High Voltage Vacuum Switch Tube

Vacuum switch tube ,is also named vacuum interrupter. With the advantages of small volume,  strong breaking capacity, maintenance free contact terminal,It is widely applied in coal enterprises, power sector, chemical industry, metallurgical industry, petroleum industry.

WORKING PRINCIPLE

Vacuum interrupter(VI) is a kind of electric vacuum device, which uses high vacuum insulating interrupter and a pair of contacts sealed in vacuum to realize the on-off function of power circuit. When a certain value of current is disconnected, at the moment of separation, the current shrinks to the point where the contact is just separated, and the resistance between electrodes increases sharply and the temperature increases rapidly, until the evaporation of electrode metal occurs. At the same time, a very high electric field strength is formed, which leads to a very strong emission and gap breakdown, resulting in a vacuum arc. When the power frequency current is close to zero, it is also the increase of the contact opening distance. The plasma of vacuum arc quickly spreads around. After the arc current passes zero, the medium in the contact gap quickly changes from the conductor to the insulator, so the current is broken.

Due to the special structure of the contact, the contact gap will produce a proper longitudinal magnetic field during the arcing. This magnetic field can make the arc evenly distributed on the contact surface to maintain a low arc voltage, so that the vacuum interrupter has the characteristics of high dielectric strength recovery speed, small arc energy and small corrosion rate.

TECHNICAL DATA