I have an Aqualogic PS8, about 3 1/2 years old. For over a year, due to consistently low chlorine levels, I've resorted to manually dosing the pool with liquid chlorine. I could not figure out why the chlorine was always low until one day I carefully observed the "diagnostics" display. The SWG was set at 75%, but it was only on for 24 minutes of the first hour of the cycle, and then it did not turn on again for the rest of the cycle. Running two cycles a day meant the SWG was only on for a total of 48 minutes.

I can manually restart the SWG by pressing the + or - and it will stay on for 24 more minutes before shutting off and staying off the rest of the cycle, unless I manually restart it again.

I experimented with different %:
Between 30 and 90%, the SWG is on for only the first 24 minutes of a cycle.
At 10%, it is on for the first 12 minutes.
Superchlorinate runs as long as it is set for.

The cell is clean.
Water chemistry is within ranges
Water temp is not a factor as this is a year-round issue except Dec and Jan when water is too cold.
There are no warning lights or error messages.

I pulled the circuit board today but found nothing amiss. It is very clean and shiny, looks like new.
Anyone encounter this problem???

Welcome to the forum.

I'm sure the SWG experts will be along shortly to advise you on what's going on.

Since it's staying on for exactly 24 minutes after a start, it seems intentional. Like a timer is set or something. Seems to me that if it were something heating up and shutting it down it vary the time.

Most of the time, SWG problems like the one you describe are actually caused by improper chemical levels. You said that "Water chemistry is within ranges", but that could mean just about anything. Could you post a full set of water test results so we can verify you are using the appropriate set of ranges?

The kind of failure you describe is possible in theory, but extremely unlikely. It is far more likely that you have made some incorrect assumption somewhere along the line. Have you tracked the on/off state through an entire cycle? Or have you only followed the cycle until the moment where the cell turned off?

I have an Aqua-Logic Plus unit. I have noticed something similiar. Occasionally I can trigger (or try to trigger) a chlorine production cycle by pressing the + key in the manner you describe. However the output to the cell never comes on! This condition seems to be brought on by pH levels above 7.6. Unfortunately I have never been able to find a way to consistently trigger this issue. Without that I had no hope of getting Hayward to address the issue.

Thank you so much for the speedy responses.
Chemistry:
tc 1.5 and free chlorine 1.5, but only because I dosed it manually with liquid chlorine
pH 7.5
Salt 3200
CYA 60
Alkalinity 110
Calcium 250
Temp 56
phosphates 50 - 100 (two tests, different results)

The cell has been tested. It is clean. It is generating chlorine while on.

Believe it or not, I sat by the control panel over the course of several days, watching the SWG diagnostics minute by minute. As I stated before, the SWG is operating only the first 24 minutes of each cycle. It never resumes during the cycle. For example, whether the cycle is for 2 hours or 6 hours or 12 hours, it is only on for the first 24 minutes of the first hour only, for 24 minutes total.

It does not appear to be an overheating problem for two reasons:
1. I can manually restart the SWG as soon as it stops
2. I believe the on time would vary
I called tech suppport and was told to reset the system by flipping the circuit breakers off and letting it reset for 4 minutes. Tried this many times over the course of the year, to no avail.

Update: Goldline Tech Support suggested that the cell needs to be replaced. Does this make sense considering it seems to be a timer issue? I don't have much confidence in that suggestion since the cell is generating chlorine.
Thank you for your opinions

If the cell is bad, it shouldn't work at all. If the cell is part of the salinity measurement system (I'm not too familiar with Goldline), it may test OK in forward mode, but fail in reverse, if there is a bad plate. If it measures salinity each time it reverses, that may be the cause if it uses 24 minutes for a cycle time (100% = ON for 24 minutes, 50%= 12 0=0.) In superchlorinate it should still reverse at a specified time, but run continuously for specified time. Goldline should be able to tell you what the specified times are, and if they can be changed.

It sounds more like a control board timer issue to me
Good luck! And Best Wishes!

I appreciate your feedback. Still doing the detective work, but I'm learning a lot.
Update: Goldline tech support today informed me that the system is functioning as it should: When the water temp is between 50 and 60 degrees, the SWG will only be on for the first 24 minutes of a two hour cycle. It is supposed to turn back on in the 3rd hour (for 24 minutes), if the pump is still on at that time. (I'm feeling cheated that this information is nowhere to be found in the manual or online.) My pool water is 58 degrees right now, and I am only running a two hour cycle, hence the 24 minute SWG run time.
If this 24 minute run time continues even after the water warms up, then I'm thinking the water temp sensor is bad. I may try switching it out with the air temp sensor (they're identical). As an aside, maybe there's a way to fool the system into thinking the water is warmer? Will post my findings.

Yes, but thanks for digging this up for the rest of us!

Someone should undertake a book composed of all the "secrets" of how various pool equipment operates such as was done years ago for computer file formats when it seemed no word processing or database file could be read by anyone else's!

Update:
My system is running as it should now that the water temp is in the 60's. The SWG is set at 60%, so it is on for the first 72 minutes of a two hour cycle. It resumes at the start of the third hour.
The chlorine readings are right around 3, so I'm happy about that.
I had two "cell power error" messages, one on the 24th of March, another on the 27th. Each was handled by resetting the breaker. I was told by Goldline that this message indicates that the circuit board would need to be replaced. I'll put that off as long as I can. Has anyone had to replace theirs and what did it cost?

desoto.
you might want to look at this site for info on the cell power problem -http://www.nocellpower.com/

I really like the letter from Loni of Pool Emporium Inc, Servicing Brevard County, Florida!

Good Luck, and Best Wishes!

Thanks for the link to "nocellpower". That is not the error message in my case, but I envy the easy fix. Mine read "cell power error", which is different. Have not had a recurrence of the error message since 24 March (over 3 weeks now). I hope it was a random event.
Currently, things are running well and I'm keeping my fingers crossed.
Thanks to all for your input. I'll post back if the dreaded message returns.

RE: random "cell power error" (NOT "no cell power" - there is a difference!)
I spoke with an electronic engineer who suggested that the randomness of the “cell power error” messages might be explained by a short circuit on the circuit board, due to insects. Thinking back, our control panel was infested with earwigs when the problem first occurred. After eradicating the earwigs, the system was fine all summer.
When the error next occurred, argentine ants had set up housekeeping in the control box. We’ve since evicted them, and everything is fine once again.
So, this may be a good theory for the random occurrence.

I also posted this at:
http://idoneitmyself.wordpress.com/2009 ... /#comments

DO NOT SPEND $$$ ON A NEW CIRCUIT BOARD BEFORE CHECKING FOR INSECTS. IF THEY ARE VISIBLE CRAWLING ANYWHERE OUTSIDE OR INSIDE YOUR CONTROL PANEL BOX, THEY ARE SUSPECT.