PURPOSE: To shorten inspection time and to realize labor-saving inspection by providing an electrode for inspection to a case body which contains a vacuum breaker and deciding on whether its degree of vacuum is normal or not, and thus eliminating the need to disconnect the breaker from a system and switch it to a spare circuit.
CONSTITUTION: When the vacuum breaker 10 deteriorates in degree of vacuum, glow discharge is caused between electrodes 12 and 14, and an intermediate shield 18, the voltage of the shield 18 rises and the earth potential of an electrode 24 for detection also rises. For this purpose, a cover 30 is detached in inspection and a detection terminal 32 is connected to the electrode 24 for detection; and the voltage of the electrode 24 is measured by a high resistance voltmeter 34 to decide on whether the degree of vacuum is normal or not.
SAKAKI MASAYUKI
FUKUSHIMA TOMIO
TANIGAKI SHIYUUZOU
| JPS5085371A | 1975-07-09 | |||
| JPS5315569A | 1978-02-13 | |||
| JPS56133640A | 1981-10-19 |