IC60 Measuring Salt Level Often

[MyAZPool]

Lastly, at some point, I will know one way or the other what happens (if anything), when one injects 29% MA about 15" in front of an operating IntelliChlor. After a while I will report on the results of said experiment. Let's just hope I am not digging deep to replace an IC-60 cell...
Thanks and apologies if this became a "hijack"...
r.

 

[Dirk]

Jim's explanation certainly makes sense. Of course, that's giving the same engineers that couldn't "IC60-proof" the IpH circuit board connector a lot of credit!! Dang, I wish I could remember where I picked up the notion of the "deadly gas" theory...

 

[Dirk]

Lastly, at some point, I will know one way or the other what happens (if anything), when one injects 29% MA about 15" in front of an operating IntelliChlor.

I also have it in my head that Pentair recommends placing the injector just in front of the IC because the acid-rich water helps keep the IC's plates clean. Not sure where I got that one either!

 

[MyAZPool]

Of course, that's giving the same engineers that couldn't "IC60-proof" the IpH circuit board connector a lot of credit!!

BTW @Dirk Those engineers you refer to got promoted about a year ago. They are the one's responsible for engineering the IntelliCenter and ScreenLogic Alexa Skills.

 

[Dirk]

Does the ScreenLogic Alexa Skills work any better than the IntelliCenter?

You know, they can make a computer that can fit in your pocket. We have the technology!! How hard could it be to make one that can keep your pool squared away!! Priorities!!!

 

[Flying Tivo]

My IC-40/iph combo burned out the connectors. @Dirk , its not that the iph pump and ic combination is drawing too much amps or that the SWG board is not able to keep up. its that the bridge that is made when you plug the ic to the iph box and the iph box to the ET just has too much resistance. Either because its lower rated pins/connectors or the internal wirings is a smaller AWG. Logically the IC-60/iph combo would fail more often since the iph box is the same for all SWG.

In my setup i run the iph pump from the same SWG board on the ET as the IC and at the same time drawing amps and the SWG board and Power supply can handle them just fine. About dosing while the cell is producing i have been doing it for the las 6 months without trouble.

 

[Jimrahbe]

About dosing while the cell is producing i have been doing it for the las 6 months without trouble.

Tivo,

Tell us how you are doing that? As it comes from the factory it can't do that because the cell is told to shut off when the acid is dosing.

Thanks,

Jim R.

 

[Flying Tivo]

Tell us how you are doing that?

Replacement IC-40 flow, temp sensor with aftermarket

Has anybody tried Optimum Pool Technologies for replacement sensors? They are at least half off original parts.

www.troublefreepool.com

 

[MyAZPool]

All,
Frankly, I have had my doubts regarding the opinions or assumptions that the IntelliChlor stops producing chlorine during times of IntellipH dosing. These doubts "were" mostly based on the fact that I was unable to find ANY written reference from Pentair regarding this apparent feature.

I also doubt that the dosing of acid during the times of chlorine production from an IntelliChlor has any negative side-effects to equipment. Again, I can find no documentation that confirms this fact, only speculation and conjecture.

I decided to conduct my own experimentation to see if I could duplicate what @Dirk had observed. He had stated that he observed the IntelliChlor cell temporarily “shut down” production of chlorine when the IntellipH doses acid.

IC60 Measuring Salt Level Often

I can only assume that he noted some type of visual change of status lights on his IntelliChlor Cell Control Panel during this time of IntellipH acid dosing in order to make this claim. I had never observed such an occurrence but that doesn’t mean it didn’t happen with my IntelliChlor. It just means that I did not happen to observe it.

Note: He operates an IC-40 and I operate an IC-60. I wasn't sure if that made a difference or not.

Since my pool water is too cold to allow the IC-60 to produce chlorine (cold water shutoff feature), I cut the white wire between the thermistor in the flow switch assembly and the cell. I did not have to cut the green wire because I have the newer version of the flow switch assembly, so there is no green wire to cut.

Making the IntelliChlor Work in a mild Winter

Intellichlor Internal Salt Level Calculation

I then turned the filter pump on and tested the IntelliChlor and it was on and the “Cold Water – System Off” light was NOT illuminated. All other indicator lights were normal after the IntelliChlor temporary start-up sequence was complete.

