Selection of water pump power
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For a centrifugal water pump, the required power supply voltage is 380V, the head is 40m, the medium is water, and the flow rate is 10 cubic meters per hour. I would like to know how to calculate the power required for this pump. I calculated that an engine of around 1.5 KW would be sufficient for rounding purposes, but the design institute determined that 5.5 KW is needed – the difference is quite large.
1.5-2.2KW is about right. The design institute must have included a margin.
Pump efficiency is related to the selection of the pump; it is recommended to consult the pump manufacturer.
The efficiency of the pump has a significant impact on power selection
The efficiency of a clean water pump with a flow rate of Q=10 m3/h is approximately 65%. Based on this 65% efficiency, the motor power required should be 3 KW. 5.5KW is indeed too high:a
Shaft power: QHρ/(102*3.6*η). Shaft power in kW = motor power. With a flow rate of 10 cubic meters per hour, a head of 40 meters, a water density of 1, and an efficiency of 65%, K is set at 1.25. The motor power is 2.1 kW; therefore, 2.2 kW is used