EcoMatic Salt cell Works at one polarity, not the other...

[diypoolguy]

First time poster...

We moved into a house last summer and I am in the process of getting the pool squared away and have everything humming except for the SWG. It is a Ecomatic ESC-36 that looks to have several years on it. It is from the Monarch days. Cable looks to be in good order.

Salt level is at 4700 based on salt strip and pool store readings. All the other levels in the pool look fine based on my test strips and taking water in to the local pool store. I've had to supplement with liquid chlorine due to the issue outlined below.

The issue is that, the SWG works at 100% if it is turned on at one polarity, when it switches polarity, it will reduce down to a number lesser than 100%, usually around 45%, then go one LED red, then two.

If I turn it off, switch the leads, turn it back on, it will go back up to 100% and begin producing chlorine.

If I do the opposite, have it run at 100%, turn off, switch leads, turn on, it will run at the 45% go one green then two at which point it is no longer generating chlorine.

I've taken the cell out, inspected it and cleaned it. It doesn't look new by any stretch but is free of scaling and erosion of the plates.

My questions to the experts is, does this seem indicative of a bad cell, or does it seem like something in the unit itself?

Any further analysis I can do to isolate the problem?

Thanks in advance.

 

[JasonLion]

Most likely that is a bad reversing relay in the control unit. {EDIT}Turns out I was wrong, see below.{/EDIT}

 

[diypoolguy]

Thanks Jason. Is that a user replaceable part & if so, where might I find a replacement part?

 

[JasonLion]

I'm not sure how the Ecomatic is setup internally, but usually that means replacing the main board.

 

[Poolsean]

As it's a few years old, it may be the cell as well. On most units, if it provides a reverse polarity function, it does not have a memory as to which direction it's suppose to run in.
It's possible, therefore, for the cell to run in one direction more than the other, thus the uneven wear on the cell to where you're getting the lower output in one direction only.

If it's the relay, you can verify by testing the cell terminals connections. The cell should have the terminal lugs accessible on the cell. Make sure you test the same positions with the same color multimeter probes. After it is suppose to reverse polarity, test the same position with the same color probe to see if the voltage reversed polarity. If the voltage changed, the relay is good and it's most likely a failed cell.

 

[diypoolguy]

Thanks Sean,

I'll try that this weekend and post what I find.

I suppose there is not an easy way to program the unit to not reverse polarity is there?

At least that way I could use up the cell completely before having to buy a replacement.

 

[Strannik]

If the voltage changed, the relay is good and it's most likely a failed cell.

it depends on how it has changed.

if it went up - then most likely faulty cell

if it went down - either faulty relay (by the way not sure if those have relays or SCRs) or a unit doesn't have current control, in which case it can be also a faulty cell.

 

[diypoolguy]

Ok,

I've now checked with my multimeter.

When producing at 100%: 28.7 volts

When polarity is reversed - producing at ~50-60%: 31.5 volts

Thoughts?

 

[Strannik]

looks like half of the cell is dying

 

[Poolsean]

Did the polarity change as well?

If you tested the cell terminals before and after the reverse polarity, you should have gone from a positive voltage to a negative voltage (or vice versa). Make sure you use the same probe (red and black) to the same cell terminals on both tests.
If the polarity did not change, the control unit did not change polarity and I would predict that the circuit board is at fault.

If the polarity changed, the cell is failed in one side/direction.

 

[Strannik]

if it was a faulty board he would've seen a drop in voltage, rather than increase.

 

[Poolsean]

If there's a relay used to reverse polarity and the contact points are oxidized or there's corrosion to increase resistance, there would be an increase in voltage, rather than a drop. However, verifying if the polarity changed direction would confirm it for sure.

If you can reverse the cell cord onto the cell, test the voltage, again with the same probes to the same terminals, the voltage polarity

I tend to agree that the cell is most likely worn out, but it doesn't hurt to ensure that the unit is reversing polarity correctly too. If it is not, then it will just wear out the replacement cell prematurely.

 

[Strannik]

true, always good to check

 

[diypoolguy]

Thanks for all the advice guys.

We can eliminate the possibility of corrosion as I've cleaned the cell and the terminals.

When I initially checked the voltage I switched the terminals but used the same probe on the same terminal.

This morning I measured the polarity and the voltage when it was producing at 100%. By the time I get home it will have switched polarity and shut itself off. I will restart and check the polarity and voltage and post them here.

Thanks Again for your expertise!

 

[diypoolguy]

Ok,

I started by having the unit produce at 100%. Actually, it was producing at 91%. Polarity +. 30.0v.

The unit reversed polarity which of course results in shutting itself down. i reset power. It was producing at 41%. Polarity -. 31.2v.

 

[Strannik]

i would open it and see if you can see anything burnt inside
you could even post some pics here

 

[diypoolguy]

Thanks to one and all for the advice. Unfortunately things seemed to get worse with the cell not working on either polarity. In my search for a replacement cell I found a great deal on a new Autoclear plus with one new cell for less than a replacement cell for the ecomatic. Had to reduce the salt in the pool over the last couple days. Installed today and so far, so good.

One interesting thing on the ecomatic, I assumed by the wire going to it that it was 120v. It was actually 220v. The wire was no more than the size of your avg extension cord. Maybe that had something to do with it...

Thanks again.

 

[Bama Rambler]

Just a note. Wire size has nothing to do with voltage. Insulation does but for the most part, most common wire insulation is rated for 600 volts. Actually since current is the predominate sizing factor for conductors, 220 volt service would have smaller wire than 120 volt service for the same power.

 

[brice789]

I'm having the exact same problem. This is my second module and it happened both times because I let the pH get too high for too long and I probably ruined the module by cleaning it. My unit says that the salt should be above 3,000 ppm but I hear that the unit should really be running at 4,000+ ppm. I bought a new third module, but am trying to run the one I have now on winter mode in an attempt to get a few more months out of it. I hope I didn't just waste $380 because I'm not really sure what I'm doing. The original module lasted almost 3 years. This one only a year. Both were from the OEM. The new one is from Compupool. We'll see how the generic works. It has a 2 year warranty. I've become vigilant about perfect water chemistry these days. The only anomaly is my phosphate levels are 400 and I'm using phosfree in an attempt to bring them down to 100. My cyanuric acid levels are high. I'm not sure if that has any effect. If I need a new system I may go with the Pentair rated at 60,000 gallons (my pool is just under 50,000). I'm hoping the SWG is as good as their pumps. I'm glad to have found this site!