120V vs 240V - Superflo VS Pump - More efficient at 120V?

IASteve

Active member
Aug 27, 2017
33
Central Iowa
Looking at the Superflo VS pump specs:
115-volt: WEF 7.3 THP 2.2
230-volt: WEF 6.6 THP 2.2

Does this mean it is more efficient at 120V than 240V?
I know I'll get a higher flow rate at high speeds at 240V, so I may go that route anyways.
Any reason to go for one voltage over the other? Current pump is 120V, but I can re-wire easily.

Thanks!
 

markayash

Gold Supporter
Mar 21, 2016
1,550
Marrietta Ga
My understanding is the pump will run the same at 120 vs 240 just draw more amps' at 120 but same watts..But I have also heard 240 has less heat buildup and can use a lower gauge wire.
Curious to see what the electricians here say
 

JamesW

TFP Expert
Mar 2, 2011
18,498
The pump will not perform at the same flow level at full speed at 115 volts.

Other than that, it should be about the same efficiency.

My preference is to use 230 volts whenever possible.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,235
Pleasanton, CA
Looking at the Superflo VS pump specs:
115-volt: WEF 7.3 THP 2.2
230-volt: WEF 6.6 THP 2.2

Does this mean it is more efficient at 120V than 240V?
Where did you get the WEF numbers from? More than likely, they are at two different speeds. If you compare the two pumps at exactly the same speed, they should be about the same efficiency.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,247
Northern NJ
Where did you get the WEF numbers from?
Pentair website.


More than likely, they are at two different speeds. If you compare the two pumps at exactly the same speed, they should be about the same efficiency.
Performance curve from...


See the 3450 RPM difference between 110V and 230V.

 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,235
Pleasanton, CA
The performance curve in the brochure is different than the one on the web page. But I believe they are reducing the RPM as the move from left to right on the head curve so as to reduce the maximum power draw. To claim that both are 2.2 THP is also a bit misleading as well because the RPM modification technically reduces the maximum THP of the motor.

So the short answer is to ignore those numbers as they are not a good comparison. They relate to two different RPM values and they don't really say what the associated plumbing curve is for those valves so they are meaningless.
 

JamesW

TFP Expert
Mar 2, 2011
18,498
From the manual, the maximum amps at 115 volts is 13.2. So, that limits the watts to 1,518.

The maximum amps at 230 volts are 11.5. So, that limits the watts to 2,645.

The pump must be reducing the rpm as needed to keep the amp draw below 13.2 when the voltage is 115.

The WEF (Weighted Energy Factor) implies a better efficiency for 115 volts, but I don't think that that's realistic.

Maybe they got different numbers based on the reduced flow at higher speeds.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,235
Pleasanton, CA
Maybe they got different numbers based on the reduced flow at higher speeds.
That is exactly what they did. They chose a plumbing curve that is not identified and determined the flow rate and power usage for each pump which are different. So not a fair comparison.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,235
Pleasanton, CA
No, they don't have different sized impellers. Otherwise, the head curves for the other speeds would be different as well as the max head at max RPM would be different. The only explanation to the shape of the head curve is that the power/RPM is being limited in the 115v version.
 
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