What is the function of AC contactor? I believe that when we meet this problem, most of us don't know how to answer it. Some people even haven't heard the term "AC contactor". After all, most people don't have access to relevant fields, so they are not interested in knowing, but AC contactors are closely related to household electricity. Now I will tell you the function of AC contactor and its working principle.
In general, the function of AC contactor is to protect the circuit and allow a large current to pass through. The relay of AC contactor has over-current or ground protection function. When there is lightning on the line after thunder, it will cut off the load power supply to protect the circuit. We often encounter tripping in thunder days because of this reason.
AC contactor is a fully automatic control device. The main control object of AC contactor is motor, which is also widely used to control other electric loads, such as welding machine, capacitor, electric heater, lighting group, etc.
Electromagnetic AC contactor
Electromagnetic AC contactor is mainly composed of electromagnetic system, arc extinguishing system, contact system and other parts. If you want to understand its working principle, you have to say from these three structures.
Electromagnetic system: the electromagnetic system consists of electromagnetic coil and iron core, which can drive the contact to close and open.
Contact system: the contact includes main contact and auxiliary contact, which is the executive part of the contactor. The main function of the main contact is to make and break the main circuit and control some large current, while the auxiliary contact is used to meet the requirements of various control modes.
Arc extinguishing system: the arc extinguishing system is used to ensure that when the contact is disconnected from the circuit, the generated arc will be extinguished safely to avoid the damage of the contact caused by the arc.
Vacuum AC contactor
The arc extinguishing medium of vacuum contactor is vacuum, not any specific substance. Its main contact is in a special vacuum arc extinguishing tube. When the operating coil is connected to the power supply, the armature is closed, and the contact is closed under the self closing force of the contact spring and the vacuum tube; when the operating coil is disconnected from the power supply, the reaction spring overcomes the self closing force of the vacuum tube to make the armature fall and the contact is disconnected.
After reading the above content, you should know what the function of the AC contactor is and how it works. Although these knowledge is boring, it is not useless. I hope the above content can help the friends in need.
Zhejiang Xiyiyi Electrical Equipment Co., Ltd