What’s wrong with my pump?
Thread Content
The lift pumps located beneath the sewage treatment plant are submersible sewage pumps (model 65WQP30-15-3), with a flow rate of 30 cubic meters per hour, a head of 15 meters, and a power output of 3 KW. It features automatic coupling installation: the pump is lowered to the bottom of the sewage tank along guide rails and automatically connected to the discharge pipeline, suitable for sewage with suspended solids below 400 mg/l. Recently, the pump has been shutting down frequently; the current measured was much higher than the rated current. It was confirmed to be a overcurrent trip, but no blockage was found upon inspection. And the pump flow rate is too low. The pump outlet is connected to the pipeline in a non-sealed manner. Let’s see where the problem might lie It is also considered to install a pipeline pump on the outlet pipe above this tank, at a distance of about 10.5 meters from the bottom of the tank, with a required flow rate of 50 cubic meters per hour. Help choose the style.
First, calculate the motor power (there should be no problem). There is no need to install a pipeline pump (it’s simply a waste of investment and it increases the operating costs of the equipment); unless you have chosen a low head for your submersible pump, in which case it’s sufficient to choose one with a higher head (calculate the head required for the piping system). Even though it doesn’t clog, you can also install a basket filter in front of the pump.
Are you sure about the criteria you used for that selection? 313239218: If you’re interested, add me on QQ and we can chat for a while
The power output exceeded the rated value; replace with a larger pump.
Contact the pump manufacturer directly to request their technical support; it seems there is a fault with the pump. Check whether there is any blockage in the impeller’s flow channels. If it’s a new pump, it might be due to manufacturing defects, and this has nothing to do with the selection of the pump. If you need to purchase a pipeline pump, you can contact me at QQ248410156.
The pump is installed near the bottom of the tank; as a result, the suspended solids concentration at the bottom may be relatively high, which requires a higher power level than actual needs. Additionally, check the issues with the motor as well; the phase deviation protection setting for the motor might be too low (that could be the cause; I’m not sure how to describe it exactly – you can ask someone from the power supply department). This could also lead to frequent tripping. I believe there is no need to replace the large pump, the large motor, or the pipeline pump; instead, it is necessary to carefully examine the deviations in actual operation.