VS pump question

[Steve319]

I could use some understanding of how to best set my vs pump to work best with my IC20 SWG. I currently have the VSP set to run at 2350 rpm from 6am to 6pm and 1200 rpm from 6pm to 6am. The lower speed in the evening is me trying to be economical and partially out of respect for my neighbor who would hear the motor if sitting out on their lanai after work.
My question is what is the best speed for the pump to work with my SWG? I have been able to stabilize my FC at around 7.5 - 8.0 but in order to do this I have been reducing my SWG to 10 or 20% output. Is it better to have the SWG at 40% and lower the speed from the 2300 rpm to maybe 1700 rpm or does one have nothing to do with the other? In case it's needed I have attached todays test #'s (working on lowering the PH but that's a work in progress).
Thank you

 

[mknauss]

At what rpm does the flow switch close to operate the SWCG? If that rpm provides skimming to your pool, then that would be the base level rpm you would run at.
Then you can have separate rpm settings for your heater, etc.

 

[Steve-D]

As it has been explained to me pump speed only impacts Chlorine output from your SWG if the pump is running so slow that it generates no FC (the "slow flow" indicator on your IC20). If the pump is running above that "slow flow" threshold the SWG will always generate some FC unless you set it at 0%. The factors to consider are the SWG % setting and pump runtime.

A quick google search says that the IC2 puts out 0.7 pounds of Chlorine over 24 hours...that would be at its max (100%) setting. If you run the SWG at 50% for 24 hours it will put out 0.35 lbs of FC whether you run the pump at 2350 0r 1200 rpms (assuming that at 1200 you are not tripping the "slow flow warning). If you run the pump only 12 hours a day at 100% SWG it will generate 0.35 lbs of FC at either speed.

Basically running it at 40% means the SWG is "on" 40% of the time...at 20% it is "on" (generating FC) 20% of the time. It took several "yes but..." conversations here for me to wrap my head around this.

 

[Steve319]

At what rpm does the flow switch close to operate the SWCG? If that rpm provides skimming to your pool, then that would be the base level rpm you would run at.
Then you can have separate rpm settings for your heater, etc.

not sure what rpm causes the flow switch to close. I'm guessing the best way is to lower the rpms until I see the flow light go off, then use that as my base. Thank you

 

[mknauss]

not sure what rpm causes the flow switch to close. I'm guessing the best way is to lower the rpms until I see the flow light go off, then use that as my base. Thank you

Correct. When you find what rpm closes the flow switch, add 100 rpm to that so it will not be effected by a filter slowly getting dirty.

 

[Jimrahbe]

319,

Lower your RPM until the flow light turn Red. Then slowly increase your RPM until the flow light turns Green. Then add a 100 or 200 RPM and call it good.

Thanks,

Jim R.

 

[Steve319]

As it has been explained to me pump speed only impacts Chlorine output from your SWG if the pump is running so slow that it generates no FC (the "slow flow" indicator on your IC20). If the pump is running above that "slow flow" threshold the SWG will always generate some FC unless you set it at 0%. The factors to consider are the SWG % setting and pump runtime.

A quick google search says that the IC2 puts out 0.7 pounds of Chlorine over 24 hours...that would be at its max (100%) setting. If you run the SWG at 50% for 24 hours it will put out 0.35 lbs of FC whether you run the pump at 2350 0r 1200 rpms (assuming that at 1200 you are not tripping the "slow flow warning). If you run the pump only 12 hours a day at 100% SWG it will generate 0.35 lbs of FC at either speed.

Basically running it at 40% means the SWG is "on" 40% of the time...at 20% it is "on" (generating FC) 20% of the time. It took several "yes but..." conversations here for me to wrap my head around this.

Steve, your Mark Twain quote is spot on! So if I am understanding correctly, I can run my VSP at a lower speed as long as it does not trigger the low flow without affecting the amount of chlorine generated by my SWG. In order to keep my FC at acceptable levels I need to continue adjusting the SWG output.
Thank you

 

[Steve-D]

if I am understanding correctly, I can run my VSP at a lower speed as long as it does not trigger the low flow without affecting the amount of chlorine generated by my SWG. In order to keep my FC at acceptable levels I need to continue adjusting the SWG output.

Exactly!

Many of the TFP recommendations are cost/benefit driven like:

• Running the SWG at a lower % of its maximum should extend the life of the cell so you don't have to replace it as quickly as you might otherwise
• Running the pump at a lower speed costs less to operate than at a faster speed by using less electricity
• Targeting a FC level not likely to drop below minimum recommended levels to mitigate against "oops" and the need for a SLAM

Every pool is different and you will need to find the balance that most closely matches your goals. For me electricity is more expensive during the day so I run my pump slower (1750) most of the time but "surge" it for 90 minutes overnight at off-peak rates to gain more filtration and improved circulation.

If you can mange FC and keep the pool skimmed at 1200 rpms 24x7 then that is the least expensive and arguably the "best" option. If you need to run it at 2350 for 12 hours to get the daily filtration that you need then that's "best". "Best" may fall somewhere in-between and will be subjective depending on what meets your needs balancing cost against benefit.

 

[Steve319]

One more question, if running VSP at 1700 rpm 24/7 should pump speed be increased when vacuuming for better suction?

 

[Jimrahbe]

319,

Yes, that is the whole point of having a VS pump. You can run it at your lowest speed for energy costs most of the time, but always have the option to increase the speed to do the job at hand. As an example:

I run my pump at 1200 RPM most of the time, but when I want to run my waterfall, the pump ramps up to 2800 RPM. etc.

Thanks

Jim R.

 

[Steve319]

319,

Yes, that is the whole point of having a VS pump. You can run it at your lowest speed for energy costs most of the time, but always have the option to increase the speed to do the job at hand. As an example:

I run my pump at 1200 RPM most of the time, but when I want to run my waterfall, the pump ramps up to 2800 RPM. etc.

Thanks

Jim R.

Thank you Jim