... adjusting.. Fixed mode of 1 drive controlling n pumps(2<n<8): 1 drive controls n pumps. One pump controlled ... voltage.Operation FunctionFrequency SettingPotentiometer or external analog signal; keypad (terminal) keys, external control logic and auto-circulating ... -load, over-heat, motor detection fault, external equipment fault, external disturbance, water lack protection, pressure protection, line ...