The transient in switching of the capacitor bank has been analyzed in this paper

to reach the double recovery voltage at the breakpoint

and the operating conditions of 20 times or higher impulse current.An average trajectory graph-analytic method was used at the processing movement of the contactors

which setting in 10 kV vacuum circuit breaker

to reach a defect of the "slowopening state" and "slow-closing state"

which leads a possibility of restrike during opening and damage during closing.An effects of restrike was the damage of capacitor

without the breaker.Analysis shows that the accident of both capacitor and breaker was attributable to a structural deficiency

an unfitting of capacitor and breaker.Analysis appealed for a cooperating of the manufacturer and the operator

to make the vacuum technique was used by electric power system.