Here are the steps that I used to conduct my experiment.

1. Pump and IntelliChlor on.

2. Set sanitizer output to 100% This would cause the cell to produce chlorine for 265 seconds (4.42 min) of each 5-minute period.

3. Set IntelliChlor to "Boost" or “Super Chlorinate".


4. I set the IntellipH dosing amount to 100% (60 second dosing event once each hour). I then observed on the IntellipH controller screen that automatic dosing would occur in 60 minutes. I came back in 55 minutes and I waited.


Once automatic acid dosing began (the IntellipH first indicates “CHECKING CELL” before power is delivered to the peristaltic pump). I then observed the IntelliChlor Cell Control Panel for ANY indication that chlorine production was being stopped/halted.


The sanitizer output lights ALL went OFF and the CELL Status light was NOT illuminated, during the time period that acid dosing was taking place. They immediately came back on at the termination of acid dosing.


4. Next, I waited 5 minutes and performed an IntellipH manual dosing. Manual dosing’s always run for 60 seconds. Once again, the same exact result.

Summary. I can confirm the following fact: THE INTELLICHLOR INDICATES NO CHLORINE OUTPUT DURING THE TIME OF INTELLIPH ACID DOSING! Based on my experimentation as noted above.

Am I stating empirically, that chlorine production is halted by IntelliChlor during times of IntellipH acid dosing? Nope. I have no way of proving that. However, ALL of the output lights AND the CELL STATUS light cease to be illuminated during acid dosing. That’s good enough for me!

I would welcome anyone to disprove my belief now that an IC-60 (non-commercial model (i.e., CIC60P), IntelliChlor does in fact halt chlorine production, during times of IntellipH acid dosing (automatic or manual mode).

Pentair MUST have a reason for this. However, I still cannot find any substantial “proof” that the dosing of normal pool-type muriatic acid during times of IntelliChlor chlorine production causes any damage to equipment.

I am still of the belief that an IntelliChlor cannot produce enough chlorine in a solution of running water with a pH of approximately 7.6ppm to produce enough chlorine gas buildup to produce any ill side-effects to the equipment.

Information that I have found suggests that the IntelliChlor IC-60 (in boost/super chlorinate mode), can produce approximately two pounds of chlorine in 24 hours running at boost. That will raise the chlorine level approximately 2ppm for 1 million pounds of water or approximately ~10ppm in 20,000 gallons over 24 hours.

However, in real-world operations, the IntelliChlor isn't converting anywhere near that in most cases.

The IntelliChlor cell is designed to operate at a flow rate of 25gpm +/- 5gpm.
That means that if one is running at boost with the chlorinator, then the worst that could happen is the adding of 0.001 ppm of chlorine to a gallon of water in one minute.
Contrast that to WWI, where chlorine gas used in combat was approximately 600ppm, and which would incapacitate and eventually kill in 30 minutes.

r.

 

[Dirk]

Am I gonna need an attorney?

I would say the Cell LED indicator is as important to note as the Output LEDs, if not more so. When that Cell LED is off, chlorine is not being produced, period. I don't know why Pentair also sets the Output LEDs to "none." Might just be a byproduct of the way they are shutting down the chlorine production circuitry within the IC.

And my theory of what I may or may not remember correctly reading somewhere, doesn't have anything to do with equipment damage. I have been saying the IC shuts down during acid injection so that the acid and the chlorine don't mix together on their way to the pool. Maybe @JoyfulNoise can remind us what gas is produced when Muriatic acid is mixed with chlorine. Is it chlorine gas? And isn't chlorine gas reeeheeally bad (poisonous) for humans? Like weapons-grade bad?

Stay with me. Other than their recommended instructions set, Pentair has no way to control the installation positions of an IC and an IpH injector, relative to each other, and more importantly relative to the pool. I recall that the IpH installation instructions recommend placing the injector in the pipe that feeds the IC. They don't specify how far apart the two should be. And I don't recall any instructions in the IC manual about how far the outlet of an IC should be away from a pool return. Which means Pentair would, should, have to consider the possibility that the IpH injector could be installed very close to the IC inlet, and that the IC outlet could be installed very close to a pool return. I see that as a real possibility for a AG pool, where the equipment pad is right next to the pool.

