Pump startup issue
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To start the water pump, should the outlet valve be opened first or the power supply? Why? To shut down the water pump, should the outlet valve be closed or the power supply turned off? Why
When starting a centrifugal pump, the inlet valve of the pump should be opened first to allow liquid to enter the pump, while the outlet valve should remain closed – or at least slightly open – before starting the pump； When stopping the pump, first close the pump’s outlet valve, then stop the pump itself. The pump’s inlet valve can be closed or left open depending on requirements; leaving it open can simplify the procedure when starting the pump again.
To start the pump, first open the inlet valve of the pump to allow the liquid to fill the pump chamber. The outlet valve is usually closed, but it can also be opened a little. Then press the start button for the pump. In this way, the starting current of the pump is minimized, protecting the electrical components of the pump. When starting the pump, if the outlet valve is fully open, the current drawn at the moment the pump starts is very high, usually exceeding twice the rated current, which can damage circuit breakers, AC contactors, motor windings, and other components.
For both starting and shutting down, the power supply is operated first, followed by the outlet valve, due to the presence of an outlet check valve.
Hehe, have you heard of the term \"water hammer\"?
For both starting and shutting down, the power supply is operated first, followed by the outlet valve; this is because of the outlet check valve. Rough handling can result in a starting current that is 7–9 times the rated current