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Introduction of contactor

Jan 09, 2019

Divided into AC contactor (voltage AC) and DC contactor (voltage DC), it is used in power, distribution and electricity. Contactor in a broad sense refers to the use of industrial electricity coil current generated magnetic field, make contact closed, in order to control the load of electrical appliances.

Difference between ac contactor and dc contactor

(1) The core is different: the core of the ac contactor is superimposed with insulating silicon steel sheets, and made into a double E shape; The core of dc contactor is made of whole soft iron, which is u-shaped.

(2) The arc extinguishing system is different: the ac contactor USES the cutout arc extinguishing device, while the dc contactor USES the magnetic blow-out arc extinguishing device.

(3) The coil turns are differentThe coil turns of the ac contactor are few and the current is ac. The number of coil turns of dc contactor is more and the current is dc.

(4)If the ac and dc contactors are connected incorrectly, Connect the dc to the ac contactor, the coil will burn immediately. If the ac is connected to the dc contactor,the contactor unable to operate.

The function of the contactor

Often used in the motor as the control object, can also be used to control the factory equipment, electric heaters, working machine and various power units and other power load. The contactor can not only switch on and off the circuit, but also has the protection function of low voltage release. Contactor control capacity, suitable for frequent operation and remote control. It is one of the important components in automatic control system.

Contactor working principle

When the contactor coil is energized, the coil current will generate a magnetic field, and the magnetic field will cause the static core to generate electromagnetic suction to attract the moving core, and then drive the ac contactor to move. The normally closed contact is disconnected, while the normally open contact is closed. The two are linked. When the coil is cut off, the electromagnetic suction disappears and the armature is released under the action of the release spring, so that the contact is restored. The normally open contact is disconnected and the normally closed contact is closed. The working principle of the dc contactor is somewhat similar to that of the temperature switch.