Board: General pump problems
Topic: High current-problem

Article from Radoslav at Jun 16 2009, k:ih

High current-problem Hello to All, I have a problem with submersible pump unit with high current at one pump. Actually there is two pumps in the system. One operating and one stand by. Pump No. 1 work without any problem and satisfies capacity requirements. Pump No. 2 also satisfies requirement capacity but current is to high and after 30 min SCADA turn it off. Both pumps are working in optimum operating range on Q-H and Q-P curves. When I changed position of the pumps without changing connection of power supply and signal cables the problem was still exist but now on same place with the other pump, Did anyone have similar problem??

Answer from Bhalchandra Padwal at Sep 16 2009, k:ih

Check up list Its obvious that both Pump Model and Motor rating are same. a) Check if they Pump Model and Motor rating are same? b) Pump B is has worn out from inner side, so clearance have increase, slippage is more, efficiency decrease. Thus Pump B draws more current. This is hypothetical because your speed is constant ( if you are using variable VFD on pump then this is possible ) c) Pump B is drawing more power, may be there is Hysteresis loss in motor (i.e. copper and iron losses ) due to which your motor efficiency has decrease. So motor of Pump B is drawing more current. Change the motor. d) Do you know that motors are available in different type in market. ( like SPDF, TEFC,FLP, Increase in Safety, Eff 1, Eff 2 etc ) check if both motors are of same type. Hopefully your problem is sorted out. Please let us know, if there is any requirement in your plant.