mitigate equipment damage caused by the electrical arcs generated when the contacts interrupt a circuit, the contactor is also equipped with an internal arc-extinguishing device. Common arc-extinguishing methods include air-blast quenching and vacuum quenching. This device functions to rapidly extinguish the arc, thereby preventing contact erosion and enhancing both the safety and operational reliability of the contactor.