Coleman Roof AC Help.. Sat upside down, now won't work!

[BoxerPitMix]

Did a few searches here & on Google, didn't come up with much... Sorry if I missed a similar topic that someone previously has posted.

In my search for a good used roof mount AC for my horse trailer's LQ, I scored a heck of a deal on a nice used Coleman Mach (7333C881 Model) with heat strip & perfect shroud cover for $100.

Brought it home, tested it and let it run for over an hour, worked perfectly.

I sat it in my garage floor for about 2 weeks until I had time to mess with it. During that time a coworker came by for me troubleshoot a problem on his car. While helping me clear a few things in my garage to make room for him to pull in, I didn't realize he had slid my AC unit off to the side... and turned it UPSIDE DOWN where it sat for around 4-5 days until I installed it.

I've worked in the RV industry for a few years - and know to keep them upright or at least on their side. Honestly for why - I'm not sure. I can to do leak repairs/recharge on car AC systems, but this is a new animal to me.

So I installed the unit on my trailer last weekend, plugged it in... And on Low or High Cool the compressor will kick in for about 10 seconds, spit out a little bit of cold air, then kick the breaker of whatever it's plugged into. :S

So did it ruin the compressor by somehow filling it with oil or something? I'm really bummed out and hope this didn't toast my unit. 😞

[BoxerPitMix]

Afraid no converter... I'm just now beginning to rough in the interior. Just a line ran straight out to a plug for now.
I was hoping to get the AC going before I started framing up the interior.

Still haven't had a chance to take the cover off and double check everything... May be this weekend before I can get to that.

[opnspaces]

I agree Bob, but here's my reasoning on flipping the breaker on the converter.

The AC worked fine when sitting on the floor. At this point I'm assuming the AC is the only load on the circuit.

Once he puts the AC on the roof, everything else in the trailer can draw off that same 15 amp shore power line.

Although not quite the same, my experience is dry camping with my Honda 2000i generator. With low batteries (a night of heater)the generator will usually run either my microwave or the AC. But only if I shut off the converter. If the converter (or even the refrigerator on auto)is on at the same time, the microwave runs slow or the generator overload breaker blows with the AC.

So by shutting off the 40 amp converter, I remove a load off the generator and the microwave runs normal and the AC doesn't trip the overload breaker.

So while it's not the same situation, his the converter is putting a load on the system that wasn't there when the AC was just sitting on the ground Plus the test is free and you don't even have to get on the roof to run it. It only takes a minute to throw all the breakers and remove all the load off the shore power. Then either the AC runs or it doesn't

[Bob_Landry]

The AC should run on a 15A circuit as long as that's all that's on at the time and had adequate voltage. As far as the converter overloading anything, probably not. The breaker that powers the converter is separate from the 20A one that feeds that AC. If the converter had a problem creating an overload, it would likely trip it's own breaker. If there was low voltage, the AC would start and run, unless line voltage was VERY low, but would eventually draw excess current and probably trip it's own breaker.

[opnspaces]

Is the unit still on the floor or is it mounted on the trailer? If it's on the trailer, and if the trailer has a converter charger, it might be overloading the circuit. Try flipping off every breaker in the trailer except the AC breaker and then see if it will run. Or try running a heavy duty extension cable up onto the roof and test it that way. That will eliminate any other phantom loads that might be causing a voltage sag.

[BoxerPitMix]

Busy weekend, didn't really get to mess with it.

If I remember correctly, the breaker to my garage may only be a 15 amp... I did, however run the A/C off of that same circuit when I first got it for a long time just sitting on my tailgate.

I'll have to take a look at the little generator I have... Don't know much about it. I don't hold much faith in that thing, it's just a cheapy I picked up to use around my property to run small stuff.

[peirek]

I have not heard you answer the question on the amp rating of the circuit you are plugged into. As pointed out there are likely other draws in the trailer.

[CavemanCharlie]

I was thinking that after returning to the upright position that the oil would return to the bottom too. Yes, there is always a little oil circulating through the system. I Still think it's not the fault of setting upside down and it is something else maybe like what Bob Landry said.

[Bob_Landry]

The units are supposed to stay upright so the compressor oil does not migrate. Once it's returned to upright and sits for an hour or so, the oil will return to the compressor. A certain amount of oil migrates throughout the unit during operation anyway, so that's not a concern. Since the AC was operating before, it's unlikely that turning it upside down caused any type of mechanical damage. The compressor is starting and trying to run, but what you are describing sounds like it's lost it's run capacitor. It's also very unlikely that being turned over would have damaged the cap in any way, so I would look for a wire that had come off of a terminal somewhere. And no, it doesn't need a hard start kit.

[BoxerPitMix]

I don't have any intention on air conditioning my horses. LOL

This is for the LQ. And I've put window units in older horse trailers plenty of times, but I don't really want to put that ugly thing on the front of a brand new horse trailer.

[RoyB]

Sometimes its a good money deal - sometimes you have chalk it up to a bad experience...

You could have got a brand new WESTPOINT 8000 BTU window unit with remote control on sale for the past month from ACE HARDWARE for around $175... This one draws around 650WATTS I think... Should run great from a 2KW Honda type generator...

My horses always got the 255 type air conditioners... Two windows down at 55mph...

Just my thoughts
Roy Ken

[BoxerPitMix]

Here's a picture. Pretty sure this is a rotary compressor, isn't it?
I have a lot of experience with AC in cars & trucks, but not with anything like this other than new installs.


This evening I'm going to double check all my wiring again. I've installed dozens of these units, but who's to say I didn't pinch a wire or something this time.
I'm gonna take the beast on a little ride tomorrow about 15-20 miles away. The place where I'm taking him has a fairly bumpy dirt road where I unload him... I'll tie him off oustide and drag it down that road and back, see what happens.

[Bob_Landry]

They are rotaries but I'm not going to argue with you. I guess I've been confused for the last 15 years.
Have you even had to cover off of a roof top unit?

[Altern]

I doubt its a rotary compressor. Hermetics were used almost exclusively in these small units and it would have a piston.

[Bob_Landry]

allen8106 wrote:
Likely by turning it upside down oil has drained into the compressor cylinder. When the piston tries to compress the oil it can't but keeps trying. As the locked rotor amps of the compressor climbs above the trip point it trips the breaker. Your compressor is now oil slugged. Could be that it drains down over time, could be in the cylinder permanently.

What??? These are rotary compressors. They don't have cylinders, pistons, and connecting rods like air compressors do.