Pentair is very aware of the danger of producing chlorine gas within the IC without water flow. They have two safeguards for that. The built in flow sensor AND the manual which clearly states to wire the IC to the pump circuit. It would follow that Pentair would be equally worried about acid and chlorine mixing together.

My IC is about 30' from the closest return in my pool. Yet I regularly observe hydrogen gas bubbles coming out of not only that return, but a second return about another 20' away. So that tells me gas generated by my IC makes it all the way to my pool, undissolved, in all that water, 50' away!! Now how or if hydrogen gets dissolved in water is surely different than how or if the poison gas formed by mixing MA and LC does, but I still contend some of that poisonous gas could reach the pool, under the right conditions. Those conditions would be the injector being installed close to the IC, and IC outlet being installed very close to the pool. Again, maybe JoyfulNoise can weigh in on this possibility. But regardless of what Matt thinks, it's possible that Pentair thinks this could be a problem, and so they eliminate that possibility, or more likely the liability of that possibility, by shutting down the IC during injection so that can't happen.

Now this theory makes sense to me, so much so that it's possible that I cooked all this up myself, because it seems so obvious. And if that's the case, I plead the 5th!

 

[Dirk]

The following proves nothing, but possibly explains why r and I can't find any documentation on this. If a Pentair employee brought a draft version of a brochure or owner manual or webpage edit to Pentair Marketing or Sales, with a proud product feature list that included a claim that an IntellipH automatically halts chlorine production within its companion IntelliChlor to avoid the production of deadly chlorine gas... it would promptly get deleted, and the author would probably get taken out back for "a chat."

And if the real reason is more inline with Jim's theory, that the shutdown happens because the power supply is inadequate, that too wouldn't make it in front of the public. Pentair, like any other corporation, has plenty of reasons to avoid full disclosure to the public about their equipment, now it works and what it does or doesn't do.

If documentation about this feature doesn't exist, Pentair has as good a reason to hide it as it does to include the feature.

 

[ajw22]

Only us TFP pool nerds would care.

I added your findings to the IntelllipH wiki - Pentair Intelliph - Further Reading

 

[Dirk]

Oh r, before I forget this important point... TOLD YA SO!

 

[MyAZPool]

Am I gonna need an attorney?

Lol....An attorney? Probably not. A publisher? - Maybe

I would say the Cell LED indicator is as important to note as the Output LEDs, if not more so. When that Cell LED is off, chlorine is not being produced, period. I don't know why Pentair also sets the Output LEDs to "none." Might just be a byproduct of the way they are shutting down the chlorine production circuitry within the IC.

Agreed 100%...

And my theory of what I may or may not remember correctly reading somewhere, doesn't have anything to do with equipment damage. I have been saying the IC shuts down during acid injection so that the acid and the chlorine don't mix together on their way to the pool. Maybe @JoyfulNoise can remind us what gas is produced when Muriatic acid is mixed with chlorine. Is it chlorine gas? And isn't chlorine gas reeeheeally bad (poisonous) for humans? Like weapons-grade bad?

Stay with me. Other than their recommended instructions set, Pentair has no way to control the installation positions of an IC and an IpH injector, relative to each other, and more importantly relative to the pool. I recall that the IpH installation instructions recommend placing the injector in the pipe that feeds the IC. They don't specify how far apart the two should be. And I don't recall any instructions in the IC manual about how far the outlet of an IC should be away from a pool return. Which means Pentair would, should, have to consider the possibility that the IpH injector could be installed very close to the IC inlet, and that the IC outlet could be installed very close to a pool return. I see that as a real possibility for a AG pool, where the equipment pad is right next to the pool.

Pentair is very aware of the danger of producing chlorine gas within the IC without water flow. They have two safeguards for that. The built in flow sensor AND the manual which clearly states to wire the IC to the pump circuit. It would follow that Pentair would be equally worried about acid and chlorine mixing together.

