Gas-insulated vacuum circuit breaker
Sealed chamber for monitoring pressure 23 is provided on sealed tank 37 . Sealed tank 37 is filled with insulating gas. And, a connection using insulated pipe 19 is provided between medium-pressure space 18 that makes a medium pressure and sealed chamber for monitoring pressure 23 . In sealed chamber for monitoring pressure 23 , a pressure monitoring and controlling means is provided for monitoring the internal pressure thereof to activate the pressure-release control in response to the situation where the monitored internal pressure has reached the predetermined setting value. The pressure monitoring and controlling means includes solenoid valve 28 that is capable of opening sealed chamber for monitoring pressure 23 to the atmosphere, pressure detector 26 that detects the internal pressure, and pressure monitor 27 , which activates solenoid valve 28 for pressure-release when pressure detector 26 detects that the internal pressure has reached the predetermined abnormal pressure value.
1. A gas-insulated vacuum circuit breaker comprising:
a sealed tank being filled with insulating gas;
a vacuum valve being arranged in the sealed tank, the vacuum valve including a movable electrode, a fixed electrode, a bellows, and a vacuum tank, and opening the movable electrode from the fixed electrode maintaining vacuum condition within the bellows;
a medium-pressure space being arranged in the sealed tank, the medium-pressure space applying pressure on one surface of the bellows that is the other surface of the bellows on which vacuum pressure being applied, the medium-pressure space being maintained to an intermediate pressure condition between the pressure of the insulating gas filled in the sealed tank and the vacuum pressure;
a sealed chamber for monitoring pressure being provided on the sealed tank to monitor the gas pressure;
an insulated pipe being installed between the sealed chamber for monitoring pressure and the medium-pressure space connecting therebetween; and
a pressure monitoring and controlling means being installed in the sealed chamber for monitoring pressure,
the pressure monitoring and controlling means monitoring the internal pressure thereof and controlling the internal pressure according to a predetermined setting value.
2. The gas-insulated vacuum circuit breaker according to claim 1 , wherein the pressure monitoring and controlling means includes a solenoid valve, a pressure detector and a pressure monitor, the solenoid valve opening the sealed chamber for monitoring pressure to the atmosphere, the pressure detector detecting the internal pressure of the sealed chamber for monitoring pressure, the pressure monitor opening the solenoid valve when the pressure detected by the pressure detector reaches a predetermined abnormal pressure value.