Is my IC40 working?

[IaMac]

Moved from here.

I'm not sure if I should start a new thread or just continue this one. The latter is generally preferred on most forums, to cut down on searches, so I'll add here until a mod directs otherwise.

Like the OP "I" have an IC40 manufactured in 2014, perhaps retrofitted to a pool installed in 2012. As I am not the original owner I can't say for sure. What I can say is that I'm not sure that the SWG is working. The lights indicate only 20% lifetime used, perhaps 3000 hours but that seems way too low. Then again I have no data on how often the pool was used prior to it changing owners this season.

When the pool was opened (May 15) I inspected the plates and they looked clean. An acid bath produced little bubbling action so I quit that action after a few minutes. Just today I had an opportunity to inspect again and the plates look exactly the same, no flakes. Should I have seen some accumulated "stuff" ? Maybe not, please read on.

Upon opening the pool the SWG operation was erratic with a low salt condition often noted. Checking the salt level (via store and intellichlor diags) showed it a bit on the low side, 2700 ppm. I added the salt needed and it was still erratic. I finally chased this down to a bad thermistor in the unit. For the time being I've bypassed that with a 10k fixed resistor and the unit now runs w/o issue. What I never seem to measure is any chlorine in the pool no matter how long it's been running (initially 20 hrs/day and now 24) nor it's setting (60%, now 100%). The result is presently a green pool, in the process of being recovered, where a week+ ago it looked and measured fine.

So my question is ... Is there some good way to tell if this unit is still working or not ? All the lights are green, the salt is at 3400 ppm and the unit says flow is OK. Can I measure some electrical parameter, current draw for example ? How much chlorine should there be, given the aforementioned setting, in a 27 kgal pool ?

I will mention that the water had tested as balanced with an LSI of 0.0 - 0.1 from 2 different pool agencies. I mention 2 because the installer had been reporting the CYA as 80 and progressing to 125 after using the dichlor shock to get the water good (immediately after opening). Yet my test strips and liquid tests had indicated a level more like 30 ppm. So I went to another tester who confirmed 24 ppm. FWIW the relevant numbers a week ago were :
pH = 7.1
TA = 119
Calcium Hardness = 268
CYA = 24
Salt = 3400 ppm
And 0 levels for copper, iron, etc.

As I am trying to ungreen (algae plus pine pollen plus party) it might be a few days before I can measure chlorine level due to the SWG all by itself but I'd appreciate all answers and opinions as to whether this unit is "pining for the fyords". Also is it necessary to regularly add chlorine, or to shock, a SWG equipped pool ? This is all new to me.

 

[mknauss]

Welcome to the forum!
You answered your own question - you have algae. The SWCG can in no way add enough FC to the pool to get ahead. It is not designed for that.
You need to SLAM Process. To do that, you need a proper test kit - see Test Kits Compared. I suggest the TF100XL from TFTestkits.net

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[Jimrahbe]

Mac.

Salt cells can never produce chlorine faster that algae can consume it... Most likely the cell is working as hard as it can, it just can't keep up.

I suggest that you read our pool school and see how we feel about pool store testing..

The first thing you will need to do is to perform what we call a SLAM... SLAM Process

Our SLAM process is very specific, you have to follow it to the letter if you want it to work..

You will need a test kit that can measure an FC level of 25 to 50 ppm.. I use the TF-100, but the Taylor K-2006C (and yes the C is important) will work as well.

As long as your IC40's "cell" light was on and not flashing, more than likely the cell is working..

Thanks,

Jim R.

 

[IaMac]

I should have mentioned that after "fixing" the thermistor issue and before the algae bloom, the pool was nice and clear and all the measurements looked good ... except for the FC and TC levels. After all the shockings to open the pool, these levels both dropped to < 0.5 ppm despite the SWG running at 60% for 20 hrs/day. I added more chlorine in the way of granular dichlor (per the pool store/installer) to get the FC back up and then increased the SWG % and runtime, both to no effect after several days. I never had good FC levels unless I was manually adding chlorine. I should have made this point clearer above.

The algae seemed to jump in after a pool party and days of heavy winds and rain, where I hadn't manually added chlorine. I also wonder if the huge pollen burst, yellow gunk typical for this time of year hereabouts, aided that.

So I'm not expecting the SWG to clear the pool, I'm presently hyper-chlorinating to solve that problem, which was to be another thread, but I figured root cause first.

