What are the advantages, disadvantages and common faults of high-voltage vacuum contactors?

High-voltage vacuum contactors are mainly used to connect or cut off normal operating current, as well as remotely connect and disconnect AC motors, or frequently start and stop under low voltage. The high-voltage vacuum contactor is mainly composed of an insulating frame, a metal base, a transmission crank arm, an electromagnetic system, an auxiliary switch and a vacuum switch tube. The following introduces the advantages, disadvantages and common faults of high-voltage vacuum contactors:

Advantages and Disadvantages of High-voltage Vacuum Contactor

1. Advantages of the product

1) Strong arc extinguishing ability, good pressure resistance and long service life.

2) Small size, light weight and long maintenance cycle.

3) High manufacturing technology and high operating frequency.

2. Product shortcomings

In our lives, we use many high-voltage vacuum contactors. They produce very low noise during operation, and also save energy and protect the environment during use. However, their circuit has some shortcomings during the development process, mainly in the following aspects:

1) After the main contact of the contactor is disconnected, we cannot see that it has an obvious disconnection gap, so our daily maintenance work is inconvenient.

2) The high-voltage vacuum contactor does not have a locking device and is prone to accidents during operation. This is a problem that people urgently need to pay attention to during operation.

3) The contactor also has the problem of small breaking capacity, so in a high current environment, its contacts can be easily disconnected automatically.

4) When the circuit is disconnected, there may be problems with the current cutting off the voltage or re-igniting the voltage, which may easily cause the contactor to be damaged during use.

Failure analysis of high-voltage vacuum contactor

1. Unable to store energy

Mainly check whether the energy storage motor, driving mechanism and positioning parts are defective, because they are usually related to these three parts.

2. No closing action

Mainly check whether the closing electromagnet is engaged, whether the energy storage is in place, and whether the positioning piece operates normally.

3. Air closure

First check if there is any problem with the shutdown, and then check if there is any problem with the energy storage component.

4. Not opened

Check control and secondary components, including auxiliary switches and terminal blocks, for problems. If there is no problem, check whether there is a problem with the contactor body.

The working principle of the high-voltage vacuum contactor is: when the electromagnetic coil is energized, the armature drives the crank arm to rotate by controlling the voltage, thereby connecting the main contact in the vacuum switch tube. When the solenoid coil is de-energized, the main contacts open. Its vacuum switch tube mainly includes upper cover, lower cover, metal bellows and ceramic tube. 

Its shell is made of corrugated porcelain tubes, which are made of ceramic insulating materials. It is characterized by high mechanical strength, large creepage distance, heat resistance and impact resistance. In the vacuum switch tube, a pair of moving and static contacts are also encapsulated. The contacts are made of wear-resistant materials, which can avoid overvoltage and increase their service life. The electromagnetic system of the product adopts a twisted pair structure to meet the advantages of low operating noise and energy saving. In addition, the switching of the auxiliary switch allows the operator to operate conveniently.