CJX2 AC contactor usually has two groups of auxiliary contacts, one is normally open and the other is normally closed, which are used to form logic circuit, such as self holding circuit, exclusive OR gate (interlock) circuit, priority circuit, etc. The capacity of auxiliary contact is usually small, which is used for control.

Main contact and auxiliary contact of CJX2 AC contactor

1) Contacts

In the process of contactor action, the contact points of those conductors that are connected or disconnected with the contactor closing or reset are called contacts.

2) Main contact

The main contact of the contactor is the contact part of the conductor that supplies power to the main circuit. The cross section of the contact point between the conductor and the conductor is designed to be larger, which can flow through a larger current (generally, the main contact of CJX2 AC contactor can flow through 9 ~ 630A). In order to avoid short circuit between the contacts caused by arc when the contactor acts, an arc extinguishing cover is also designed between the main contacts.

3) Auxiliary contact

Auxiliary contact is used for signal transmission or control, so its current carrying capacity is relatively small, generally only 2 ~ 5a, and there is no arc extinguishing cover.

The main contact is to control the on-off of electrical appliances (such as motor), which can allow a lot of current to pass through. Some also have contact arc extinguishing device to eliminate the arc generated when the contact is on-off.

Auxiliary contact is used for control, such as the need to do self-locking, interlocking circuit with auxiliary contact to do. The current allowed by the auxiliary contact is very small. The main contact is the main circuit of the controlled equipment. The rated current is determined according to the model of CJX2 AC contactor. For example, cj20-40cjx2 AC contactor, the rated current of main contact is 40A

The auxiliary contact is the conduction control circuit. The current passing through is generally 1 ~ 5A

The contact of main contact and auxiliary contact will be different in material and size.

Function and application of main contact and auxiliary contact of CJX2 AC contactor

Basic functions of CJX2 AC contactor: after the CJX2 AC contactor is powered on, the main contact is closed, the circuit is connected, the normally open point in the auxiliary contact is closed, and the normally closed point is disconnected, so as to make the circuit produce certain dynamic changes and control the normal operation of the circuit.

1. Main contact function.

The main contact is connected in series in the main circuit (mostly motor) to connect or disconnect the circuit, so as to control the circuit (motor operation). The function of the main contact is relatively simple.

2. Auxiliary contact function.

(1) Form a self-locking circuit. Self locking circuit is an essential and most widely used basic circuit in power control

When the start button SB2 is pressed, the KM coil of CJX2 AC contactor is powered on and closed. In the corresponding main circuit, the main contact km of CJX2 AC contactor is closed to connect the circuit, and the auxiliary normally open contact is closed to form self-locking, so as to ensure that the circuit still keeps working after the start button SB2 is released.

In practical application: the self-locking circuit uses the normally open contact of the contactor, which is in parallel with the start button.

(2) Form interlock circuit.

Contactor interlock circuit is also a basic circuit widely used