Flow Rate the Same???

JamesW

TFP Expert
Mar 2, 2011
20,296
https://aquamagazine.com/service/how-to-read-pump-system-curves.html

To get an idea of where your pump operating point will be, you can graph your "System Curve" on the same graph as the pump head curves.

The intersection of the two gives you your operating point.

However, this is rarely useful. Most of the time, you just adjust the speed of the pump RPM until the flow is doing what you need it to do.

Is there any specific reason you need to know the actual flow rate?
 

Mlamb

Member
Oct 2, 2017
23
Sarasota/Fl
Since the pool was built, 23 years ago, I’ve had a 1 ½ HP (SF 1.10) single speed pump that I’ve replaced several times. The pump is making a all too familiar noise, so I think it’s on the way out. I would like to replace it with a 3hp two-speed pump. The fountain and spillway are on for the eight hours I run the pump (wife likes it that way, so I deal with the PH). I want to be able to run on low speed to save electric costs and still have the fountain and spillway on and good skimming. So before I spend money on a two speed, I would like to get a sense whether it will do what I want.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,700
Pleasanton, CA
Since the pool was built, 23 years ago, I’ve had a 1 ½ HP (SF 1.10) single speed pump that I’ve replaced several times. The pump is making a all too familiar noise, so I think it’s on the way out. I would like to replace it with a 3hp two-speed pump. The fountain and spillway are on for the eight hours I run the pump (wife likes it that way, so I deal with the PH). I want to be able to run on low speed to save electric costs and still have the fountain and spillway on and good skimming. So before I spend money on a two speed, I would like to get a sense whether it will do what I want.
Even the largest two speed pool pump will not produce anything close to same flow rate as full speed with a 1 1/2 HP pump. Even if you could find a pump that would, the efficiency of low speed is much worse than on high speed so you would end up using more energy, not less. Even a VS pump will not be much benefit unless you are willing to reduce the flow rate.
 

Mlamb

Member
Oct 2, 2017
23
Sarasota/Fl
Even the largest two speed pool pump will not produce anything close to same flow rate as full speed with a 1 1/2 HP pump. Even if you could find a pump that would, the efficiency of low speed is much worse than on high speed so you would end up using more energy, not less. Even a VS pump will not be much benefit unless you are willing to reduce the flow rate.
 

JamesW

TFP Expert
Mar 2, 2011
20,296
I think that the currently available models of the TriStar VS are W3SP3206VSP and SP32950VSP, which is the “Expert” line.

As far as I can tell, the expert line has a 4 year warranty vs. a 1 year warranty for the regular pump.

The SP32950VSP has an upgraded seal.

Both come with a controller and should work with AquaLogic 2.65 or higher.

Early versions of the AquaLogic software have limited functionality, but they should work.
 

Mlamb

Member
Oct 2, 2017
23
Sarasota/Fl
I think that the currently available models of the TriStar VS are W3SP3206VSP and SP32950VSP, which is the “Expert” line.

As far as I can tell, the expert line has a 4 year warranty vs. a 1 year warranty for the regular pump.
Thanks
The SP32950VSP has an upgraded seal.

Both come with a controller and should work with AquaLogic 2.65 or higher.

Early versions of the AquaLogic software have limited functionality, but they should work.
Thanks
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,700
Pleasanton, CA
I see two models, one with a keypad on the pump and one without. With my aqua logic ps-8 which one do I want?
I think you are looking at older versions of the pump. Hayward use to sell a version without the keypad but I don't think they do anymore. The model number would end in ND for no display.

 

Mlamb

Member
Oct 2, 2017
23
Sarasota/Fl
I think you are looking at older versions of the pump. Hayward use to sell a version without the keypad but I don't think they do anymore. The model number would end in ND for no display.

I see that now...thanks.