The control principle of the AC contactor is very simple. When the coil is connected to the rated voltage, an electromagnetic force is generated to overcome the spring reaction force, attracting the moving iron core to move downward, and the moving iron core drives the insulating connecting rod and the moving contact to move downward to close the normally open contact and disconnect the normally closed contact. When the coil loses power or the voltage is lower than the release voltage, the electromagnetic force is less than the spring reaction force, the normally open contact opens, and the normally closed contact closes.
1. Electromagnetic mechanism: The electromagnetic mechanism consists of a coil, a moving iron core and a static iron core.
2. Contact system: The contact system of the AC contactor includes main contacts and auxiliary contacts. The main contact is used to switch the main circuit on and off, with 3 or 4 pairs of normally open contacts. The auxiliary contact is used to control the circuit, which plays an electrical interlocking or control role. There are usually two pairs of normally open and two pairs of normally closed contacts.
3. Arc extinguishing device: All contactors with a capacity of more than 10A have arc extinguishing devices. For small-capacity contactors, double-break bridge contacts are often used to facilitate arc extinguishing; for large-capacity contactors, longitudinal seam arc extinguishing covers and grid arc extinguishing structures are often used.
4. Other components: including reaction springs, buffer springs, contact pressure springs, transmission mechanisms and housings.
Post time: Jun-19-2024
