Pump Amp Problems
Pump Amp Problems
(OP)
I am having serious problems with a centrifugal pump, with VFD drive. The motor is spec. is 150 HP and 1800 RPM.
The VFD will only let the pump run at 51% capacity without tripping on high amps. I am wondering if there were any suggestions as to why high amps might be a problem. Flow is much lower than expected as well.
The VFD will only let the pump run at 51% capacity without tripping on high amps. I am wondering if there were any suggestions as to why high amps might be a problem. Flow is much lower than expected as well.





RE: Pump Amp Problems
Capacity refers to flow when dealing with centrifugal pumps; flow at what VFD setting? Or by capacity did you mean VFD setting (51% of 50 or 60 hz, 25.5 or 30.6 hz?)
If it is an axial flow pump (high flow low head) then horsepower requirement will rise near shutoff. Maybe there is no problem other than higher than anticipated system resistance forcing the flow back on the pump curve. This is unlikely, in most cases impossible, to cause a trip at half speed.
Confirm direction of rotation (do this while watching the spin-down.)
RE: Pump Amp Problems
Best to you,
Goober Dave
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RE: Pump Amp Problems
Is this a new pump and motor or a retrofit vfd or a new motor or what?? If you can also say what is the 50% is as 1 Gibson says would help a lot.
So far all we have is you saying you've got a problem. There are many possible issues, but give us data and we might be able to help. No more info all we can do is guess...
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pump Amp Problems
There are numerous drive parameters which could cause this. Here's a few to start with:
- wrong volt/Hz setting, if this is a scalar drive
- bad or no auto-tune, if this is a vector drive
- wrong motor connections
- wrong motor rating in config settings
- wrong current limit in config settings
- wrong base voltage in config settings