| 摘要 |
PROBLEM TO BE SOLVED: To prevent a fire trouble, by providing a holding means for a tripping command of a breaker and holding the tripping command fed from a seismic sensor until the power is cut by the breaker. SOLUTION: A seismic sensor 3 is set at seismic intensity of about five, and the seismic sensor 3 and a memory 4 are operated by a back-up power supply 6 when an earthquake with seismic intensity of five or above takes place. The seismic sensor 3 detects an earthquake to generate an output, which is held in the memory 4. In this case, the data is held continuously in a stand-by state. When the power failure is restored and the power transmission is carried out again, a trapping coil 2 is operated by commercial power applied through a contact 501. Then, a contact open/close mechanism 1 is tripped to open a main circuit contact, and the power is stopped just at the re-start of the power transmission. Since the output of earthquake detection can be held until the power transmission after the restoration of the power failure, the breaker is opened again just at the power transmission and a fire trouble can be prevented. |
