A/C Tech support required ...

[electricaldoctor]

My fwd 12,000 BTU "Marine Air Systems" a/c unit was working great this Thursday & Friday, but started to act up yesterday & today. It was kicking out 58* air and was doing a great job in these hi temp days. Everything is clean and there appears to be great water flow. When I start it up, the ammeter sits around 12 amps for about 2 minutes and then it will either trip it's breaker without any further rise in amperage or, other times, the amperage will surge up to 30 amps and then trip it's breaker.

HELP!! Ken

[mainstream]

Possible failIng compressor winding or start run capacitor something is causing an excessive draw on circuit

[electricaldoctor]

screens, filters & strainer are all very clean. Not so sure about the intake screen below the bottom of the boat though. I will check that next w/e. Before I check any further into potential electrical problems, I have broken up a chlorine puck and put it into my strainer and will run it that way for a week with the aft A/C unit running. The outflow for the fwd unit is always way less than the aft unit, but it seems even less than usual. I am hoping that the chlorine might clean up that water circuit and cure the problem. It sounds like a long shot, but I've got nothing to lose while we are away from the boat for the week.

Thanx for your input mainstream.

~Ken

[Old Vet]

sorry to say Ken....but it sounds like you're compressor is toast. :-(

you may want to get a tech in to confirm that....but it sounds like it to me.

[PlayDate]

Ken,

While it is likely to be the compressor, the breaker has an issue. The breaker tripping without a rise in amps usually means the breaker is bad and needs to be replaced. It is a far less expensive exercise and will at least eliminate the false tripping. In at least two cases that I can recall, replacing the breaker actually solved the problem you have been having.

-John

[electricaldoctor]

Well, I am happy to report that putting the broken up chlorine puck in my A/C pump's strainer has solved the problem. It was as I suspected in that the water flow increased tremendously and the unit no longer trips the breaker. The discharge air now cools down to 53*
Cheap fix!!

[Pietro]

Well, I am happy to report that putting the broken up chlorine puck in my A/C pump's strainer has solved the problem. It was as I suspected in that the water flow increased tremendously and the unit no longer trips the breaker. The discharge air now cools down to 53*
Cheap fix!!

Good to know you solved the problem! I'm experiencing a similar problem on my fwd. A/C with the breaker tripping sometimes... specially when power comes from the generator...

I'll check water flow and the breaker, then.

One question: Is the chlorin puck the one for swimming pools?

[electricaldoctor]

That is the same swimming pool chlorine puck that I used Pietro. It was too big for my strainer, so I just broke it up into smaller chunks. I left the rear unit run all week and it got rid of what ever obstruction that was in there. Keep in mind that my boating is in fresh water. You may have to take more drastic measures to clean out your AC lines. There are some threads all about this cleaning process for you salties. I think that they used some sort of mild acid solution. Good luck.
~Ken

[Old Vet]

That's good news Ken....glad you got away with such a cheap fix. As I'm sure you know....a/c techs don't come cheap.

Never having worked on any marine a/c systems.....I'm really curious about what exactly was going on with yours. I'm a little puzzled by what exactly was causing that erratic high amperage draw.

On water cooled systems....low water flow will usually cause a high head pressure in the compressor. Higher amperage draw could come with this....but why your amperage draws were erratic....sometimes holding at 12 then tripping the breaker....other times surging to 30 amps then tripping seems a little curious.

If anyone knows exactly what was going on here....I'd appreciate hearing it.

[electricaldoctor]

It's a mystery for sure and perhaps I may still have a problem. I ran it for several hours yesterday without any problems. I left it running when I left for home yesterday and I will know more when I return to the boat this Thursday morning.
Stay tuned ~ Ken