VACUUM RATE MONITOR FOR VACUUM CIRCUIT BREAKER

摘要

An abnormally high vacuum pressure of a vacuum interrupter is detected from outside the interrupter. The interrupter detects electromagnetic wave signals which are generated by an electric discharge derived in response to a voltage difference and dependent upon Paschen's law. It is possible to detect poor vacuum presure on the basis of the electric discharge existing between the fixed and movable contact rods including two contacts and the main shield, as well as when the two contacts are open. The monitor comprises a rod or loop antenna fixedly or movably disposed near a conductive material or connected to the interrupter and a detection section including a band pass filter.