OPERATION METHOD FOR VARIABLE SPEED PUMP AND VARIABLE SPEED PUMP DEVICE
Document Type and Number:
Japanese Patent JP3614665
PROBLEM TO BE SOLVED: To prevent service life variation of a pump by lessening a pressure variation during a number-increasing operation increasing the number of pumps operated and during a number-decreasing operation decreasing them and leveling an operation time of the pump.
SOLUTION: When a pressure detected by a pressure sensor provided on a water feed piping becomes less than a starting pressure, CPU 11 activates a pump and inverter-controls the advance pump such that a discharge pressure becomes a target pressure. In the case where the discharge pressure does not arrive at the target pressure even by the inverter-control, a number-increasing operation increasing the number of pumps is carried out. After the number of revolutions of pumps is increased until a speed arrives at a maximum speed at a variation speed of a predetermined value or less, the pump is operated at the maximum speed. In the case where a demand of water is decreased, a number-decreasing operation decreasing the number of pumps operated is carried out. The advance pump moving at a variable speed is stopped and a pump the most previously activated of the later pumps is made to a new advance pump. Thereby, the advance pump is not driven for a long time and an operation time of the pump can be leveled.
November 12, 2004
June 29, 1998
KAWAMOTO PUMP MFG CO LTD
F04D15/00; F04B49/06; (IPC1-7): F04B49/06; F04D15/00