Centrifugal pump anomaly

[roricaja23]

I have a system that uses a 480V 3ph motor driving a submerged centrifugal pump. The system is flushing at the moment and the discharge goes to 8 different bearings. The pump when deadheaded is right on with the pump curve. When all of the valves are open allowing maximum flow, the pump also matches the pump curve. As the valves are closed one by one, there for restricting the flow, the pump discharge pressure increases as expected. The anomaly here is that the amp draw on the motor increases as well. I am dealing with bearings at different elevations but the kicker is that the last valves to be closed at those at the highest elevation which should even more so decrease the flow and decrease the amp draw on the motor. Any ideas?

 

[BigInch]

Move along folks. Nothing here to see.

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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

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