modular contactors should be wired like this! With working principle, wiring method and wiring diagram

How does the modular contactor work?

When the coil is energized, the static iron core generates electromagnetic attraction, and the moving iron core is sucked. Since the contact system is linked with the moving iron core, the moving iron core drives the three dynamic contact pieces to simultaneously act, the main contact is closed, and the main The auxiliary normally closed contact that is mechanically connected to the contact is opened, and the auxiliary normally open contact is closed, thereby turning on the power.

When the coil is de-energized, the suction force disappears, and the moving iron core linkage part is separated by the reaction force of the spring, so that the main contact is disconnected, the auxiliary normally closed contact mechanically connected with the main contact is closed, and the auxiliary normally open contact is disconnected. , thus cutting off the power.

The AC contactor can only be used in the AC line. If the AC contactor is to be connected to the DC, the result must be that the line is burned seriously and the equipment is burnt.

The main components of the AC contactor

(1) Electromagnetic system, including attracting coil, moving iron core and static iron core;

(2) The contact system comprises three sets of main contacts and one to two sets of normally open and normally closed auxiliary contacts, which are connected with the moving iron cores;

(3) Arc extinguishing device, generally large-capacity AC contactor is equipped with arc extinguishing device to cut off the arc quickly and avoid burning the main contact;

(4) Insulating housing and accessories, various springs, transmission mechanisms, short-circuit rings, binding posts, etc.

AC modular contactor wiring

The contactor is marked on the above (subject to the actual)

1L3L5L corresponds to 2T4T6T is the main contact

Corresponding coil has terminal A1A2

There are also auxiliary contacts that can be connected.

13, 14 indicates the auxiliary contact of the contactor, NO indicates normally open, that is, 13 and 14 are disconnected when no power is applied, and 13 and 14 are closed after energization. Placed in the control circuit part with the lock (parallel on the start button) to achieve continuous operation.

Commissioning of motor reversible operation control circuit

1. Check whether the wiring of the main circuit is correct. In order to ensure that the phase sequence of the motor can be reliably replaced when the two contactors are operated, the upper port of the contactor should be kept consistent during wiring, and the phase of the contactor should be phased.

2. After checking the wiring is correct, the power-on test, in order to prevent accidents during the power-on test, the motor wiring should be disconnected first. Pre-processing of fault phenomena;

1. Do not start; one of the reasons is to check whether the control insurance FU is open circuit, whether the thermal relay FR contact is wrong or the contact is bad, and the normally closed contact of the SB1 button is bad. The reason for the second button interlock is incorrect.

2. When the home AC contactor is activated, it will not be sucked; this is because the interlocking connection of the normally closed contact of the contactor is wrong, and the interlocking contact is connected to lock itself. The normally closed contact is the starting point. After the electric contactor of the contactor coil is sucked, the normally closed contact is disconnected, the contactor coil is discharged again, the normally closed contact is released, the contactor is turned on and the contact is closed, and the contact is disconnected, so ""哒 哒 "The contactor does not attract.

3, can not be self-locking a hand contactor is disconnected, this is because the self-locking contact wiring is wrong Motor reversible operation control circuit In order to enable the motor to rotate forward and reverse, two contactors KM1, KM2 can be used The phase sequence of the three-phase power supply of the motor, but the two contactors cannot be sucked. If the suction at the same time will cause a short-circuit accident of the power supply, in order to prevent such an accident, a reliable interlock should be adopted in the circuit.