Before we understand the wiring of contactor self-locking, we should first understand the principle of contactor, and the normally open and normally closed contacts. We don't know anything about these wiring. Let's first explain the principle and structure of contactor.

380伏交流接觸器有三個主觸頭也就是電源進線和負載端出線，進線分別是三相火線L1L2和L3,負載端出線分別是T1T2和T3,接觸器主觸頭進線和出線上下一一對應，分別是L1對應T1,L2對應T2L3對應T3,主觸頭在接觸器不吸合的狀態下是常開狀態.

380 V AC contactor has three main contacts, that is, power supply incoming line and load end outgoing line. The incoming line is three-phase live line L1L2 and L3 respectively, and the load end outgoing line is t1t2 and T3 respectively. The incoming line and outgoing line of main contact of contactor are one-to-one corresponding, L1 corresponding to T1, L2 corresponding to t2l3 corresponding to T3 respectively. The main contact is normally open when the contactor is not closed

什么是常開？常開的意思就是說觸點是斷開的，不聯 通的，常閉的意思就是說觸點是聯

What is normally open? Normally open means that the contact is open, not connected, normally closed means that the contact is connected

通的，常開和常閉一定要充分理解才可以

General, normally open and normally closed must be fully understood

接觸器還有一個常開輔助觸頭，也就是右方的第四個接觸器觸點，上下也是一一對應，接觸器不吸合一直是常開狀態，輔助觸頭的作用就是輔助按鈕控制接觸器的，而主觸頭的作用是控制負載端的，所以分為主觸頭和輔助觸頭。

The contactor also has a normally open auxiliary contact, that is, the fourth contact on the right, which is one-to-one corresponding to the top and bottom. The contactor is always normally open when it does not pull in. The function of the auxiliary contact is to control the contactor by the auxiliary button, while the function of the main contact is to control the load end, so it is divided into the main contact and the auxiliary contact.

那接觸器怎樣才能吸合運轉呢？要想接觸器吸合那只有讓接觸器線圈通電，接觸器才會吸合，交流接觸器線圈電壓有220伏的也有380伏，線圈電壓接線的兩個觸點分別是A1和A2，也就是說線圈A1和A2只要有電，形成220伏或者380伏電壓接觸器就會吸合，這樣應該很好理解。

How can the contactor pull in and operate? In order to pull in the contactor, only when the contactor coil is energized can the contactor pull in. If the coil voltage of AC contactor is 220 V, it also has 380 v. the two contacts of coil voltage wiring are A1 and A2 respectively. That is to say, as long as the coil A1 and A2 are energized, the contactor will pull in when it forms 220 V or 380 V. This should be well understood.

線圈的位置在接觸器的后方中間的位置，它的作用就是通電以后線圈產生電磁，而在接觸器前方中間的位置有塊銜鐵，接觸器線圈通電產生電磁以后開始吸住前方銜鐵，而銜鐵又推動接觸器主觸頭和輔助觸頭的上下觸點，所以接觸器常開觸點變為常閉觸點，常閉觸點會變為常開觸點。

The position of the coil is in the middle of the back of the contactor. Its function is to generate electromagnetic field after the coil is electrified, and there is an armature in the middle of the front of the contactor. After the contactor coil is electrified, it begins to absorb the armature in front, and the armature pushes the upper and lower contacts of the main contact and auxiliary contact of the contactor, so the normally open contact of the contactor becomes normally closed contact, The normally closed contact will become normally open.