How does the contactor switch work and what is the working principle of the contactor?

Contactor working principle:

When the coil is energized, the static iron core generates electromagnetic attraction and engages the moving iron core, because the contact system is linked with the moving iron core, so the moving iron core drives the three moving contacts to run at the same time, and the contacts are closed, so as to connect the power supply. When the coil is de-energized, the suction disappears, and the linkage part of the moving core is separated by the reaction force of the spring, so that the main contact is disconnected and the power supply is cut off.

Only one wire is used for the control coil...

The working principle of the contactor is: when the contactor coil is energized, the coil current will produce a magnetic field, and the generated magnetic field will make the static iron core produce electromagnetic attraction to attract the moving core, and drive the AC contactor point action, the normally closed contact is disconnected, and the normally open contact is closed, and the two are linked.

When the coil is de-energized, the electromagnetic attraction disappears, and the armature is released under the action of the release spring, which restores the contact, the normally open contact is disconnected, and the normally closed contact is closed. The working principle of a DC contactor is somewhat similar to that of a temperature switch.

The AC contactor uses the main contact to control the circuit and the auxiliary contact to turn on the control loop. The main contact is generally a normally open contact, while the auxiliary contact often has two pairs of normally open contact and normally closed contact, and the small contactor is often used as an intermediate relay 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 schematic diagram is as follows:

AC contactor is the most widely used low-voltage control appliance in electric drive and automatic control systems. As an actuator, it is used to turn on and break lines, or frequently control the operation of equipment such as motors. It is composed of dynamic and static main contacts, arc extinguishing covers, dynamic and static iron cores, auxiliary contacts and bracket shells.

After the electromagnetic coil is energized, the moving iron core is engaged under the action of electromagnetic force, and the moving contact is in contact with the static contact directly or through the lever transmission, and the circuit is connected. After the solenoid coil is de-energized, the moving iron core automatically returns under the action of the return spring, commonly known as release, the contact is separated, and the circuit is broken.

In all industrial equipment, the contactor may not be the one you are most familiar with, but it is a widely used equipment in our daily life, in electrical engineering, the contactor has a close relationship with the current guidance and use, so it can be innovatively applied in various occasions, when necessary, there is also a low voltage release protection of the spike oak staring effect. So how does a contactor work?

The working principle of the contactor is as follows: when the coil is energized, the static iron core generates electromagnetic attraction, so that the moving iron core is sucked, and then drives the three moving contacts of the contact system to act, the main contact is closed, the auxiliary normally closed contact is disconnected, and the auxiliary normally open contact is closed and the power supply is connected.

When the coil is de-energized, the electromagnetic attraction of the static iron core disappears, and the reaction force of the spring separates the moving iron core from the static iron core, and the three moving contacts of the contact system make the main contact disconnected, the auxiliary normally closed contact is closed, and the auxiliary normally open contact is disconnected to cut off the power supply.

1. Generally, the three-phase contactor has a total of 8 points, three inputs, three outputs, and two control points. The output and input are corresponding, and it is easy to see. If self-locking is to be added, it is necessary to connect the wire from one of the terminals at the output point to the control input point.

After knowing the principle, you should figure out the contacts of the external power supply, that is, the two contacts of the coil, which are generally in contact with the lower part of the guesser, and each on one side. The other inputs and outputs are generally in the upper part, and you can see it at a glance. Also pay attention to what the voltage of the external power supply is (220V or 380V), which is generally marked as having it.

And pay attention to whether the contact point is normally closed or normally open. If there is a self-locking control, it is enough to sort out the line according to the principle.

1. The essential difference between the relay and the contactor is that the load is different, the contactor with a large current capacity is the relay, and the difference is between the contactor used in the main circuit and the relay used in the control loop.

2. The function of the contactor is to turn on and break large current signals and drive power equipment such as motors;

3. The function of the relay is to convert the signal, and the interface between the equipment of different voltage levels to control the signal, the contact carrying capacity is generally small, and it is used to drive the contact such as the hole and other electrical components.

Contactors are the most widely used electrical appliances in electrical transmission and automatic control systems, and their common appearance is shown in Figure 6-6. As an actuator, it can automatically control the start, operation, commutation and stop of the motor from a distance and frequently.

a)cj10-10(b)cj10-60(c)cj20-40(d)3tb/3th

AC contactors and DC contactors have the same principle of operation. Both are driven by the magnetic potential generated by the electromagnetic coil on the yoke (or core) when the current passes through the moving armature, either directly or through the lever transmission, and the moving and static contacts are in contact to complete the circuit. When the coil is de-energized, the moving contact returns to its original position under the reaction force of the spring, thus disconnecting the circuit.