Reasons for operational failures in multi-stage centrifugal pumps
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This post was last edited by shglpv on 2011-7-7 at 13:39. After a GDL vertical multi-stage centrifugal pump was delivered to the customer and installed, the motor burned out during use; even after replacing the motor, the problem persisted. The pump was capable of achieving a head of 120 meters, but it only managed to achieve 100 meters there. What other possible causes could there be besides this one? How can I install it to achieve a head of nearly 120 meters? Help needed
Check if the outlet pipe valve is open too wide. It’s likely that the excessive flow rate causes an overcurrent, which is why the head pressure cannot be increased. You might have chosen a pump that is too large.
What’s the problem? The gods can help you. To ask questions here, you need to explain the background clearly
For GDL vertical multi-stage centrifugal pumps, if the rated head is 120 meters but the pump only achieves a head of 100 meters, this is still within the rated range. The fact that the pump’s outlet head does not reach the rated 120 meters may be due to the characteristics of the piping system. However, if the motor burns out after the pump is installed, and the problem persists even after replacing the motor, then it is possible that there is an issue with the pump itself or with the electrical wiring. For example, in the case of star-delta starting, the pump may not be able to switch to delta operation after starting up.
The question isn’t clear enough to make a judgment. If the head does not reach the design value, it does not necessarily indicate an installation issue; it is necessary to carefully examine factors such as the inlet and outlet flow patterns, medium temperature, pressure, and so on. There are many reasons for motor burns: mechanical components, electrical components, and so on. No images, no details about the scene – not even the gods can help you.
You can try following these steps: close the outlet valve completely, start the pump, and check for any abnormal noises. If there are such noises, it indicates a mechanical fault. If not, then slowly open the valve and adjust the pressure to 1.2 MPa. If everything operates normally, it means that the motor was damaged due to insufficient head pressure
Check whether the motor is compatible with the pump； Check whether the outlet valve matches the diameter of the pump’s outlet pipe; if the valve is larger than the outlet pipe diameter, it will cause overload ； If they are consistent, gradually adjust the outlet valve and observe the changes in current ；