My IC is about 30' from the closest return in my pool. Yet I regularly observe hydrogen gas bubbles coming out of not only that return, but a second return about another 20' away. So that tells me gas generated by my IC makes it all the way to my pool, undissolved, in all that water, 50' away!! Now how or if hydrogen gets dissolved in water is surely different than how or if the poison gas formed by mixing MA and LC does, but I still contend some of that poisonous gas could reach the pool, under the right conditions. Those conditions would be the injector being installed close to the IC, and IC outlet being installed very close to the pool. Again, maybe JoyfulNoise can weigh in on this possibility. But regardless of what Matt thinks, it's possible that Pentair thinks this could be a problem, and so they eliminate that possibility, or more likely the liability of that possibility, by shutting down the IC during injection so that can't happen.

Now this theory makes sense to me, so much so that it's possible that I cooked all this up myself, because it seems so obvious. And if that's the case, I plead the 5th!

I have proven that the IC shuts down production of chlorine during the time that the IntellipH doses acid. That's pretty much a done deal.

As far as "chlorine gas", possibly being produced, well I may just take a wait and see approach in order to gain as much insight as I can from any facts that may be presented. The opinions that I have obtained so far have resulted in my doubts that nothing bad happens when 29% MA (or less), is introduced into water a foot or two prior to the IntelliChlor and that water is flowing at a rate of 25gpm or more.

Don't get me wrong, there is nothing wrong with erring on the side of conservatism when it comes to possible danger and especially in the absence of any "proof". Heck, I find myself doing that more and more now as my total airframe hours continue to accumulate.
I'm just not yet convinced.
r.
p.s. Apologies for doubting that the cell no longer operates normally during IntellipH dosing. That's just my "trust but verify" nature, getting in the way I'm afraid. But now it's validated..

 

[Dirk]

Lol....An attorney? Probably not. A publisher? - Maybe



Agreed 100%...


I have proven that the IC shuts down production of chlorine during the time that the IntellipH doses acid. That's pretty much a done deal.

As far as "chlorine gas", possibly being produced, well I may just take a wait and see approach in order to gain as much insight as I can from any facts that may be presented. The opinions that I have obtained so far have resulted in my doubts that nothing bad happens when 29% MA (or less), is introduced into water a foot or two prior to the IntelliChlor and that water is flowing at a rate of 25gpm or more.

Don't get me wrong, there is nothing wrong with erring on the side of conservatism when it comes to possible danger and especially in the absence of any "proof". Heck, I find myself doing that more and more now as my total airframe hours continue to accumulate.
I'm just not yet convinced.
r.
p.s. Apologies for doubting that the cell no longer operates normally during IntellipH dosing. That's just my "trust but verify" nature, getting in the way I'm afraid. But now it's validated..

I think that however you set up your acid injection that IF you could even make any quantity of poisonous gas, that it likely would be rendered harmless by the water in the pipe or the pool or the distance between the SWG and the return. I suspect an engineer (or the legal dept) at Pentair caught wind of this vague possibility and brought up the need for this feature just to play it safe. Either for the gas theory or Jim's current theory.

We'll probably never know. I'm glad it's there nonetheless.

I appreciated your experiment. I've done way more to learn way less!!

 

[Dirk]

That said, here's another wrench in the works. Probably need @JoyfulNoise to weigh in on this notion too. So Matt:
- What kind of gas is created by mixing MA and the kind of chlorine produced by a Pentair SWG?
- How dangerous would it be?
- Would it remain in gaseous form, or dissolve in the water?
- Would it become inert by the time it traveled in a PVC pipe from the SWG to the pool?
- Or could it still be dangerous to a person hanging out right next to the return from which the gas exits?

And this new notion, a possible reason Pentair felt they needed to shutdown the SWG as acid is being injected into the plumbing:
- Would very low pH water (formed by injecting high-strength MA a few inches in front of the inlet of an active SWG) interfere with the chlorine-producing process between the plates of an SWG?

 

[JoyfulNoise]

Ok @Dirk time to sloooooow down and take a deep breath and step away from the keyboard, you've used up your allotted words for the day...if you have a brown paper bag then please grab it, put it over your nose & mouth and breath slowly into and out of the bag....if you need low lights and Gregorian chants, feel free to play those in the background. Then, when your pulse rate has returned to normal, read on.

