Contactors are divided into alternating current contactors (voltage AC) and direct current contactors (voltage DC). It is used in power, power distribution and power applications. In the broad sense, a contactor refers to an electric field that uses a current flowing through a coil to generate a magnetic field in industrial electricity, so that the contacts are closed, so as to achieve control of the load.
The AC contactor uses the main contact to control the circuit and the auxiliary contact to conduct the control circuit.
The main contact is normally open contact, while the auxiliary contact usually has two pairs of normally open contact and normally closed contact. Small contactors are often used as intermediate relays to cooperate with the main circuit.
The contacts of the AC contactor are made of silver-tungsten alloy, which has good electrical conductivity and high temperature ablation resistance.
The power of the operation of the AC contactor is derived from the magnetic field generated by the AC through the coil with iron core. The electromagnet core is formed by stacking two young silicon steel sheets in the shape of a mountain. select. In order to stabilize the magnetic force, a short-circuit ring is added to the attracting surface of the iron core. The AC contactor is reset by a spring after power loss.
The other half is a movable iron core, which has the same structure as the fixed iron core, and is used to drive the closing and opening of the main contact and the auxiliary contact.
Contactors above 20A are equipped with an arc extinguishing cover, which uses the electromagnetic force generated when the circuit is disconnected to quickly break the arc to protect the contacts.
The contactor can be operated at a high frequency. As a power on and off control, the maximum operating frequency can reach 1200 times per hour.
The service life of contactors is very high, the mechanical life is usually several million to ten million times, and the electrical life is generally several hundred thousand to several million times.
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What is an AC contactor
2019-12-23 09:22:47 8625 Clicks