Reasons and treatment methods for the reduction of vacuum degree of vacuum circuit breaker

The vacuum circuit breaker breaks the current and extinguishes the arc in the vacuum bubble, and the vacuum circuit breaker itself does not have a device for qualitatively and quantitatively monitoring the characteristics of the vacuum degree, so the vacuum degree reduction fault is a recessive fault, and its danger is far greater than the dominant fault. .
 Cause Analysis
The main reasons for the reduction in vacuum are as follows:
(1) There is a problem with the material or production process of the vacuum bubble, and there are tiny leaks in the vacuum bubble itself;
(2) There is a problem with the material or manufacturing process of the corrugated tube in the vacuum bubble, and leakage occurs after repeated operations;
(3) Split type vacuum circuit breakers, such as vacuum circuit breakers using electromagnetic operating mechanisms, during operation, due to the relatively large distance of the operating connecting rods, which directly affects the characteristics of the switch, such as synchronization, bounce, and overtravel, reducing the degree of vacuum. speed up.
Malfunction Hazard
The reduction of vacuum degree will seriously affect the ability of the vacuum circuit breaker to interrupt the overcurrent, and cause the service life of the circuit breaker to decrease sharply, and in severe cases, the switch will explode.
 Approach
(1) During the regular power outage maintenance of the circuit breaker, a vacuum tester must be used to conduct a qualitative test of the vacuum degree of the vacuum bubble to ensure that the vacuum bubble has a certain degree of vacuum;
(2) When the vacuum degree decreases, the vacuum bubble must be replaced, and the characteristics tests such as stroke, synchronization and bounce must be done.
Precaution
(1) When selecting vacuum circuit breakers, mature products produced by reputable manufacturers must be selected;
(2) Select the vacuum circuit breaker with the body and the operating mechanism integrated;
(3) When inspecting, operators should pay attention to whether there is discharge phenomenon outside the vacuum bubble of the circuit breaker. If there is a discharge phenomenon, the vacuum degree test result of the vacuum bubble is basically unqualified, and the power outage should be replaced in time;
(4) When the maintenance personnel carry out power failure maintenance work, they must carry out characteristic tests such as synchronization, bounce, stroke, and overtravel to ensure that the circuit breaker is in good working condition.