Vacuum interrupter, also known as the vacuum switch tube, is the core component of the medium-high voltage power switch. It is mainly applied to the power transmission and distribution control system, and it is also applied to the distribution systems of metallurgy, mine, petroleum, chemical, railway, broadcasting, communication and industrial high frequency heating.Vacuum interrupter has the characteristics of energy saving, material saving, fire prevention, explosion-proof, small volume, long life, low maintenance cost, reliable operation and no pollution. The vacuum interrupter is divided into the use of the interrupter and the load switch. The interrupter of the circuit breaker is mainly used in the substation and the power grid facilities in the electric power department.
Strictly control the closing and opening speed of vacuum circuit breaker.For the vacuum circuit breaker with a certain structure, the manufacturer has specified the best closing speed. When the closing speed of vacuum circuit breaker is too low, the wear of contact will increase due to the extension of pre breakdown time; When the vacuum circuit breaker is disconnected, the arcing time is short, and its maximum arcing time does not exceed 1.5 power frequency half wave. It is required that when the current crosses zero for the first time, the arc extinguishing chamber should have sufficient insulation strength. Generally, it is expected that the stroke of the contact in the power frequency half wave will reach 50% – 80% of the full stroke during circuit breaking. Therefore, the opening speed of the circuit breaker should be strictly controlled. As the arc extinguishing chamber of vacuum circuit breaker generally adopts brazing process, its mechanical strength is not high, and its vibration resistance is poor. Too high closing speed of circuit breaker will cause greater vibration, and will also have greater impact on bellows, reducing the service life of bellows. Therefore, the closing speed of vacuum circuit breaker is usually set as 0.6 ~ 2m / s.