PURPOSE: To prevent the timing of start of water pump-up operation from being delayed, by standby-operating a pump driving prime-mover in a clutch turn-off condition until the water level of a pump-up water well comes to a water pump-up start level, and by fulling water in a pump through the operation of a water level raising means.
CONSTITUTION: A pump driving prime-mover 14 is started and is standby-operated in a clutch 13 turn-off condition until the water level of a pump-up water well 1 comes to a water pump-up start level HWL from a lowest level LWL, and a vacuum pump 20 in a water level raising means 11 is started so that the prime-mover 14 performs a full speed standby operation in such a condition that the water level is raised up to a full water level HWL1 within the pump. Further, when the water level of the pump-up water level comes to the water pump-up start level, the clutch 13 is turned on so that a pump main shaft 12 and an impeller 3 are rotated so as to start discharging. With this arrangement, even in an emergency operation in which a large volume of water abruptly flows into the pump-up water well 1, it is possible to prevent the timing of start of water pump-up operation, thereby it is possible to prevent occurrence of a flood caused by abnormal rise of the water level of the pump-up water well 1.
SUZUKI NOBUHIRO
YONEMURA SHOICHI
FURUKAWA HIROHIKO
KONISHI MASAHIDE
JPH0279101A | 1990-03-19 | |||
JPS5028642A | 1975-03-24 | |||
JP63121797B |