| 摘要 |
PURPOSE:To attain efficient maintenance work by automatically detecting the fault of either unit in alternate operation or stand-by operation immediately after its occurrence and then by putting the system into break-side operation. CONSTITUTION:By switching signals 22 and 23 from automatic selector circuit 12 by automatic alternating operation input signal 20 and stand-by signal 21, gate circuits 13 and 14 instructs two water supply and exhaust pumps, for example, to start and stop. Then, when an overcurrent is drawn through the motor to input periodical detection signal 28, or when time-limit detection circuit 16 supplied with operation end signal 33, delayed masking signals 31 and 32 and time pulse signal 29 generates out-of-time fault signal 30 since the pressure does not reach a prescribed value after constant time passes since the pump started, fault signal generating circuit 15 receiving either or both signals 28 and 30 outputs locking signal 26 to the fault side and the operation is switched to the break side by fault switching signal 25 while the alternating operation is stopped by operation mask signal 24. |
