The appearance of AC contactor is slightly different according to the famous brand. For common domestic AC contactors, there are 6 or 7 groups of terminals (two on the left and right are considered as one group, one in and one out). The terminal signs are L1, L2, L3, no, NC, A1 and A2 respectively. In recent years, basically all AC contactors have two terminals marked as A1, two A1 are internally connected, one is above the AC contactor, and the other is directly below.

It is convenient for wiring in application and can be used as the same terminal. Among them, the time delay relay is L1, L2, L3, no; the normally closed point is NC; A1 and A2 are respectively the incoming line and outgoing line of the electromagnetic coil of AC contactor. Many people can't remember no and NC all the time. In fact, the memory is very simple. N stands for normally, which is translated as "Chang" in Chinese; O stands for open, which means "open"; C stands for close, which means "close". No and NC are usually used in self-locking and self-locking interlock of control circuit.