PLC controls the relay and how to wire the contactor.

PLC controls the coil of relay, just string the power supply on the contact of relay and then connect it to the coil of contactor.

The input of the control relay is usually electrical quantities such as current and voltage, and it can also be non-electrical quantities such as temperature, pressure and speed, while the output is the electrical signal sent out when the contact moves or the parameter change of the output circuit. The characteristic of relay is that when its input changes to a certain program, its output will change gradually.

Extended data:

When the coil is energized, the moving iron core is attracted to the conical stopper and drives the cross beam, so that the moving contact brackets on both sides move upward, and the contact switching is realized. After the coil is cut off, the moving iron core and the moving contact bracket are restored to their original positions under the action of the reaction spring.

When the contactor coil is energized, the coil current will generate a magnetic field, and the generated magnetic field will make the static iron core generate electromagnetic attraction to attract the moving iron core, which will drive the AC contactor to move, so that the normally closed contact will be disconnected and the normally open contact will be closed, which are linked.

When the coil is powered off, the electromagnetic attraction disappears, and the armature trips under the action of the trip spring, so that the contacts are reset, the normally open contacts are disconnected, and the normally closed contacts are closed. The working principle of DC contactor is somewhat similar to that of temperature switch.

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