| 摘要 |
PURPOSE:To compensate shortage of water supply under acceleration of variable speed pump, when operating both variable speed pump and constant speed pump, by stopping the constant speed pump upon reaching to predetermined pressure level. CONSTITUTION:Upon droppage of water supply pressure below setting level, contactors MC0, MC1, MC2 are turned on by means of pump start command systems Pr1, Pr2 to operate the variable speed pump 1 and constant speed pump 2 simultaneously thus to function a timer T1. Upon elapse of predetermined time, power supply to the contactor MC2 is interrupted to stop the constant speed pump 2. Upon further droppage of water supply pressure through operation of variable speed pump 1, the variable speed pump 2 is turned on as conventional operation control. |