So why didn't I measure some reasonable levels of FC prior to the bloom? Unless you think the algae was present, just not visible, since day 1 ? I'd be surprised if that were the case given the multiple shockings that were done prior to the apparent bloom.

 

[mknauss]

'Shockings' do little to algae other than push it back a little. To eradicate algae, you need to SLAM Process. It is a process.
To properly manage your pool water chemistry and to SLAM the pool water you need a proper test kit - see Test Kits Compared
I suggest the TF100XL from TF-100 Test Kit ™

 

[JamesW]

The power usage should be about 170 watts while generating. You can check the amperage of the supply to verify that it's working correctly.

At 240 volts, the current should be about 0.7 amps.

Use a good "true RMS" meter.

During production of chlorine, you should be able to see tiny hydrogen bubbles coming from the returns.

 

[IaMac]

I had a chance to make some electrical measurements. The DC output of the PCB inside the ET4 panel was 25V (red to black wires) with the IC-40 set to superchlorinate. This is in the ange of 25-35 VDC that I've read it's supposed to output. I read a current draw of 4.5A on the red wire. I have no idea of what this is supposed to be other than to go by the wattage given above. A draw of 4.5A at 25VDC is 113W, a bit lower than the 170 above but not nothing either. So I'm still left unconvinced either way (working or dead).

The pool passed it's OCLT so I am letting the FC levels come down with the SWG off. When I get back to the nominal 5 ppm I'll turn the SWG back on and, after a few hours, crack the output coupling until it leaks. I'll collect a sample and test it. I assume it should show abnormally high chlorine levels. Although I can't say what they should be, I expect therm to be at least 2x the water concentration (SWAG).

This leads me to another question that I've not found the answer to. Why is the recommended CYA level higher for SWPs vs fresh water pools? I can put this in the water chemicals forum if needbe.

 

[mknauss]

From - Pool Water Chemistry
Salt Water chlorine Generation (SWG) pools seem to require a higher level of CYA, about 70-80 ppm, to operate efficiently. The theory is that the CYA is slow to "store" the chlorine as it is being generated so without enough CYA there is a build-up of chlorine that degrades the performance of the salt cell. I would prefer that the SWG manufacturers offer a larger lower-power (per length) cell that would work efficiently at lower CYA concentrations.

 

[JamesW]

113 watts is a bit low for an IC40. I would check the wattage of the input.

If the cell amperage drops below a certain amount, it will show a Cell error. If you're not seeing an error light, the cell is probably working correctly.

Cyanuric acid helps protect the chlorine from loss to the sun. The steady input of chlorine works well to sanitize the water even with higher CYA levels.

Cyanuric acid also helps prevent pH rise and scale because it is a form of alkalinity/acidity that does not become carbon dioxide or carbonate in the cell.

The fc rise from before the cell to after the cell depends on the flow rate. At 40 gpm, the fc will be 2.9 ppm higher after the cell.

40 gpm = 57,600 gallons per day with 22.4 oz (1.4 lb.) Chlorine gas added.

Did you look for the tiny hydrogen bubbles coming out of the returns?

 

[IaMac]

113 watts is a bit low for an IC40. I would check the wattage of the input.
...
If the cell amperage drops below a certain
The fc rise from before the cell to after the cell depends on the flow rate. At 40 gpm, the fc will be 2.9 ppm higher after the cell.

40 gpm = 57,600 gallons per day with 22.4 oz (1.4 lb.) Chlorine gas added.

Did you look for the tiny hydrogen bubbles coming out of the returns?

I was able to measure the current draw, but not the voltage, input to the PCB. Getting to a naked set of terminals was non trivial and it was starting to rain.

What I measured was 5.22A. if the input was at it's nominal 30VAC then that's 156W, closer to your expectation. That was with the SWG set to "superchlorinate". Not surprisingly I measured <10mA with the unit set to disabled.

Does that indicate some degraded level of capability ? I guess I'll know for sure in a week, after the FC levels drop enough to do a good upstream/downstream test.

When I looked at a jet I couldn't see any bubbles but I got tired of looking after 60 or so secs.

 

[JamesW]

I was thinking about the high voltage 240 input. The amperage should be about 0.7 amps/

 

[IaMac]

I was thinking about the high voltage 240 input. The amperage should be about 0.7 amps/

I measured that as well, 238VRMS and 0.71ARMS. I thought it less accurate than the aforementioned.

