The FZN25-12 vacuum circuit breaker is widely used in high-voltage transmission circuits due to its excellent isolation capabilities. The vacuum interrupter chamber of the high-voltage vacuum circuit breaker is its core, as the performance and service life of the vacuum circuit breaker largely depend on the quality of the interrupter chamber. If the chamber experiences chronic leakage, the vacuum level will decrease, leading to a deterioration in the breaker's opening performance and a shortened service life. Therefore, it is necessary to inspect it after a certain period of operation. If vacuum measurement is not possible, most inspections are conducted through the application of power frequency withstand voltage tests. The specific method is as follows: first, disconnect the power supply and place the vacuum circuit breaker in the open position. Then, apply power frequency voltage to both ends of the static contact of the vacuum circuit breaker. If there is no discharge or breakdown, it indicates that the vacuum level of the interrupter chamber has not decreased and can continue to be used.

Therefore, when selecting the FZN25-12, it is crucial to prioritize the quality of the arc-extinguishing chamber to ensure it meets people's demands.