Who has the authority? Pump or Motor 8

[CrazyHorse81]

Ok. Lift station grinder pump. So does the pump tell to motor how much to work or does the motor say "I'm only going to give you what I'm made for!"

I think that the pump dictates the motor how hard to work, but don't exactly why.

Q: What would cause the pump to pump more flow at a lower head? A: A lower TDH. So at some point in time, the lower TDH relates to no discharge at the manhole. Then what happens? More cycles?

Please enlighten me!

 

[CrazyHorse81]

I simply meant to agree to the standalone statement made by waross. "Hint. An obstruction will (counter intuitively) be in the pump system with the LOWEST current." But I was not agreeing to it in this particular case.

I do think that there is mechanical loss - like you said impeller binding, worn impeller, etc.

My apologies everyone. I am finding out the hard way how to communicate well in these forums. I notice the confusion once one points them out to me.

 

[Artisi]

Question - is the low powered pump running the right direction?

A worn impeller will reduce power as well as flow.

Don't stress about not being clear, trouble shooting at a distance is not easy even for the best of us.

In an ideal world the way to proceed is to check flowrates for each unit against a discharge pressure reading against power input, compare inlet and discharge configurations, check pump spec.against each other for same motor size, same impeller diameter, check previous history etc etc.

Rememer, there is always a solution - however obscure it might be.