Variable Speed Pumps with SWG Systems

[Amadeus74]

Please forgive me if the following question has already been discussed on this forum. I searched the site as best I could but could not find anything.

How does a variable speed pump affect the efficiency and life span of a SWG system? Can a salt cell work as effectively at the slower variable pump speeds as it does with a standard one-speed pump? Would a cell wear out faster if you ran your pool pump 24 hours at a slow speed (say 20 GPM) versus running 8 hours per day at regular speed (80 GPM)? And for that matter, would not a variable speed pump & motor running at 24 hours per day wear out faster than a standard pump motor running at 8 hours per day?

Needless to say, I currently have a SWG system and a standard one-speed pump. I am considering buying a variable speed pump but am worried about how the slower pump speeds would affect my SWG system. Any information you could provide on this topic would be most helpful in my decision to possibly buy a variable speed pump.

Thank you.

 

[mas985]

Most SWGs can operate down to 15 GPM but check the manual. The efficiency and the lifetime of the cell shouldn't change much either as long as you are compensating for pump run time. A longer run time means you can turn the cell production down (lower %) so the actual on hours of the cell remains the same.

 

[JasonLion]

The SWG has a minimum flow rate that it requires to function correctly. Nearly all SWGs will shut down when they don't have enough water flow.

Most variable speed setups provide enough water flow to keep the SWG happy even on very low speeds. However, unusual plumbing or the occasional SWG that requires higher than average flow rates can limit the lowest speed you can use. The SWG should show an error if there is a problem, so it is fairly easy to adjust the speed until everything is working (if there is a problem, which is unlikely).

The extra stress/wear on the pump from running continuously is very very small, and there is a corresponding reduction in wear because of the lower speed. The net effect is that wear is essentially the same either way. The only at all common failure mode for variable speed pumps is electronics damage from nearby lightning strikes, and even that is reasonably rare.

 

[Amadeus74]

Thanks mas985 and JasonLion for your advice. That really helps. Do you recommend any brand or model of variable speed pump? I have a 20k gal pool with an AutoPilot SWG system.

Thanks again for your help.

 

[mas985]

Do you have a separate controller already? If so, what brand?

If not, then all the manufactures have VS pumps that have a built in controller. The Intelliflo VS 011018 is one of the best deals out there right now.

 

[Amadeus74]

Thanks for responding mas985. No I do not have a separate controller. The only controller I have is the DIG-220 for the SWG system.

I would prefer a variable speed pump with a separate controller that I could mount on a wall away from the sun and rain. Is there a VS pump with external electronics that you recommend?

 

[JasonLion]

They all have external control systems available as extra price options purchased separately.

I like the IntelliFlo best, though the EcoStar is very good (better in a few minor ways, worse in others).

 

[Amadeus74]

Thanks JasonLion for the advice.

What about the Ecopump and Leafpump systems that have three year warranties vs. just one year warranties with the Hayward, Jandy, and Pentair VS pumps? Have you had any experience with them?

 

[JasonLion]

The EcoPump is a two speed pump, not in the same league with the variable speed pumps. I've never heard from anyone who has a LeafPump.

 

[Amadeus74]

Thanks JasonLion.

So, it's probably wise to stick to the major brands (Pentair, Hayward, Jandy). You know, my pool is 19 years old now, and I still have the original Hayward pump that was installed when the pool was built. I've had to replace the motor a couple of times, but that's it. Not a bad track record for Hayward products.