| 摘要 |
PURPOSE:To prevent a gas leak accident during a restoration period after power failure, by keeping a gas instrument stopped unless fixed instructions are issued, in a captioned system wherein every terminal controller connected with plural gas instruments is controlled by a central controller. CONSTITUTION:A power source switch 5 and an operation switch 6 are provided on a central controller 1, in a system controlling plural gas heaters 4 by the central controller 1 through a terminal controller 2 and a signal line 3 which are provided on the gas heaters 4 respectively. Then, on/off condition of the operation switch 6 is detected when the power pource switch 5 is turned on, when the operation switch is turned on a system is started as it is in an ordinary action mode when the switch 6 is in a turned off condition. On the other hand, when the operation switch 6 is in a turned on condition from the very beginning at this time, this is deemed as a restoration after power failure, and an alarm is generated. This alarm is kept on until the switch 6 is turned off, and then the system is started by turning the switch on. |
