AquaRite TurboCell-15 issues

[bmcmullin]

Folks. Here's is a summary of the system, situation and symptoms:

- AquaRite controller and T-15 salt cell circa 2009
- 25,000 Gallon pool in northeast (Nova Scotia). Pool usually open 3 months with pump on 12 hour on/off cycle.
- 500lbs of salt at opening about a month ago. Same amount as previous years.
- SWG worked fine for three weeks then started tripping off on "High Salt" but I'm suspect of the accuracy of this reading

While generating here are the readings:

- 4,800
- 77
- 23.6V
- 7.65A
- 21%
- 4,900
- AL-3
- r 1.40

After it trips and not generating

- 4,800
- 77
- 31.1V
- 0.00A
- 21%
- 0
- AL-3
- r 1.40

The inrush current limiter/thermistor has a tiny what appears to be a burn mark on the top edge. As this thermistor is a known problem with these units, I suspect this may be all or part of the problem. I measured the temp of it while generating and it was 131C/268F. I have a replacement coming tomorrow but something tells me there's something else wrong. My hunch is that the salt cell has reached the end of it's useful life. My question is whether a worn salt cell could yield an incorrect salt reading. I couldn't find any posts that indicate such.

Appreciate any guidance anyone has to offer.

Regards,

Bill

 

[JamesW]

The 7.65 amps indicates that the salinity is probably very high.

If the amperage gets to 8.0, it will say high salt.

You need a K-1766 salt test kit or a good meter to check the actual salinity.

If the cell is after a heater, the increased water temperature while the heater is on will increase the amperage above 8.0.

 

[JamesW]

Why do you have to add so much salt?

Are you getting significant dilution?

How are you measuring the salinity?

 

[bmcmullin]

Why do you have to add so much salt?

Are you getting significant dilution?

How are you measuring the salinity?

The salt requirements on opening (starting from zero salt) calls for about 600lbs. I put 14 bags at 44lbs per bag. Same as previous years. I didn't test the salinity as I don't have a kit but it seems that I should do that based on the responses. Will order a test kit presto.

 

[JamesW]

Salt doesn't go anywhere. So, the salt should not need to go from zero every year.

 

[bmcmullin]

Salt doesn't go anywhere. So, the salt should not need to go from zero every year.

Oh my. This might just be the learning moment of the year. Honestly never crossed my mind that salinity at opening would be anything more than zero. I've opened the pool for 9 years the same way, although I think I may have went with 14 bags this year versus 12 last year. I can't remember why. Gotta get the test kit. If the SWG is working right, this would be a cheap lesson. Thank you!

 

[bmcmullin]

Salt doesn't go anywhere. So, the salt should not need to go from zero every year.

JamesW. You nailed it. Did a salinity test and sure enough it reported nearly 5,000ppm. Started the drain/refill dilution exercise yesterday.

 

[bmcmullin]

Salt doesn't go anywhere. So, the salt should not need to go from zero every year.

Update. After taking down the water level a few inches and refilling, the instant salt reading is down to 4,300 and the cell current 7 amps. The controller trips off on High Salt after 5-10 minutes. If 8 amps is the limit that triggers High Salt then it would seem that there is another contributor to the problem. I wonder if the inrush current limiter/thermistor could be delivering inaccurate measurements to the controller? I have a new one which I intend to install to see if it makes any difference. I also have a new salt cell coming. I know that it's likely not the problem or part of the problem but since the one in operation is 9 years old, it is likely near end of life. Everything I've read says they last about 5 years, although I don't know if that assumes year-round operation. I'm in the northeast so the SWG runs max four months out of the year.

 

[JamesW]

Are you sure that the amperage is not at 8.0 when the high salt light comes on?

Do you have a heater?

If yes, the amperage will go up significantly when the heater is on.

 

[bmcmullin]

Are you sure that the amperage is not at 8.0 when the high salt light comes on?

Do you have a heater?

If yes, the amperage will go up significantly when the heater is on.

I do have a heater but it wasn't running yesterday as the pool was above heat pump set temp. I didn't watch the display at the time of the trigger off but I will definitely do that and report back.

 

[JamesW]

Ok, I suspect that the salinity is still too high. Just bring it down until the amperage is consistently below 8.0.

If the heater is on, the amperage will go up. So, you need to account for that.

 

[bmcmullin]

I have confirmed that the cell amperage does rise to 8 and then the controller triggers off on High Sale. I did a test yesterday for fun by putting the hose in the skimmer and turning the valve to skimmer only, theorizing that by diluting the water going to the cell the salinity and amperage would drop. As you might expect, they did. Now just have to drain quite a bit of water and refill.

 

[bmcmullin]

Ok, I suspect that the salinity is still too high. Just bring it down until the amperage is consistently below 8.0.

If the heater is on, the amperage will go up. So, you need to account for that.

Update. Progress but a new issue.

I took the water down about 12" over the last two days and added fresh water (city water). 12" is about 20% of the water assuming the average depth of the water at 5'. The instant salt reading is now down to 4,100 from 4,700. I would have expected the salt level to have gone down more. I confirmed with a salinity test strip that the salinity reading from the controller is correct. I also replaced the salt cell with a new T-15 (old one was 9 years old) and I also replaced the thermistor/inrush current limiter.

Here's the new issue. After draining and refilling, and before replacing the cell and thermistor, chlorination starts runs for 15 mins to an hour then appears to stop. I say appears to stop because it is not stopping on High Salt. My basis for believing it is stopping is that the controller display shows 0 current draw for the salt cell and the thermistor has gone from hot to cold. When I reset the controller, going from Off to Auto, the thermistor gets hot within a minute. While it's running, the amperage is around 7. Even after the amperage goes to 0, the Chlorination green light is still on. Same symptoms after replacing the salt cell and thermistor.

One thing I didn't mention in my original report is that a couple of weeks ago the controller displayed a "PCB Err". After a hard reboot the error went away and has not returned.

 

[chlorinatorpro]

If your duty cycle is still set to 21% with a r1.40 board , that means the cell is on for 25 minutes, then goes off for 95 minutes and repeats that cycle for however long your pump runs. Try turning the duty cycle up to 65-70% and see how that works and then begin to dial it down as the summer progresses. r1.40 boards have a 120 min total cycle.

 

[JamesW]

The cycle time is 120 minutes for revision 1.4. Current cycle time is 180 minutes.

The percentage reported earlier was 21%.

So, the cell will generate for 25 minutes and then it will stop producing for 95 minutes.

Then, a new cycle will begin.

The generating light stays on the entire time, even when it's not actually generating.

When it's not generating, the amperage and instant salinity will be zero.

To go from 4,700 ppm to 4,100 ppm, you would need to replace about 13% of the water.

This calculation is available in poolmath.

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www.troublefreepool.com

 

[bmcmullin]

Chlorinatorpro and JamesW, I am exceptionally grateful. Not sure how you knew about the duty cycle but not surprised you had the answer. I re-read the manual for the AquaRite and that info is not in there...unless I missed it. I have to ask, how did you know?

 

[JamesW]

The documentation is not very good. I read about it somewhere a while back, but I don't remember exactly where.