Overcurrent issue in the motor of a single-stage, single-suction centrifugal pump
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The IS-100-65-250 is a single-stage, single-suction cantilever pump with a flow rate of 100 m3/h and a head of 85 m. It is equipped with a 37 KW motor, and the fluid handled is clean water. Ideally, the shaft power of the pump should be slightly over 30 KW, so overflow should not occur; however, the motor keeps experiencing overflow issues. When the valve is adjusted to ensure operation at the rated flow rate, the motor’s temperature rises above 90 degrees after a few hours, forcing it to stop operating ； Two motors have been replaced, and the motor bearings have also been changed. The pump is new, and its vibration levels are not high after it starts operating; I’m not sure what the reason for this is. The motor bearings use NSK CM clearance bearings; would it be better to switch to bearings with C3 clearance?
Is the motor current too high? Is the pump bearing hot? On the performance curve from the pump’s factory tests, what is the actual flow rate of the pump during operation?
Will the motor overheat even if the current is reduced and the valve is set to the rated current?； There is no performance curve for factory testing; the pump operates under load at a flow rate of 70 m3/h.
We will replace it with a pump for you free of charge. Save on electricity bills for a year.
Our pumps come with a three-year warranty. Ensure no overcurrent.
Consider whether it might be a problem with the impeller
It is recommended to first disassemble the coupling and test the motor separately to determine if there are any issues with the motor itself. If it works fine, then it’s likely that the problem lies with the pump. Based on what the original poster described, it’s very probable that the power of the motor used is insufficient; the main reason for this could be the low efficiency of the pump itself. Using a pump with higher efficiency should resolve this issue: lol. Solution: Replace the pump or motor, which will resolve the problem fundamentally. Alternatively, if the production process permits, the impeller can be cut off – this is the fastest way to solve the issue. I hope this helps.
Will you modify the 37KW pump as well?
15-kilowatt ones can also be modified. It mainly depends on the energy-saving benefits. The price is reasonable; those at 7.5 can also be adjusted
Your 37 is likely up to 40 kilowatts now. After the modification, it’s 20 kilowatts, which means 20 kWh of electricity is saved per hour. Assuming 8,000 hours of operation per year, that amounts to 160,000 kWh of electricity saved, resulting in annual savings of around 100,000 yuan in electricity costs. Collect for one year; it can definitely be changed
I think there’s nothing wrong with the pump itself; the main issue is that the actual head is low, resulting in operation at high flow rates