| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to use a breaker without an earth leakage breaking function, by providing a pseudo open-phase circuit connected to a relay that is operated by a relay driving circuit for changing each contact on the basis of a signal from a seismic sensitive device. SOLUTION: A breaker 1 with an earthquake sensing function includes a seismic sensor 2 for detecting a vibration by an earthquake and generating a signal, a relay driving circuit 3 for switching a contact of a relay 4 on the basis of the signal, and a pseudo open-phase circuit 5 connected to the relay 4 that is driven by the relay driving circuit 3. The breaker 1 is connected to a conventional breaker 6. If an earthquake takes place, the vibration is detected using the seismic sensor 2 and a signal is generated. Then, the contact of the relay 4 is switched by the relay driving circuit 3 on the basis of the output signal. At the same time, the pseudo open-phase circuit 5 made up of voltage dividing resistors R1 and R2 generates a pseudo open-phase signal, which is detected through the breaker to break a single phase three-wire cable. As a result, the earth leakage breaking function is not required, and the breaker with only a neutral wire open-phase protective function can be used. |
