Recommendations on Pump Speeds?

[Kit]

I have an in-ground 2,500-gallon, saltwater spa with an IntelliFlo VS pump. I have set up the EasyTouch4 control panel with 2 pump circuits: (1) "Pool circuit" for general filtration & chlorine generation & (2) "Spa circuit" for when the spa is in use. The PB initially set up the pump speeds as follows: Pool circuit = 1,800 rpms; Spa circuit = 2,000 rpms. Should these speeds be increased or decreased? Does 1,800 rpms in the pool circuit create a sufficient water flow for the IntelliChlor SWG to produce chlorine?

Thank you for your help.

Kit

 

[pooldv]

I run mine at 1100 rpm for skimming, filtering and making chlorine with the SWG.

 

[Kit]

I run mine at 1100 rpm for skimming, filtering and making chlorine with the SWG.

I trust that 1,100 rpms is adequate for chlorine generation. I did read in the IntelliChlor manual that below a certain rpm the flow rate won't be sufficient to generate chlorine. However, I cannot find anything in the manual that specifies that rpm.

 

[pooldv]

There is a flow sensor in the intellichlor that will give a low flow error if the flow is inadequate. Mine gave occasional low flow errors at 900 rpm, a few low flow errors at 1000 rpm and no low flow errors in 5 years at 1100 rpm, even with a dirty filter.

 

[xyz]

I'm at 1200 and have no issues. The reason for the desire for lower speeds is power consumption. At 1200 RPM it draws 160 watts. At 2400 RPM it is about a thousand watts. So even if I run it 2 or 3x as long, I still use far less power.

 

[pooldv]

Yes, +1 to that. Mine uses 150 watts at 1100 rpm. At 10.25c/kWh I can run my pump 24x7 for less than 12 bucks per month.

 

[xyz]

And I'm getting approximately 70 GPM which gets me more than enough skimming and mixing with 8 hours a day.

But it now that I see pooldvs calc, I may just run mine more since i hadn't realized I my recent improvements lowered my costs so dramatically. ;-)

 

[GaryT58]

With my VS and SWG, I kept dialing back the RPM until the flow control error occurred, and then set the lowest at +150 just to allow for dirty sand filter.

 

[Kit]

Thank you, everyone, for your recommendations. Makes perfect sense to me. Although I didn't mention it in my original post, my objective is to set the speed at the lowest chlorine-generation level in order to minimize power consumption.

Very much appreciated!

 

[Kit]

As a follow-up.... I discovered that the pump speed of the IntelliFlo (IC20) needed to be set at >1,500 rpm in order for the flow light on the IntelliChlor to be "green". I thought that the speed was a bit high, but maybe that's characteristic of the IC20 as well as the length & diameter of the underground PVC plumbing.

 

[mas985]

Every pool plumbing setup is going to be different.

 

[xyz]

As a follow-up.... I discovered that the pump speed of the IntelliFlo (IC20) needed to be set at >1,500 rpm in order for the flow light on the IntelliChlor to be "green". I thought that the speed was a bit high, but maybe that's characteristic of the IC20 as well as the length & diameter of the underground PVC plumbing.

Since the IC20 has fewer plates than the 40 and 60, it is unlikely that the IC20 is the reason you need to be up at 1500. If anything, the IC20 would allow a "slight" lowering of RPM because it would have slightly less friction.

Recently, I replaced my very old 48 sq ft DE filter with an 80 sq ft DE filter, and replaced the higher friction plumbing [lots of elbows], and higher friction slider valve, with a high-flow valve, and lower friction plumbing with sweeps instead of elbows wherever I could. My max head pressure at the filter went from 40 psi to 20 psi. No surprise, my minimum "safe" RMP speed went from 1800 RPM to 1100 RPM.

So basically, it is the flow friction, also called head pressure that the pump us pushing against. While the IC will contribute to that it is a tiny portion. Your filter and elbows/plumbing are the lions share.

So if you want to drip your RPMs, look at higher surface area filter, and higher flow valves/plumbing. Finally, I forget who gave us this information, but the Intelliflo loses efficiency much below 1000 RPM, so there is little motivation to go lower.

To give you some info, going from 1800 to 1200 RPM on my system gets me from 415 watts to 164. So my power requirement was reduced by half. Pretty cool. At 1600, I'm at 317.