| 摘要 |
PURPOSE:To smoothly restart a pump by opening the first valve when a predetermined time elapses after the pump detects idle running, opening the second valve to feed water via a priming means, then closing the second and first valves in sequence. CONSTITUTION:When the water level is lowered and a pump 11 reaches an idle running condition, an idle running preventing pulse which opens an idle running preventive switch via an idle running detector 24 is generated from a control circuit 25, and the operation of the pump 11 is stopped. When a predetermined time elapses via a timer circuit 26, a switch 27 for opening a valve 13 provided at a priming port 12 is closed, then a switch for opening a valve 17 is closed, and water is fed to the pump 11 from a tank 14 via a water fed pipe 18. After a sufficient time to feed water elapses, the switch 28 is opened, the valve 17 is closed, then the valve 13 is closed. Under this condition, a switch 22 is closed, and the pump 11 can be smoothly restarted automatically.
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