The Advantages and Failure Causes of Vacuum Contactors

The vacuum contactor has strong arc extinguishing ability, good pressure resistance, high operating frequency, long life, no arc spray, body，Small size, light weight, long maintenance cycle. The process requirements for the vacuum interrupter of the vacuum contactor are very high. If the process is poor, the vacuum of the interrupter is easy to drop. Contact material material is bad, the breaking current will be "closure when over-voltage " phenomenon, that is, when the breaking current, due to the strong extinguishing capacity of the vacuum interrupter, the electric arc current is not cut off natural zero crossing, but from A certain value of the current suddenly drops to zero, resulting in a high overvoltage. The cut-off voltage will endanger the safe operation of electrical equipment.

Whether the vacuum contactor is faulty or not can be judged according to whether it can be closed and opened accurately and reliably and maintained at the closed and open positions. The failure of the main circuit can be found and eliminated from the routine inspection and maintenance of the contactor.

The main causes of common failures are analyzed as follows:

Inability to store energy: Inability to store energy is one of the more common failures of vacuum contactors, especially the energy storage mechanism driven by ratchets and pawls, which has a higher probability of failure. The energy storage mechanism to complete the energy storage action mainly depends on the three links of the energy storage motor, the drive mechanism, and the positioning parts. Grasping these three links closely, it is easy to find the crux of the fault.

No closing action: The occurrence of a no closing action fault is mainly related to whether the closing electromagnet is closed, whether the energy storage is in place, and whether the positioning member is operating normally.

Air close: There is a closing action but the brake is not closed, it is called open close. When analyzing this type of fault, we should first start with the analysis on the closing and holding (locking), and then analyze whether it is related to the energy storage part.

No opening: It should be emphasized here that when the contactor refuses to move, dry close, etc., before analyzing and repairing the main body of the contactor, it is necessary to fully judge whether the cause is in the control and secondary components such as auxiliary switches , terminal blocks, etc. Aspect, and then analyze and diagnose the contactor.

As a supplier of high-quality vacuum contactors, our product series include JCZ8G, JCZ8C, JCZ5, CZN85Y and other series of vacuum contactors.

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