What is the function of the AC/DC contactor? The function of the contactor is to use a small current to control a large current load, which can be controlled remotely, and at the same time can be self-locked and interlocked to prevent accidents caused by misoperation. Because of the small current control, the protection circuit is simple and reliable.

Electric silver contacts and copper terminal are the key parts of contactor.Contactors are divided into AC contactors (voltage AC) and DC contactors (voltage DC), which are used in power, distribution and consumption. In a broad sense, a contactor refers to an electrical appliance that uses a coil to flow through a current to generate a magnetic field to close the contacts in order to control the load in industrial electricity.

Contactor Features

The contactor has the advantages of high operating frequency, long service life, reliable operation, stable performance, low cost, and easy maintenance. It is mainly used to control motors, electric heating equipment, electric welding machines, capacitor banks, etc. One of the widest range of control appliances.

Contactors can be divided into AC contactors and DC contactors according to the type of current passing through their contacts.

The principle of contactor

The contactor is mainly composed of electromagnetic mechanism, contact system and arc extinguishing device. The electromagnetic mechanism is a "sensing" element, and when it senses a certain "electrical signal", it will drive the contacts to close or break. It mainly includes coil, iron core and armature.

The working principle of the contactor, when the coil is powered off, the electromagnetic attraction of the static iron core disappears, the reaction force of the spring separates the moving iron core from the static iron core, and the three moving silver contact pieces of the contact system act, making the main contact disconnected , the auxiliary normally closed contact is closed, the auxiliary normally open electric silver contact is disconnected, and the power is cut off.

As shown in the figure below, the principle of closing the main circuit: turn on the power supply → the coil is energized → the magnetic flux is generated in the iron core → the electromagnetic suction force is generated → the electromagnetic suction force overcomes the spring force → the armature is pulled in → the contact mechanism action → the main electrical silver contact is closed → the main The loop is on.