Analysis of the reasons for centrifugal pump overload
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When the centrifugal pump is started with the outlet valve closed, the motor shuts down due to high current. This pump has been in use for a long time; it’s not a new pump. Its efficiency is somewhat low, at only 20%, with a head of 123 meters. The motor functions properly when tested individually, and no abnormalities were found upon inspecting the pump itself. Has anyone encountered this situation? Help me analyze what’s possible
There were no issues during previous runs, so why is there a problem now? Was it repaired before the problem occurred? Have there been any changes in the process medium parameters?
It was fine before; the current was a bit high, but it still worked. It was in standby mode previously, and a problem was detected during a routine pump swap. The process parameters should remain largely unchanged; the other unit can operate
This post was last edited by wangshunyu on 2018-1-18 at 16:31. Could it be that issues such as damaged bearings or uneven balance discs are causing the motor to require more power to operate?
Before operation, the pump needs to be turned over, the lubricating oil checked, and electrical insulation inspected, among other checks. The motor is overloaded; perhaps the bearings are damaged ； The impeller fastening bolt has fallen off ； The pump filter is damaged, foreign objects have entered the pump, and so on. It might be a electrical fault.
What is the flow rate of this pump? In such cases, the side-channel pump should be started by opening its valve.
I encountered a similar problem: I had a two-stage pump that kept tripping due to overcurrent. I tried replacing the motor, and it was confirmed that the motor wasn’t the issue; there were no problems with the clearance at the pump inlet or with the bearings. Later, it was discovered that the intermediate sleeve had come loose and welded itself apart. After fixing it, the pump stopped tripping, but the current level remained high, though it was no longer above the acceptable limit. Who knows how to solve it? Seeking help too.
The current is high after maintenance; it may be necessary to check whether the impeller, drive shaft, and bearings are damaged, although the damage is not very severe.
Could the poster please tell us whether this pump is a single-suspension pump or a multi-stage pump? ~~~123 meters~~ It seems level 3, level 2, or even just a single level will work~~~
Check if there is any issue with the electrical current limiting