| 摘要 |
PURPOSE:To permit to control a plurality of water discharging pumps so as to be capable of operating under rated operating condition or stopping in accordance with necessity by a method wherein starting or stopping of the operation of one set of the pump is effected in case a water level changing rate, obtained by detecting the water level, is higher than a predetermined value and subsequently starting or stopping of the pump, provided in parallel to the afore- mentioned pump, is effected. CONSTITUTION:The water level changing rate, obtained by detecting the water level of a pump well 3 by a water level meter 4 and inputting the detected water level into a changing rate detecting circuit 7, is inputted into a changing rate determining circuit 10 and a conventional type number of operating set control circuit 5 or the same circuit 5' of present invention is used separately in accordance with the magnitude of the changing rate determined by the circuit 10. The magnitude of the water level changing rate is discriminated in a step 21 and in case the discrimination is NO or the water level changing rate is lower than the predetermined value, the step is advanced to the step 22 to start the water discharging pumps sequentially by the conventional type control circuit 5 after waiting for the opening and closing time of the discharging valve and an effect determining time. In case it is YES or the water level changing rate is higher than the predetermined value, the step is advanced to the step 23 to permit to start the water discharging pumps sequentially and immediately by the control circuit 5' of the present invention without waiting for the opening and closing time of the discharging valve and the effect determining time. |
