How do you know that your cell needs to be replaced?

[Greg Hughes]

Our cell is about 5 years old. Our pool is open for about 5 months a year and our cell always appears to be clean when inspected. It no longer seems to register the salt level. My dog chewed the wires from the cell to the controller. I spliced them back together. Everything seemed to be working for about a week. Then it started saying to check the salt level and cell. We have done both repeatedly.
Is there a chance that since there are four black and four white wires I could have splice them incorrectly yet still have the unit for about a week? I really don't want to buy another cell unless I know that is the problem. Thanks for your help.

 

[JasonLion]

Welcome to TFP!

The cable between the controller and the cell carries a lot of power at a low voltage and is very sensitive to even slight increases in resistance. Simply connecting everything together with wire nuts would not be enough, you need to solder the connections.

It is also possible that you cell is failing, one of the symptoms is slow salt readings, but that seems less likely.

 

[Greg Hughes]

Is it possible to mix up the black and white wires since there are two pairs to each?

 

[JasonLion]

If there is any logic to their wire coloring (extremely likely) it should be fine as long as you connect white to white and black to black. I assume they are doubling the wires so they can carry more current than a single wire would carry.

 

[Samantha Sabrina]

One set should likely be for the sensor and the other set for the cell itself, so if they used industry standards both white should be common, and then the 2 blacks hot, it could be that you have the 2 black wires crossed, hopefully they were designed and intended to carry the same voltage and current.

I would try swapping the 2 black wires and see if that helps, if so then as Jason stated, solder them, but put heat shrink tubing over each wire first, then when the solder is done slide the tubing over the solder joints and heat the tubing so it shrinks and seals, then tape them if you want.

 

[Greg Hughes]

Thanks for the responses. I tried swapping the black and the white wires. My salt reading still says zero either way. Should it read at least something if it was working? When I had first spliced the wires the cell was recognizing the salt and then after a week or so stopped. I have not soldered them yet and just have them twisted together would that matter to just test them? Any way to know if the cell is bad without spending $500 to buy a new one?

 

[Samantha Sabrina]

Greg,

Just twisting the wires together might work for the sensor, but very doubtful it would work to test the cell, at the very least you need wirenuts on them if for no other reason than safety, (prevent a short, or accidently touching a hot wire).

If the hot wire for the cell was supplying a higher voltage, or a circuit board was supplying the voltage for the sensor, then by mixing the hot wires when you first connected them, it is possible that you may have burned something out, either putting too much power to the sensor itself, or the cell maybe drawing too much current thru the circuit board, there are countless possibilities, and without looking or knowing how it is all supposed to be connected I am only guessing.

So ultimately it could be something as simple as maybe a blown fuse on the controller, a burned out sensor, maybe a burned out power supply inside the controller, and it just gets worse from there.

If you bought it new did you keep all the paperwork for it?

Perhaps get a good electrician to come and have a look, sometimes they have a schematic inside the cover of controllers like that, and if so he could test all the different components and see if it is something simple, or if it is worse than that.

My next best suggestion would be maybe take the sensor out and take it to a pool supply store and see if they have a means to test it and see if it is any good.

It is very doubtful that you damaged the cell itself, but the sensor, back to the circuit board, power supply or even the whole controller..just too many things to pinpoint without looking at it.

 

[Greg Hughes]

Everything seems to work except sensing the salt. If I turn it off and then set it to auto, it starts to generate but then clicks off saying check salt since it is not sensing anything. I can go through the diagnostics and all the different numbers show correctly except for the salt. That is why I don't think it could be a fuse or power source. I guess our next deal should be to take to a shop and have them test the cell as you suggested. Thanks for your help.

 

[Samantha Sabrina]

If the cellis producing at first then stops because it thinks there is not enough salt, then the problem is most likely just the sensor, and that should be replaceable all by itself, (I don't really know since I haven't had one to actually look at yet.

Again, I am not sure but it very well could be that the sensor is just bad, OR the part of the circuit board that is using the sensor input to tell the rest of the system what is going on could be bad, and that could very well be an intermittent blown fuse, (it works until it gets hot then separates, and when you turn it off it cools and makes contact again, and works until it gets hot), I have seen fuses do this many times while working with automation and robotic machinery, (they are a royal pain to track down), but I have also seen solder joint on circuit boards do the same thing.

Power transformers can also act like this, or even a bad connection somewhere.

I suggest you just see if you can remove to sensor and have it tested, or buy a new one and try it, that should most certainly be cheaper than the cell, I am guessing here but I think the sensor would work on the idea of measured resistance, or measured voltage or current, comparing what is sent out versus what returns, and the controller compares the 2 values and decides what the salt level is from that.

If the sensor tests good or a new one does not resolve your problem then I would look at the controller, and I would really find out some how or another which wires go to which wires, one set has to be for the cell and the other for the sensor.

If the sensor is bad, then replace that, and make proper repairs, (solder), the wires, so they are making the best possible connection.

One way to check the cell itself is to turn the SWG off, and run the pump, get a water sample as it comes out into the pool, as close as possible, and test it for CL, then turn the SWG on and take another sample the same way and see if the CL is any higher, if so then you know the cell is good, or if you have a way of getting a water sample before it enters the pool would be even better.

 

[JasonLion]

By far the most likely possibility is that your unsoldered splices have introduced too much resistance in the wires, which the unit is reading as a low salt level. As I said at the start, simple twisted connections will not work in this application.