The outlet pressure of the centrifugal pump has reached the required head, but the current is not 80% of the rated current
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During the individual testing of the centrifugal pump, the outlet pressure of the pump already reached the pressure corresponding to its head, yet the motor current did not reach 80% of the rated current. What could be the reason for this? How do I adjust it?
What about traffic? This is related to the size of the optional motor.
Motors are generally specified with a margin, operating normally below their rated capacity
The motor current does not reach 80% of the rated current with any margin
First, check the flow rate to see if it reaches the rated value； Secondly, try using a different flow meter; it might be an error on the flow clamp ； Also, according to API 610, the motor selected is generally 10%~125% larger in power than the shaft input power of the pump ； Furthermore, the actual efficiency of the pump may be higher than the efficiency guaranteed at the time of bidding ； Finally, check the inlet pressure to see if it is a bit higher than the design value Lastly, is the density of the medium used during your single-unit testing different from that in the actual operational conditions? There are many possibilities; it’s best to compare them with the data from the factory tests.
The motor size is probably too large. This phenomenon of big horses pulling small carts is quite common
If the performance curve of the pump is relatively flat, the outlet pressure changes little as the flow rate changes. At the same pressure, flow rate and power are directly related. Check whether the flow rate meets the design standards. Additionally, when selecting a pump, to prevent the motor from experiencing overcurrent, a safety factor of generally 1–1.25 times is applied to the motor capacity.
The outlet valve isn’t open, is it? Try opening the outlet valve wider.