Your SWG, all SWG's, produce chlorine gas at the anode (along with some hydrogen gas as well). There is nothing magical or dangerous about it unless you knowingly and intentionally disable the safety precautions. Chlorine gas is both highly soluble in water (it has a large Henry's Law constant) AND it undergoes chemical hydrolysis whereby it reacts with water to form hypochlorous acid (HOCl) and hypochlorite anion (OCl-). The amount of HOCl/OCl- is dictated by pH. At a pH below 7.5, you get more HOCl than OCl-, at a pH above 7.5 you get more OCl- than HOCl. HOCl is the "good stuff" that oxidizes bather waste and kills pathogens. OCl- is the loser-molecule that doesn't do a whole lot but eventually gets off it's lazy rear end and kills some stuff....when it feels like it. You might know some teenagers with similar attitudes.

Now, as far as acid injection goes, there is a slightly more complicated process involved. I'll attempt to keep it high level so as to not get too far down into the chemistry weeds. There are actually three forms of chlorine in water with two acid dissociation constants. Above we talked about the pK_a2 of chlorine being 7.5 where chlorine either forms HOCl or OCl-. However, there is a first acid dissociation constant, pK_a1 for chlorine and it is approximately around 2 (depends on some other chemical parameters but 2 is good enough). When the pH of a chlorine/water mixture gets near a value of 2, the two major species are hypochlorous acid (HOCl) and chlorine gas (Cl₂) where the chlorine gas will make up 50% or more of the total amount of chlorine in the water below a pH of 2.0. There is an additional issue that when the pH is below 2 and the concentration of chlorine is large enough, the chlorine gas will exist as both dissolved chlorine gas AND bubbles of chlorine gas. The further below 2.0 you go, the more chlorine gas is formed AND the concentration of undissolved chlorine gas increases as pH decreases. This is why if you add muriatic acid to bleach, the sudden drop in pH causes all of the chlorine to want to form chlorine gas AND the chlorine gas comes out of solution as gas bubbles.

So why should an SWG turn off when acid is being injected? Well, again it's a little complicated but there are two very good reasons to do so. The first is based on the chemistry above. You really don't when to run a chlorine generator in a low pH environment or else all you will do is create a lot of undissolved chlorine gas that will bubble out of your returns. Chlorine gas leaving the water will cause the pH to skyrocket and this is what is termed as the "short pipe effect". The other MORE IMPORTANT reason to not inject a strong mineral acid while generating is that you will strip off the transition metal catalyst from the plates by doing so. The TM catalyst normally forms a conductive oxide layer on it's surface that allows it to aid in the formation of chlorine gas. Acids will strip away that oxide which is why I always suggest to NOT use strong acids to clean the cell. However, when the cell is running, the anode will continuously regenerate that TM oxide layer from the freshly exposed TM so, in effect, a constant stream of highly acidic water will continuously strip away the catalyst layer when the cell is electrochemically generating chlorine. Normal pool water at a pH in the 7's does not do this or does so at such a low rate that you would have a hard time measuring it. Drop the pH while the cell is running and you will increase that dissolution rate rapidly and completely hose your SWG plates.

So, there you go, now you have your answer.

Oh, and by the way, chlorine gas makes a TERRIBLE chemical weapon. It's too heavy relative to air and it reacts too quickly with organic matter to be of any use on a battlefield. Mustard gas, which is often confused with chlorine gas, is a completely different substance designed to inflict maximum pain and suffering to those that inhale it. But fear not, your SWG does not produce mustard gas...

 

[MyAZPool]

@JoyfulNoise
Matt... Outstanding and thanks so much. Your two reasons for wanting to stop the IntelliChlor from producing chlorine at the same time that acid dosing is occuring makes perfect sense.

And the timing is perfect.... Because we just figured out how chlorine production from IntelliChlor immediately stops during IntellipH acid dosing and resumes once that dosing has ceased.
It's so simple, even a caveman would be embarrassed.

There is a relay (signal relay module) on the IntelliPh controller board. The very second MA dosing is about to begin, it appears that NC relay is opened which completely interrupts the RS-485 signals from the OCP to the IntelliChlor. Once that signal is interrupted, chlorine production goes to zero and the cell status light goes out. No chlorine production can occur when comms between the OCP and the IntelliChlor are interrupted.

I will validate this fact tomorrow. Since all of my connections at the pad are via terminal boards, It's as simple as yanking the d+ and d- RS-485 conductors (white/green) that connect between the IpH to the IntelliChlor. If the same thing happens, I will have confirmed this fact. There is no RS-485 comms between IntelliChlor and IpH or between Iph and the OCP per se. Only an interrupter relay right there in the middle.

