OPERATION CONTROLLING METHOD AND DEVICE FOR MIXED-FLOW OR AXIAL-FLOW PUMP TAKING SUBMERGED MOTOR AS MOTOR

摘要

PROBLEM TO BE SOLVED: To provide an operation controlling method and device for a mixed- flow or axial-flow pump taking a submerged motor as a motor, capable of making full use of motor output by operating at an increased a peed pump in the low head range in which the motor has sufficient horsepower and capable of realizing prevention of overload by operating the pump at reduced speed in the high head range. SOLUTION: An inverter 4 is interposed in an electric circuit 5 extending from a submerged motor 2 to a facility power source 3 so that the speed of a pump 1 may be increased when the delivery head lowers and so that the speed of the pump 1 may be reduced when the delivery head rises. A controller 6 composed of a measuring and controlling part 7 for detecting a power value and a current value of the submerged motor 2 and outputting a control signal proportionate to the detected signal and a revolution control part 8 for outputting a revolution command proportionate to an output signal from the measuring and controlling part 7 to the inverter 4 is provided, and frequency power source proportionate to the revolution command is supplied from the inverter 4 to the submerged motor 2.