Flow control (bypass) valve for Intellichlor IC20

[sjoshi]

Hello all, first time pool owner.. set up has a 15K gallon pool + SPA, IC20 SWCG and a 3 HP Pentair variable speed, also a heater. Set up is sweet, there is a control pad in the family room that can manage multiple things including pool / spa mode. My question --> the set up currently has a bypass loop with a valve that seems to partially (30% to 50%?) open. Plumbing seems to have an outer dia of about 2-1/4 inch.

My questions are:

1. I have heard such valves may or may not be needed on a variable speed set up - is this correct? Do I need the valve operating?
2. How do i determine the best setting for the valve? 30% open vs 70% vs fully open?

Thank you all in advance for your help!

 

[needsajet]

If it's a bypass around the SWCG, it could be to reduce FC accumulation when in 'spa only' mode. You could also turn down the SWCG and achieve the same result.

As far as best setting, you'd need to monitor spa and pool separately under various operating conditions, and find an appropriate amount of bypass over time that would work across various operating conditions. Allowing the spa to spill over into the pool would likely eliminate such a concern, but likely won't be suitable when you want to use the spa but prefer not to lose heat into the pool.

Welcome to TFP. Good to have you here

 

[wireform]

Pictures of your equipment pad can help us clarify what you have.

 

[sjoshi]

Hi I have attached a pic of the bypass (flow control) valve set up. It is the valve at the bottom of the picture, set to be partially open. Appreciate your help!

 

[mknauss]

With a variable speed pump, that seems to me to be totally unnecessary. You are just having to run your pump at a higher rpm to satisfy the flow switch on the SWCG.

 

[sjoshi]

If it's a bypass around the SWCG, it could be to reduce FC accumulation when in 'spa only' mode. You could also turn down the SWCG and achieve the same result.

As far as best setting, you'd need to monitor spa and pool separately under various operating conditions, and find an appropriate amount of bypass over time that would work across various operating conditions. Allowing the spa to spill over into the pool would likely eliminate such a concern, but likely won't be suitable when you want to use the spa but prefer not to lose heat into the pool.

Welcome to TFP. Good to have you here

TY. I am not sure it is for the spa mode. The intellichlor is controlled by a Pentair panel, and it seems to adjust the salt generation (%) for pool vs spa. Eg. a 60% level for pool (out of possible 100%) shows below it a 3% level for spa.

 

[JoyfulNoise]

SWG’s are not sensitive to flow. As long as you close the flow switch, around 10-15GPM, the unit produces chlorine at a rate that is independent of flow through the cell.

Normally one attempts to bypass a heater to reduce head loss from a heater when the heater is not needed.

 

[sjoshi]

With a variable speed pump, that seems to me to be totally unnecessary. You are just having to run your pump at a higher rpm to satisfy the flow switch on the SWCG.

TY! So if I shut off this valve, and the overall flow is say in the 150 gpm range (not actually sure what it is).. would the pump operate at lower rpm for the same flow, or would the flow now go down? Just beginning to learn!

 

[sjoshi]

SWG’s are not sensitive to flow. As long as you close the flow switch, around 10-15GPM, the unit produces chlorine at a rate that is independent of flow through the cell.

Normally one attempts to bypass a heater to reduce head loss from a heater when the heater is not needed.

TY! So even a modest closure (eg. leaving the valve open say 70%) should do the trick since the remaining flow would go thru the SWCG?

 

[JoyfulNoise]

TY! So even a modest closure (eg. leaving the valve open say 70%) should do the trick since the remaining flow would go thru the SWCG?

That’s fine.

I suspect the builder did this so you can remove the cell and clean it without having to shut down the pump. But the reality is, if your pool water is properly balanced and the saturation level is carefully maintained, you almost never need to clean the cell.

 

[JoyfulNoise]

However … I just noticed the placement of the valve and the fact that’s there’s no check valve to stop reverse flow … so whatever the PB was doing, they clearly had no clue.

 

[Jimrahbe]

s,

There is just no reason to have that by-pass at all.

If this were my pool, I would set the valve so that ALL the water passes through the cell. This will allow you to run your VS pump as slow as you can and still make chlorine.

Thanks,

Jim R.

 

[mknauss]

Pentair shows this type of installation when you will have a large hp single speed pump. But with a VS pump, there is simply no need.

 

[JoyfulNoise]

Pentair shows this type of installation when you will have a large hp single speed pump. But with a VS pump, there is simply no need.

Alternate translation :

Actually reading the equipment installation manual is hard …

 

[sjoshi]

Ok TY much all!

 

[needsajet]

However … I just noticed the placement of the valve and the fact that’s there’s no check valve to stop reverse flow … so whatever the PB was doing, they clearly had no clue.

this one seems to be a high probability