So ... where is my chlorine?

 

[JamesW]

Since the power is going through a transformer, the power factor is probably going to be less than 1.0, which means that the volt-amps will be higher than the actual watts.

You would need a watt-meter to get an actual wattage measurement.

The amps on the dc side should be more accurate if you can get that. They should be in the 6 to 8 amp range depending on the salinity and the water temperature.

The cell measures the current and adjusts the voltage to maintain a consistent amperage.

If the cell cannot maintain the amperage above a specific minimum, the Cell light will not be solid green.

If the cell light is solid green, then the amperage should be above the minimum assuming the amp meter in the cell is accurate.

I suspect that you just need to do a full SLAM and then the cell should be able to keep up.

 

[IaMac]

I suspect that you just need to do a full SLAM and then the cell should be able to keep up.

Just completed the OCLT and have been waiting for residual FC to drop but you've given me an idea. It seems that electrically the cell should be good. While I could wait and do my upstream/downstream test (and probably will anyway), I could remove the cell, seal off one end, fill it with pool water, defeat the flow switch and look for the bubbles you've mentioned. After a few minutes I suspect the cell water would become even more chlorinated, perhaps measurably so. For that matter I could mix up a calibrated solution of tap water plus salt, with no chlorine, and do likewise. That would be easily testable.

Or do I really need flow through the cell, even with the switch bypassed? In that case I suppose I could plumb up a test bucket, attach one end of the cell to the bucket, fill both bucket and cell with my calibrated solution and pump, by hand or otherwise, from the bucket back into the cell input end. Do that for 1 or 5 or X mins and then shutdown and measure the chlorine level in my mini test "pool". If the production rate scales linearly I could even get a guestimate of how it should work in the pool. And also look for bubbling during the test.

If I promise to wear my safety glasses, can I test the bubbles to see if they are bydrogen? I know a sure way to tell.

 

[JamesW]

You can do the test just by filling the cell with water and watch for the bubbles. If it bubbles, the bubbles are hydrogen and chlorine.

Just don't cap both ends as the gas would create a lot of pressure.

It's really not necessary, because the amps are enough to determine that it's working.

It's like if you had a 5.5 kilowatt heater element in a hot tub and you wanted to verify that the element was actually producing heat.

If you measure 240 volts and 22.9 amps, then you know that the element is producing the correct amount of heat because the power usage is correct.

 

[IaMac]

It's really not necessary, because the amps are enough to determine that it's working.

That's pretty much my thinking and why I asked for some type of electrical tests in the OP. Ripping apart a molecule of salt requires some amount of energy, doing that repeatedly means some power draw. If the measured draw is high enough, it can't be due to just running the electronics, some (most) of the draw must be due to producing chlorine. Of course there might, maybe some failure mode that I'm not imagining...

So a quick check for bubbles is easy to do and should settle the question until/unless after I turn the SWG back on, set at some high level for 24/7, and (again) see my chlorine levels drop to zippo. That should play out one way or the other before this weekend.

 

[IaMac]

I have gas!

Perhaps I should rephrase that. The SWG generated bubbles when tested as discussed above. So now it's time to see if it can hold chlorine levels where they need to be.

 

[IaMac]

FWIW the FC and TC levels were down to just above 5 ppm tonight so I turned on the SWG at 70% and the pump with run 24/7 at various speeds. I'll see what the levels are in the coming days.

 

[IaMac]

It seems that my IC40 is working, though I question why I have to set it to 75% and run the pump nearly 24/7 to keep a constant FC level. It's not like I'm in sunny AZ where my daytime chlorine loss would be expected to be high. I've seen other posts where a similarly size pool only runs their IC40 at 40% (pump time unspecified).

So my question now is do these SWGs degrade over time, using the same electrical power input but producing less and less chlorine? Or do they perform at full capacity and then just die, like a good Greek footsoldier running from Marathon? Oh joy to me!

PS- yes the pool passed it's OCLT. I'm thinking I should start a thread asking people to do an overnight chlorine production test (OCPT), where the chlorine level is checked at dusk and again in the AM, but with the SWG left on at X% and the pump running. Let's see what the FC increase is for various sizes pools.

 

[mknauss]

You can certainly do an overnight chlorine production test. Easy to do. And PoolMath (app) will tell you how much FC the IC40 will add over that time.
In your pool, with the IC40 at 100%, it will add 0.3 ppm FC per hour.