Motor power for starting the pump at full flow rate
Thread Content
For centrifugal pumps, one in operation and one as a backup, and since there is an interlock system that enables the backup pump to start automatically at low pressure, the motor required must be capable of driving the pump at its full flow rate. Is that correct? How should the motor be selected? Normally, we choose the pump based on the shaft power multiplied by a safety factor.
Look at the curve; as long as the total flow does not exceed the rated power, a standard motor will suffice
Start with reduced voltage; it’s better to leave some power headroom
The situation you mentioned rarely occurs. Under normal circumstances, there is an overload in current at startup along with a delay; the power isn’t cut off as soon as the current exceeds the limit, but rather after 2 seconds if it remains above that level.
Select based on the maximum power corresponding to the end of the pump curve