| 摘要 |
PROBLEM TO BE SOLVED: To adjust a delivery flow smoothly to increase or decrease it by properly switching over a constant frequency power and an inverter device to a plurality of pump motors without using a starter device that must be reduced in size. SOLUTION: A first group of switch means SW1-1, SW1-2, SW1-3, and SW1-4 are provided between the output end of an inverter device VF and motors M1 to M4 connected to pumps P1 to P4, respectively, and a second group of switch means SW2-1, SW2-2, SW2-3, and SW2-4 are provided between a constant frequency power 10 and the motors M1 to M4. A flow detector means 12 to detect a delivery flow and a control means 14 are installed and, based on a signal detected according to the delivery flow, the control means 14 adjusts the output frequency of the inverter device VF and controls to open or close the first and second groups of switch means SW1-1 to SW2-4. |
