At present, vacuum switch has been widely used in various fields at home and abroad, with the popularization and improvement of the use of vacuum switch, the majority of users are more and more urgent to understand and master the principle, structure, use and maintenance of vacuum switch knowledge, this paper combined with practical experience theoretically analyzed the selection principle and experience data of vacuum circuit breaker mechanical parameters. For the majority of users to better use the vacuum switch to provide some technical reference.



1
Rated opening
When the vacuum circuit breaker is in the opening state, the distance between the dynamic and static contacts of the vacuum switch tube is related to the rated voltage of the vacuum circuit breaker, the use conditions, the nature of the breaking current, the contact material, the pressure strength of the vacuum gap and other factors, mainly depending on the rated voltage and the contact material.

Because the rated opening distance of the vacuum switch tube has a great impact on the insulation performance, when the rated opening distance increases from zero opening distance, its insulation level will also improve, but when the opening distance increases to a certain value, the opening distance has little impact on the insulation performance, if the further increase in the opening distance, will seriously affect the mechanical life of the switch tube.

Through the installation, operation and maintenance of the vacuum circuit breaker, the general selection range of the rated opening distance of the vacuum circuit breaker is: 6kV and below is generally 4 ~ 8mm, 10kV and below is generally 8 ~ 12mm, 35kV is generally 20 ~ 40mm.