EDIT: Today, I attempted to validate the theory that the relay on the IntellipH controller board was merely disconnecting the two RS-485 connections to the IntelliChlor. Nope. Seems to be more to it. Now it appears that there is a a RS485 transceiver (U5 chip), on the IpH controller board. Looks like that relay interrupts comms to the OCP. Then the RS485 transceiver on the IpH board takes over and issues the appropriate "SetControl" and "SetOutput" commands to the IntelliChlor. This would forcibly turn the IntelliChlor off and disable its controls. Once acid dosing has completed, the DPDT relay closes and allows comms once again between the OCP and the Intellichlor and the U5 chip RS-485 transceiver jumps out of the way.

Then I should be able to recreate the same scenario using a 3rd party signal relay module.
Thanks to everybody that has weighed in here. It's all been very helpful to me, that's for sure...
r.

 

[Dirk]

Thanks so much Matt! So there is a good reason not to inject acid while an SWG is active. But I was way off on the why (though I eventually got close-ish).

- Would very low pH water (formed by injecting high-strength MA a few inches in front of the inlet of an active SWG) interfere with the chlorine-producing process between the plates of an SWG?

I'll use an EasyTouch relay to run my IpH pump in the <52° season (SWG unplugged), but switch back to the IpH controller the rest of the year (when SWG is online).

r, keep us posted on how you make out with the pH sensing/dosing system you're working on!

 

[Dirk]

@JoyfulNoise
Matt... Outstanding and thanks so much. Your two reasons for wanting to stop the IntelliChlor from producing chlorine at the same time that acid dosing is occuring makes perfect sense.

And the timing is perfect.... Because we just figured out how chlorine production from IntelliChlor immediately stops during IntellipH acid dosing and resumes once that dosing has ceased.
It's so simple, even a caveman would be embarrassed.

There is a relay (signal relay module) on the IntelliPh controller board. The very second MA dosing is about to begin, it appears that NC relay is opened which completely interrupts the RS-485 signals from the OCP to the IntelliChlor. Once that signal is interrupted, chlorine production goes to zero and the cell status light goes out. No chlorine production can occur when comms between the OCP and the IntelliChlor are interrupted.

I will validate this fact tomorrow. Since all of my connections at the pad are via terminal boards, It's as simple as yanking the d+ and d- RS-485 conductors (white/green) that connect between the IpH to the IntelliChlor. If the same thing happens, I will have confirmed this fact. There is no RS-485 comms between IntelliChlor and IpH or between Iph and the OCP per se. Only an interrupter relay right there in the middle.

EDIT: Today, I attempted to validate the theory that the relay on the IntellipH controller board was merely disconnecting the two RS-485 connections to the IntelliChlor. Nope. Seems to be more to it. Now it appears that there is a a RS485 transceiver (U5 chip), on the IpH controller board. Looks like that relay interrupts comms to the OCP. Then the RS485 transceiver on the IpH board takes over and issues the appropriate "SetControl" and "SetOutput" commands to the IntelliChlor. This would forcibly turn the IntelliChlor off and disable its controls. Once acid dosing has completed, the DPDT relay closes and allows comms once again between the OCP and the Intellichlor and the U5 chip RS-485 transceiver jumps out of the way.

Then I should be able to recreate the same scenario using a 3rd party signal relay module.
Thanks to everybody that has weighed in here. It's all been very helpful to me, that's for sure...
r.

That's interesting. First, what is "OCP?"

The IpH doesn't communicate with the pool automation controller (IntelliCenter or EasyTouch), but if the automation controller (AC) calls for zero SWG output, the IpH interprets that, by shutting down acid injection. Pentair calls that a safety feature. Also, if an AC is present, the IpH doesn't control the output settings of the IC, the AC does. With no AC, the IpH controls the output settings of the IC.

So I guess when the IpH starts its run, it disconnects the IC from the AC (or otherwise intercepts the communication, perhaps that's what the IpH relay you referred to is doing) and sets the IC output to zero. But then it must ignore this zero setting (which would otherwise shutdown acid injection) and inject anyway.

No point to that, just adding to the info...