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# Eta of motor & pump

## Eta of motor & pump

(OP)
I am trying to understand the term Eta in relation to pumping. What is Pump Eta. What is Pump+Motor Eta. Is this an efficiency term and if so what is the difference between motor efficiency and pump Eta. How is pump Eta measured.
Any help would be greatly appreciated.

### RE: Eta of motor & pump

ETA = estimated time of arrival?

Greek later eta is sometimes used for efficiency.

I vote #2 is the likely useage

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### RE: Eta of motor & pump

It's a scrip N looking letter... is that eta or neta?

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### RE: Eta of motor & pump

(OP)
Thanks electricpete, but what I need is an explanation of the term as it applies to pumps and motors and a specific definition of how it is determined.

### RE: Eta of motor & pump

“What is Pump Eta”
fluid horespower / shaft horsepower

“What is [Pump+Motor] Eta”
fluid horsepower / electrical input power

“Is this an efficiency term”
my understanding of your most recent post is you agree in this context eta means efficiency.

“what is the difference between motor efficiency and pump Eta”
motor efficiency = shaft horsepower / electrical horsepower
pump efficiency = fluid horsepower / shaft horsepower

“How is pump Eta measured.”
Need someone else to answer that one.

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### RE: Eta of motor & pump

For a centrifugal pump, fluid or liquid hp = QH(sp.gr.)/3960

Q is gpm; H is the net head in feet; sp.gr. is specific gravity.

Following electricpete formulas, multipling both equations one gets:

total effy. = motor effy.× pump effy. = fluid hp÷electric hp.

The power input to the shaft is usually called brake horsepower (bhp) = electric hp × motor effy.

pump effy. = fluid hp÷(electric hp × motor effy.)

Knowing motor effy., electric hp, and calculating fluid hp as above, enables one to estimate pump effy.

### RE: Eta of motor & pump

chrisflood,

This might be what you have seen or looking for.

Dank off Eta Pumps are Solar ETA Pumps
An Eta pump are for solar water system, the applications for the Eta pump systems include:

Farming and irrigation
Cattle and livestock watering
Remote village water systems
Household potable water systems
Pond water transfer

You may look at http://www.scsolar.com/Dankoff_ETA_Pumps.html

Good luck

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