Using variable speed pool pump with SWG

[Rockman59]

I am considering converting to a variable speed pump. The vendor says I will save a lot of money my electric bill. They want to program the pump to run 7 hours a day at 1750 rpm and 3 hours a day at 2750 rpm. Now the question....is this enough time at the 2750 speed for my Intelichlor IC-40 SWG to make enough chlorine for my pool? I currently have a one speed pump that runs 8 hours a day at 3450 rpm and does the job. I am concerned that 3 hours a day at the 2750 speed and 7 hours at the 1750 setting will not produce enough chlorine for my 40,000 gallon pool. Comments please. And thank you in advance.

[mas985]

Pump speed has almost nothing to do with chlorine production as long as the minimum flow rate requirements are met. If 8 hours is enough for your old pump, 8 hours should be enough for your new pump. But the vendor's schedule is a little overkill in my book. 1-2 hours at 2500 and 7-6 hours at 1000 RPM should be enough run time (8 hour total). Most VS pumps have peak efficiency around 1000 RPM so I would target most of the run time around that.

[Rockman59]

mas985.....thanks for the info.

[Rockman59]

Currently running the variable speed pump at 7 hours at 1750 and 3 hours at 2750 and the IC 40 is making plenty of chlorine. I am considering cutting back to 7 hours at 1000rpm and 2 hours at 2500 rpm. I live in the SoCal desert where right now the highs are in the mid 90s which eats up the chlorine. Any comments?

[mas985]

Sounds reasonable. You may find that you can cut back even further.

[CarlD]

Interesting. Not familiar with VS pumps (only 2spd pumps). My SWCG can actually be wired to control the pump and the pump speeds, but I keep it simple, personally.

[Rockman59]

Update: I am still running my VS Pentair pump 10 hours a day....7 hours at 1750rpm and 3 hours at 2750rpm. My Intelchlor 40 SWG is pumping out plenty of chlorine running at 60%. I am considering cutting back on the pump runtime to save even more energy. With the VS pump I am now down about 40% from the energy useage of the single speed pump I used to have. Comments?

[mas985]

Why so high on the RPM levels? I thought you were going to reduce those.

I would target 1000 RPM for the lower speed and 2000 RPM for the higher speed and only for 1-2 hours.

[Rockman59]

Mas985 said: Why so high on the RPM levels?...................The rpm levels were programmed by the installer...he works for a very reputable long-established pool company and seems to know his business. Since I had no experience with VS pumps I went along with his suggestion of 7 hours at low rpms and 3 hours of faster rpms. I cut back to 6 hours of low rpm a few days ago and will be monitoring the water quality. My IC-40 chlorine generator is now set at 60% and still producing plenty. I started with it at 100%. As I mentioned I will be keeping a close eye on the pool. I also use a Pool Shark and it works well at the 2750 rpm setting....much slower at the 1750 rpm setting. My pool is a large one (48 feet, 40K gallons) so the Pool Shark has a lot of pebble tec to clean and I'm not sure it can get the job done at the 2000 rpm setting.

[Rockman59]

Got my first electric bill since the VS pump was installed a month ago. Useage down almost 50% from a year ago...same number of days in billing cycle, WX conditions also about the same. Amazing.