| 摘要 |
PURPOSE:To eliminate the variance of the number of running times and to prolong the life of each device by storing the numbers of starting and stopping times of each device during the prescribed set period and selecting the operational sequence of each device so as to average said numbers of each device. CONSTITUTION:When a water level is raised in the order of numbers 1-5 and dropped in the order of numbers 6-8, these orders are assumed to average the numbers of starting and stopping times of each pump. Namely, when the pumps P1-P3 are sequentially operated at water levels 2-4 and go to the water level where the pumps are stopped, first the pump P1 is stopped at the water level 6. Next the pump P1 is started and then three pumps are operated to stop the pump P2. Furthermore the pump P2 is started and then three pumps are operated. Then the pump P3 is started to stop the pump P1, and then the pump P3 and the pump P1 are sequentially started. In such a way the start and stop of the pump are cyclically averaged. |
