Contactors are divided into AC contactors (voltage AC) and DC contactors (voltage DC), which are used in power, distribution and electricity occasions.In a broad sense, the contactor refers to the industrial electrical appliances that use the coil to flow through the current to generate a magnetic field and close the contacts to control the load.
In electrology, because can quickly cut off ac and DC main loop and can frequently turn on and high current control (up to 800A) circuit, so often used in the motor as a control object can also be used as the control plant equipment heater generator and various power load, contactor can not only turn on and cut off the circuit, but also have low voltage release protection effect.Conactor control capacity is large, suitable for frequent operation and remote control, is one of the important components in automatic control system.
In industrial electricity, there are many models of contactors, and the working current varies in 5A-1000A, and its use is quite widespread.
Contractor mechanism works
The working principle of the contactor is: when the contactor coil is energized, the coil current will produce magnetic field, the magnetic field makes the static core produce electromagnetic suction to attract the core, and drive the AC contactor point action, often close the contact disconnected, often open the contact closed, the two are linkage.When the coil is powered off, the electromagnetic suction disappears, and the armature is released under the action of the release spring, making the contact recover, the often open contact is disconnected, and the often closed contact is closed.DC contacts work in a somewhat similar way to a temperature switch.AC contactor wiring method
1,3,5 For three-phase power supply, (main circuit part)
2,4, and 6 Connect to the three-phase motor
A1, A2 are the coils of the contactor, connected to the control circuit, and the motor controlling the circuit (large) by controlling the coil of the contactor (A1, A2).
13,14 Represents the auxiliary contact of the contactor, and NO is normally open, meaning 13,14 is disconnected, and 13,14 is closed after power-on.In the control circuit part with the lock (parallel on the start button), to achieve the purpose of continuous operation.
Firstly, the main three power contacts L1, L2, L3 of the contactor, and then three wires from T1, T2, T3 of the contactor, above is the main circuit.
Control circuit: from L1 lead to a wire connection stop button (stop button is often closed, start button is often open, this should know!) From the stop button to one end of the start button and the contactor auxiliary contact, and then from the other end of the other end of the auxiliary contact (this part is self-locked), the coil A1 and the coil A2 connect L2 or L3.
First of all, we first understand several basic knowledge of Schneider AC contactor has two basic things, the main contact and auxiliary head, the main contact is used to contact with electrical appliances or connected to the main circuit, auxiliary contact is connected to the control circuit, used to control the main circuit.
The main contact is generally connected to the main circuit, as for the order when there is no special requirements, the auxiliary contact is connected to the control circuit, generally to choose whether often open contact point or often closed contact point.This choice is based on the requirements of the control loop. Generally, if an AC contactor is often open and closed contacts are not enough, take Schneider as an example, an organization can be added at the top.Similar to normally open and closed contacts are available for use.
The judgment of the AC contactor is often open and often close the switch range can use the universal table, when the universal table measurement is sound to prove the constant closed contact, when the universal table is not sound is often open contact, press the auxiliary button often open will ring, often closed will not ring.
Post time: May-26-2022
