| 摘要 |
PURPOSE:To detect other troubles while a bell is turned off by connecting the contact point of a trouble relay to an electrical key for turning off, and an alarming relay, and connecting one contact point of the alarming relay to the contact point of the trouble relay, and other contact points to the ground and the bell, respectively. CONSTITUTION:One of trouble relays 1a-1n corresponds to a trouble of one of switchboards 5a-5n, for example 5a. When the 1a operates, a contact 1ab is closed to operate an alarming relay 8, and close a contact point 8x. At the same time of self-holding, a contact point 8y is closed, and a bell 6 ring. At the same time, a contact point 8a is closed to operate the trouble relay 1a. The relay 1a holds itself until the trouble recovery of the switchboard 5a by the contact point 1ab. A maintainer cuts an electronical key 9, stops the bell 6, and executes the maintenance. Thereafter, when other troubles generate in the switchboard 5n, a contact 1nb is closed by the operation of the relay 1n, the contact point 8y is closed by the relay 8, and the bell 6 is driven. Thus, a new trouble which generates during the maintenance is also alarmed. |
