In electrical engineering, because it can quickly cut off AC and DC main circuits and can frequently switch on and off large current control (up to 800A) circuits, it is often used in motors as control objects and can also be used as control plants. For electrical loads such as equipment, electric heaters, working mothers and various power units, contactors can not only connect and cut off the circuit, but also have a low-voltage release protection function. The contactor has a large control capacity and is suitable for frequent operation and remote control. It is one of the important components in the automatic control system.
In industrial electrics, there are many types of contactors, with operating current ranging from 5A to 1000A, and their usefulness is quite extensive.