Seek help regarding pump overcurrent
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We have a pump of model IHE80-50-250 that was originally used for acid removal and is now being used to handle wastewater. The motor trips due to overcurrent; we replaced the motor as well as the pump bearings, but the problem of overcurrent persists. The pump rotates smoothly when turned by hand. Please advise us – any details regarding possible causes of overcurrent would be greatly appreciated. Thank you!
1. Check the power distribution issues in the electrical cabinet, as well as any problems with its components. 2. Stop the pump from operating at its outlet and monitor the current level
The outlet valve isn’t open yet, and the idle speed is already too high
1. The power of the motor used with the centrifugal pump is too low: The solution is to adjust the configuration and replace the motor. 2. The pump’s rotation speed is too high: The solution is to reduce the pump’s rotation speed. 3. Bent pump shaft, worn or damaged bearings: Solution – straighten the pump shaft and repair or replace the bearings. 4. The packing is compressed too tightly: Solution – loosen the packing gland. 5. The actual operating head is much lower than the pump’s head, resulting in an excessive flow rate: The solution is to reduce the outlet valve to control the water pump’s flow rate. 6. The couplings are not aligned or the gap between them is too small: The solution is to correct the alignment or adjust the gap between the couplings. 7. Prolonged shutdown times lead to thermal expansion, increasing friction in the seal ring: The solution is to follow the standard operating procedures and stop the machine immediately for inspection in case of any faults. 8. It’s possible that something has gotten stuck inside; first, check whether there is any blockage in the inlet and outlet pipes, and then check if something is blocked inside the pump as well. 9. The motor gets damp due to being submerged in water: Solution – dry the damp motor.
The coupling gap is too small and it has not been aligned properly; as a result, the coupling experiences strain during operation, leading to excessive current consumption. After changing the medium in the pump, does the actual head decrease, resulting in an excessive flow rate and high current? In such cases, it is necessary to replace the impeller.
It is recommended to check the wiring in this case; since the outlet valves are not opened, overcurrent occurs during idle operation. If the equipment can be rotated smoothly when stopped, it is likely that there is no major issue with the equipment itself.
Resolved: The electrician replaced the wrong motor; a four-pole motor was replaced with a two-pole motor