How much do you know about contactors?

Promulgator : TAIXIDate : 2018-11-10Views : 313

From the point of view of usage, Household Contactor can be divided into:

1. Industrial contactors are mostly general models. The common models are CJX2 series, CJ20 series and CJT1 Series in CJ series.
2. Architectural and household contactors, ABBESB series, Hummer HBC1 series, CHINT NCH8 series, Siemens 3TF series, Schneider ICT series, etc.

Household Contactor use the main contact to turn on and off the circuit, and use auxiliary contacts to execute control instructions. The main contacts usually have only regular open contacts, while the auxiliary contacts often have two pairs of contacts with normal open and normal closed functions. Small contactors are often used as intermediate relays to cooperate with the main circuit. The contact of the contactor is made of silver tungsten alloy with good electrical conductivity and high temperature resistance.

The action power of contactor comes from alternating current electromagnet. The electromagnet is composed of two silicon steel sheets. One of them is fixed and coils are coiled on it. There are many options for working voltage. In order to stabilize the magnetic force, the suction surface of the core and the short circuiting ring are added. The contactor is reset by spring after power failure. The other half is a movable core, which is constructed like a fixed core to drive the opening and closing of the main and auxiliary joints. The contactor above 20A is equipped with an arc extinguishing cover, which can quickly pull the arc to protect the contacts by utilizing the electromagnetic force produced when the circuit is disconnected.

The Household Contactor is made into a whole, and its shape and performance are also improving, but its function remains unchanged. No matter how far the technology develops, ordinary contactors still have an important position.

Detection of Din Rail Mounted Contactor!

The detection of the contactor is based on the resistance of the multimeter.

The resistance of normally open contacts and normally closed contacts is tested under normal conditions. The following figure is to test the resistance of the Din Rail Mounted Contactor's normally open contacts under normal conditions. Because the normally open contacts are open under normal conditions, the normal resistance should be infinite. When the digital multimeter detects the resistance of the contactor's normally closed contacts, the normal measured resistance value should be close to 0Ω. For contactors with linkage frame, press the linkage frame, the internal open contacts will be closed, the closed contacts will be disconnected, you can use a multimeter to detect whether this is normal.

Detect the resistance of the control coil. The resistance of the test control coil is shown in the following figure. The resistance value of the control coil should normally be several hundred euros. Generally speaking, the greater the power of the Din Rail Mounted Contactor, the greater the attraction force of the coil to the contacts (i.e. the current flowing through the coil) and the smaller the resistance of the coil. If the resistance of the coil is infinite, the coil will open, and the resistance of the coil is 0, which is short circuited by the coil.

3. The resistance of the normally open and normally closed contacts is detected by the control coil energizing. To detect the resistance of normally open contacts, the control coil of the contactor is energized. When the control coil is electrified, if the contactor is normal, it will make sound. At the same time, the open contacts are closed and the closed contacts are disconnected. Therefore, the resistance of the open contacts should be close to 0_, and the closed contacts should be infinite (when the digital multimeter detects, it will show the symbol "1" or "OL". If there is no change in the contact resistance measured before and after the control coil is energized, it may be that the control coil is damaged or the transmission mechanism is stuck.