SWG run time calculations assistance

[mas985]

Then there is likely a very large obstruction in the suction side or the impeller. If the pump is not drawing in air into the pump basket, then it is likely an impeller issue.

 

[sbcpool]

Maybe a missed labeled RJ20+ (0.9 lbs per 24 hours) cell?

That was one of my initial thoughts, but I think there are more plates in the RJ60+ and nobody commented that I had the wrong number of plates.

 

[sbcpool]

Then there is likely a very large obstruction in the suction side or the impeller. If the pump is not drawing in air into the pump basket, then it is likely an impeller issue.

Hmmm :/ Definitely something to explore, but for now it work in my favor in terms of diagnosing this issue. I'm out of options at this point. We've ruled out circulation, algae, water chemistry, and now flow rate. Is there anything else to rule out aside from the cell itself?

 

[mas985]

That was one of my initial thoughts, but I think there are more plates in the RJ60+ and nobody commented that I had the wrong number of plates.

I believe the plates are just shorter for the lower output cells. Can you post a picture of the entire cell?

 

[sbcpool]

I don't think they could fit a longer cell in there.

 

[mas985]

I think that is the correct cell. Voltage and amps match as well. If it was a smaller cell, the amps would be less and salt reading would be way off when the controller is selected for the RJ60+.

 

[sbcpool]

Well, we're in the interesting place where everything checks out yet the production is still only 30% of rated output. I don't even know what to try at this point.

 

[sbcpool]

If pushing x current through these cells into brine has to generate y amount of chlorine, then it stands to reason that the chlorine is either not being dissolved, or is combining with something else. I don't know what else there can be, even theoretically speaking. And if it's something in the water it has to be something present in fresh tap water.

Is it possible that the controller's amp reading is incorrect?

 

[JamesW]

How many plates are there and what are the dimensions of the plates?

 

[sbcpool]

13 plates. Not sure how I can measure them inside the cell.

 

[sbcpool]

I was using my phone to look my closely at the plates when I noticed that some of them appear to have a cut between them. Other than that, I can't see anything unusual.

 

[sbcpool]

Am I right in reasoning that if the cell was successfully producing 3.1 lbs/day at a flow rate of 40 gallons per minute, we would expect the effluent to measure about 6 ppm above the pool's FC?

Adding 6 mg to every liter that passes through the cell for 24 hours gives 3.1 lbs.

 

[mas985]

3.1 lbs in a 20k pool is an 18 ppm rise. Your 1 lbs/day is a 6 ppm rise.

Flow rate should not matter.

Adding 6 mg to every liter that passes through the cell for 24 hours gives 3.1 lbs.

Yes but you are passing ~60k of water over 24 hours @40 GPM or 3 turns which would be 3x 6 ppm. Over 8 hrs it would be 6 ppm rise.

 

[sbcpool]

I'll capture some output directly from a return and see what I get. That's straight from the horse's mouth so to speak.

 

[sbcpool]

FC 5.2 collected from the skimmer box and 6.4 collected from a return.

 

[JamesW]

The T-15 has 13 plates. The plates are 2.5" x 6". If your plates are the same size as the T-15, the cell should have an equal output. In my opinion, 3 lbs per day is not a realistic number.

The T-15 is rated at 1.47 lbs per day, but I don't know if that's a maximum or an average output.

Maximum output happens at 7.9 amps.

If we assume that the 1.47 lbs/day is at 7.9 amps, then the actual output should be relative to the amps.

Assuming 6.2 amps, the output would be 6.2 ÷ 7.9 x 1.47 = 1.15 lb. per day.

The theoretical maximum output is determined by the amperage.

The measured amperage needs to be multiplied by 6 since there are two sets of 6 cells in series with the sets in parallel.

The total amperage is 6.2 x 6 = 37.2.

Some of the power might be going to heat.

 

[sbcpool]

The T-15 has 13 plates. The plates are 2.5" x 6". If your plates are the same size as the T-15, the cell should have an equal output. In my opinion, 3 lbs per day is not a realistic number.

The CircuPool plates appear to be somewhere around 8 inches long and also about 2.5 inches. If the 3.1 lbs/day is not a "real" number I would feel like I was tricked into selecting CircuPool over more well-known and established brands like Pentair and Hayward I would have selected otherwise.

 

[JamesW]

The T-15 has one power wire going to the center plate and the other power wire goes to the two outer plates.

This creates two sets of 6 cells in series. The voltage for each cell is 1/6 of the measured voltage. If the voltage is 24 volts, that's 4 volts per cell.

Maybe your cell has one power wire going to one outer plate and the other power wire going to the other outer plate.

That would create 12 cells in series and the amperage would be 12 x 6.2 = 74.4, but the voltage per cell would be 2 volts.

If the voltage per cell was half, I suspect that the output would be significantly less.

I don't know how the manufacturer came up with the output rating.

Maybe contact them to inquire if they have test results that support their claimed output.

Ask them for something to validate their claimed output.

If they're really getting 3 lbs per day, then their cell is twice as efficient as the Hayward cell and that's highly unlikely.

In my opinion, 3 lbs per day is not a realistic number.

 

[Brett S]

For what it’s worth, I tried a similar test with my RJ-30+. I ran it at 100% for four hours after the sun had gone down. The FC level in my 14364G pool went up by 2ppm after that run.

That is certainly in line with the promised 1.5 lbs/24 hour output promised by circupool for the RJ-30+.

 

[sbcpool]

Maybe contact them to inquire if they have test results that support their claimed output.

Ask them for something to validate their claimed output.

If they're really getting 3 lbs per day, then their cell is twice as efficient as the Hayward cell and that's highly unlikely.

In my opinion, 3 lbs per day is not a realistic number.

I did contact them a few days ago and explained the issue. The representative was a little hostile and asked me what the problem was since there was chlorine in my pool. I tried stating it differently, explaining that at the rated output I should need a runtime of x hours, but instead I needed a runtime of 3x hours. He asked how I knew that, and I explained running the pump for various lengths of time and measuring the free chlorine in the pool. He told me "I don't know what you're trying to accomplish with these experiments," and told me again that he doesn't see the problem. He said CircuPool's policy is that if the unit makes chlorine (any amount) and there's no trouble lights on the unit, then it's working as designed. If you dig in their Troubleshooting Guide they use the same language on page 6: