boat A/C trips breaker

[Sean B]

I have a Bertram factory original 1987 era CruiseAir/Dometic split system A/C.

I know just enough about air conditioners to be dangerous, so here is my question. Recently mine will trip the breaker every time the compressor is triggered to come on. The fans run, the water pump runs, the compressor tries to go for half a second, then CLICK.

My first instinct is to replace both capacitors, run and start, and the relay too. I know I probably only need the start capacitor, but I figure while I'm in that little box, I'll freshen them all up.

Sound like the right thing?
Or should I go try whacking the compressor with a hammer first?
(not necessarily a joke, I have heard of this working)

[Navatech]

My first instinct is to replace both capacitors, run and start, and the relay too. I know I probably only need the start capacitor, but I figure while I'm in that little box, I'll freshen them all up.

"Use the Force, Luke"... It's pretty basic as well as pretty cheap to follow your first instinct... Even if your compressor will start with a little "love poke" that would be a sign that it's going to die pretty soon...

[Sean B]

Thanks... what I'm really interested in is whether those in the know think that I'm wasting (or not wasting) my time swapping out components on a 27 year-old boat A/C system, trying to get the old contraption moving again

[RAWicklund]

Sean, there are various ways to free a stuck compressor. Hard start kit, reversing motor, hi voltage surge and that big hammer thing. Since your breaker is tripping before the over current protection on the compressor trips.... Your breaker may be a problem also.

The cheapest way for me would be to test caps then put hard start cap in. Once it frees up then put in new capacitors..... I would leave the relay alone only due to higher cost and I've rarely seen them fail when used on ice machines and small refrigeration units..... That might be different for a marine environment .... I've only worked on a half dozen marine AC's.

Not sure what it is with today's capacitors...... Their lifespan is a fraction of their older relatives....cheap manufacturing I guess...but all brands are the same.

Good luck

Ray

[Charlie J]

I was going to say the breaker could be on its way out

[Sean B]

Hmm I hadn't thought of the breaker. I think I will try that first.

Thank you gentlemen. The formidable b31 board strikes again !

[Navatech]

what I'm really interested in is whether those in the know think that I'm wasting (or not wasting) my time swapping out components on a 27 year-old boat A/C system, trying to get the old contraption moving again

Refrigeration units are really quite simple... Not that many moving parts... It's usually something electrical that goes bad... The one reason why compressors don't get replaced that much today is that the appliances are so cheap new out of the box that once you have added up the cost of labor, parts and material you're pretty close to the price of a new unit... Of course, the "marine" units are more expensive so replacing a compressor might still be a viable option...

Having said that, and considering that your unit is 27 year old your biggest issue in trying to replace just the compressor would be finding a suitable compressor (due to lubrication issues compressors are matched to specific refrigerants) and recharging the system with refrigerant... Back then everybody used some type of "Freon" (R-11, R-12 etc)... However, due to ozone depletion potential and global warming potential these earlier refrigerants were phased out... Considering this is the case you might have to purchase a complete unit just because you'll be unable to find the older stuff...

[Keith Poe]

Swap the breaker with another one or swap the wires.

Turn the breaker off and move the motor by hands see if it's tight.

Guy I rebuilt a 250 ton chiller with lost his fingers to a carrier unit they put them back on with limited use.