Advice on Zodiac Clearwater C170 SWG

[MLML]

G'day folks,

I've read alot on the site and learnt heaps, but now have a problem with my SWG.
A few years back it died - ended up being the bridge wave rectifier. Replaced that, worked fine for a few years.
Now it runs for a few minutes, then blows the fuse. Replace the fuse, blows again.
I bought a 2nd hand unit (controller & transformer) on ebay, swapped the transformer - same problem. Swapped the controller - same problem.

It appears that the cell might be faulty (it's OLD) but I would have thought when the cell goes faulty is would lose it's coating and the current would decrease, however it seems to be an excessive current blowing the fuse.

Any ideas or similar experiences?
Anybody know of where to get a circuit diagram for these units?

Thanks

MLML

 

[y_not]

Welcome to the forum MLML!

You're blowing the fuse because your cell is either drawing too much current, thus exceeding the amperage capacity of the system and blowing the fuse to prevent burn out. Or, something has bridged the cell and is causing a short.

Have you taken the cell out to inspect it?
Odds are that there's corrosion on the plates, this typically decreases draw, but if the corrosion bridges, or gets, very, very close to an adjacent plate, then you could experience the type of behavior that yours is exhibiting.

Another possibility would be some sort of damage to the cell, something came in contact with it and is lodged in there, a screw/bolt is loose on the spacers, etc.... Stranger things have happened, trust me.

Take it out and have a look with a nice high powered flashlight.
Your eyes are your friend!

 

[MLML]

Thanks y_not. I've removed it, inspected it, and given it a good clean with acid, but still the same fault. I was thinking that maybe there could be an insulation breakdown in the wires, but I don't have a insulation tester to test it out properly.
Wish I could find a schematic diagram.......

 

[y_not]

Not sure on where to get one of those, manufacturers are really closed lipped on that sort of thing. Try calling them and asking nicely??

Is there a local dealer or pool store that you can take the cell to and get it tested?

Can you post a pic or URL with pics of the unit you have?
There seem to be a lot of variances in the unit.
Pics inside the control box and of wires, the cell, etc.. would be helpful.

 

[MLML]

Hmm, I might take it out and this weekend and see what pool shops nearby can test it.
Thanks

 

[MLML]

Well, after pulling the unit out last night I have discovered that the power transformer is faulty

Time for a new chlorinator.........

 

[UnderWaterVanya]

Now it runs for a few minutes, then blows the fuse. Replace the fuse, blows again.
I bought a 2nd hand unit (controller & transformer) on ebay, swapped the transformer - same problem. Swapped the controller - same problem.

Well, after pulling the unit out last night I have discovered that the power transformer is faulty

What am I not understanding? Are both transformers bad? Is this part not possible to replace?

 

[y_not]

What am I not understanding? Are both transformers bad? Is this part not possible to replace?

Good catch UWV!!
Yes, I was wondering the exact same thing. Transformers aren't proprietary, it's just a matter of finding one that matches.

A short in the winding of a transformer could easily cause a fuse to blow, that's their job.
If the transformer isn't encased in epoxy, you might disconnect it, pull it out and peel it apart. Check to see if the thermal fuse in the there, soldered to the winding is good. Usually they just blow and then you get nothing, but I could see it being in a state of failure where it shorts the circuit.

Here's some good info: http://www.electronicrepairguide.com/re ... eaker.html
The transformer section is where you want to be in that article, but it's all a good read.

 

[MLML]

Now it runs for a few minutes, then blows the fuse. Replace the fuse, blows again.
I bought a 2nd hand unit (controller & transformer) on ebay, swapped the transformer - same problem. Swapped the controller - same problem.

What am I not understanding? Are both transformers bad? Is this part not possible to replace?

Good catch UWV!!
Yes, I was wondering the exact same thing.

Yes - they are both cactus, one is shorted across on the secondary windings, the other has insulation breakdown on the primary windings.
I wrongly assumed that both transformers weren't faulty when initially tested it out

Transformers aren't proprietary, it's just a matter of finding one that matches.

Your right, however the 9V output isn't a very common O/P voltage here is Australia, and the generic ones I found here that can supply 20+ Amps were almost as expensive as a new power supply unit!

A short in the winding of a transformer could easily cause a fuse to blow, that's their job.

Yep, that's exactly what's happening.

If the transformer isn't encased in epoxy, you might disconnect it, pull it out and peel it apart. Check to see if the thermal fuse in the there, soldered to the winding is good. Usually they just blow and then you get nothing, but I could see it being in a state of failure where it shorts the circuit.

Here's some good info: http://www.electronicrepairguide.com/re ... eaker.html
The transformer section is where you want to be in that article, but it's all a good read.

Thanks for the link. Mine is definitely short circuit and not open circuit.

Since my last post I have found 1 place that sells the original transformer, and at a decent price , so I'll do a bit of fault finding this weekend using some toroidal transformers that I got my hands on

Thanks very much for the replies, appreciate it!