AC contactor is a kind of contactor widely used in the opening and closing of electric power and control circuit. It uses the main node to open and close the circuit, and uses the auxiliary contact to execute the control command. The main contact generally only has a normally open contact, while the auxiliary contacts often have two pairs of contacts with normally open and normally closed functions. Small contactors are often used as intermediate relays to cooperate with the main circuit. Today we briefly understand the little knowledge of the exchange contactor, hope it will be helpful to you.
The contact of the AC contactor is divided into three parts: main contact, auxiliary contact, coil;
Main contact wiring
135 is the incoming terminal, and 246 is the outgoing terminal; that is to say, we need to connect the power supply to the 135, while the 246 is to connect the load. So knowing the location of the wiring, we now need to know the voltage level of the main contact. Normally, the voltage level will be on the side of the contactor. The contactor can be connected to a three-phase line of 220 volts, 380 volts, and 660 volts. And the rated current must match the number below (220V and 380V rated current is 18A, if it is connected to 660V, then the rated current will be reduced to 12A).
Auxiliary contact
If the auxiliary contact is written “no”, it means it is a normally open point, which will be used when connecting to a self-locking circuit. And “nc” represents the normally closed point, we need the normally closed point when connecting the interlock circuit.
Coil
The coil is generally on the top, and the a1 and a2 marks are found at the top position. Most AC contactors have two a2s, and the insides of these two a2s are connected together and communicate with each other. The coil level is generally displayed around the coil. The coil level and the voltage level of the main contact are different, but when our coil is energized, the main contact will be closed and the main circuit will be connected. The main contact of the AC will appear in the main circuit, and the wiring of the auxiliary contact and the coil will appear in the control circuit. Here we need to distinguish.
Speaking of this, perhaps everyone has a general understanding of the AC contactor, and we hope that what we have described can help you when you need it.
