Vacuum circuit breaker works with other circuit breakers different compared to the arc medium fills the vacuum does not exist conductive medium, quickly extinguish the arc vacuum high voltage circuit breaker factory outlets, so little movement spacing between the contacts of the circuit breaker . The circuit breaker is generally used for relatively low voltage auxiliary power configuration! With the rapid development of power systems, 10KV vacuum circuit breakers have been produced and used in large quantities in China. For maintenance personnel, to improve understanding of the vacuum circuit breaker, vacuum circuit breakers to strengthen the maintenance of factory outlets, making it safe to run, it has become a pressing issue. In this paper, ZW27 - 12 as an example, a brief description of the principles and maintenance of vacuum circuit breakers. I vacuum arc and gas arcing very different circuit breaker, the phenomenon of free gas arc is not the main factor, the vacuum arc discharge is evaporated in the contact electrode formed in the metal vapor. At the same time, the size of the different breaking current arc performance characteristics are also different. We generally divide it into small current vacuum arc and large current vacuum arc. Factory direct high-voltage vacuum circuit breaker, breaker Lanzhou, Xi'an by the Xi'an high Huayi power plant. Xian Huayi Electric Power Equipment Factory (www.xahy.com) strong, credible, in the Xi'an high-voltage circuit breakers and other industries has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Huayi electricity into the brilliant and you work for a better future!