| 摘要 |
PURPOSE:To control the number of operated pumps stably, by calculating and comparing operation periods in consideration of operation frequencies of all pumps and determining a pump operation order so that operation periods and operation frequencies of all pumps are uniform. CONSTITUTION:Operation period integral values H1, H2...H5 of water supply pumps P1, P2...P5 are obtained, and a pump having a minimum operation period integral value is selected and is defined as the pump which is first operated. Next, if an opreration number signal 9 indicates that an already operated pump exists and the operation signal of an additional pump is inputted to an operation order setting circuit 10, operation period integral values of stopped pumps are read. These read operation period integral values are compared to select a pump having a minimum operation period integral value. A timer value of the operation period of the selected pump is read, and the timer value is added for every pump, and a pump having a maximum value is selected. A stop signal is sent to a controller 12 for the selected pump to reset it at a set time. This operation is repeated to continue the operation until all water supply pumps are stopped. |
