| 摘要 |
PURPOSE:To reduce the number of attendance of unnecessary maintenance service personnel at time of power failure in a power source for a terminal unit by installing such a means as selecting the power source of the terminal unit to an elevator power source from a building power source for connection when the elevator power source is not yet cut off, whereas the building power source is broken down. CONSTITUTION:An elevator power source V is connected to a rectifier 3 via two normally closed contacts 1b1, 1b2 of a relay 1, while this rectifier 3 is fed out of a building power source U when the relay is energized, and when this relay 1 is unenergized, it is fed out of an elevator power source V. When the building power source U is cut off due to power failure, the relay 11 is unenergized, and both contacts 1a1, 1a2 are opened while the contacts 1b1, 1b2 are closed, and the rectifier 3 is connected to the elevator power source V, so that DC power is fed to the terminal unit 4 via both contacts 2a1, 2a2. At this time, contacts 1b5, 2a3 are also closed so that this condition is counted by a counter 7. Since the elevator power source V is energized with current, an elevator power source trouble signal is not emitted. |
