Can I run 15,000 BTU air cond with RV plugged into my house?

[rob_engineer]

I have 39ft Gulfstream Friendship 102 diesel class A. My 15K roof air works when under generator power, but overheats and trips breaker when the RV is plugged into my house. I have a normal 20 amp outlet on my house. I use a 50ft, 10 gage cord from the house to the 50 amp cord on the motorhome. If I shorten the 10 gage cord, is there a chance that my household power will be enough to power the air conditioner? In my current setup, the voltage to the air conditioner drops from 119 (no load) to 101 (full load). While on generator power, it only drops to 113 volts full load. I like to hang out in the RV in my driveway. What do I need to successfully run the 15K roof air, other than use my generator? I am also considering putting a portable air conditioner in the RV for driveway use instead of using the roof air. Your thoughts?

[rob_engineer]

joebedford wrote:
Just curious - what do you mean by a "normal" 20A house circuit? Maybe that's what you have, but where I live, a "normal" house circuit is 15A.

I have two 30A RV receptacles for when friends come to visit. Mine stays plugged into a 15A circuit.

What I mean is that it is a typical outlet on the outside of my house. Been there since I bought the house 20 years ago. I installed a 20 amp receptacle at that outlet location.

[rob_engineer]

SkiSmuggs wrote:
After reading this thread, I think the OP should have run a 50 amp extention cord to the 20a house circuit, then used the dogbone adapter for the final connection. Using a 15a extention cord over that distance is asking for problems.
And if the OP reads this, I am curious as to the resolution of the problem.

I am not using a 15a extension cord. I am using a 10 gage cord, which is what 30a RV cords are made from. I still have not found the exact problem, but it is most likely that the compressor motor is simply bad and gets too hot. It overheats even when fed with 113 volts measured under running load.

[joebedford]

Just curious - what do you mean by a "normal" 20A house circuit? Maybe that's what you have, but where I live, a "normal" house circuit is 15A.

I have two 30A RV receptacles for when friends come to visit. Mine stays plugged into a 15A circuit.

[pianotuna]

Running the air with low voltage causes cumulative permanent damage. Below 107 volts shed loads. If that is ineffective turn off the air. Put an autoformer on your wish list.

[SkiSmuggs]

After reading this thread, I think the OP should have run a 50 amp extention cord to the 20a house circuit, then used the dogbone adapter for the final connection. Using a 15a extention cord over that distance is asking for problems.
And if the OP reads this, I am curious as to the resolution of the problem.

[otrfun]

rob_engineer wrote:
. . . I'm coming to the conclusion that my old unit is toast.

Sorry to hear your a/c may have bit the bullet 😞

FWIW, if/when you start looking at new a/c's, recommend a close look at the Coleman Power Saver units. Chances are you can reduce your LRA and continuous current draw 25-35% vs. your current unit. Not so much a big deal when operating on commercial power, but definitely a big deal when operating on generator.

Also, there's a significant difference in performance between the NOS (new old stock) xxxxx-8xx series Coleman Power Savers and the latest xxxxxx-9xx series Coleman Power Savers. For anyone considering a Coleman Power Saver make sure you get the latest "-9xx" series.

[rob_engineer]

greenrvgreen wrote:
I'd start by replacing the breaker. It's cheaper and (IMO) more likely to be the problem.

If the AC won't run properly on a fresh breaker then it never did, not even for the PO. But before I bought a new AC I'd take a hard look at the wiring.

There are four bolts that hold a roof AC to the vent orifice. If you remover those you can press the AC up and on to the roof. Somewhere at the side of the vent orifice you'll find the AC hardwired in with thumbscrews. Before I went out and bought a new AC I'd try powering it directly via the hardwire connection, just to see.

Also, have a look around. Is the water heater on electric? The battery charger running? These things are FAR more likely to be the problem. Maybe your batts are dead and the converter can't stop trying to charge them.

All good thoughts. I already replaced the breaker. Even temporarily put in a 30 amp one. Still kicked after running for 5-10 minutes. I also cleaned the fins. They are not in great shape since the unit is 19 years old. I haven't tried direct power, but I likely will before buying a new unit. However, I know the generator supplied over 113 volt to the terminals even under load, so I think a wiring problem is unlikely. I'm coming to the conclusion that my old unit is toast.

[greenrvgreen]

I think H wins it--it could be just as simple as spraying down the fins.

Also, I want to give a personal thanks to any and all who shut off their AC's at 107V or lower. It is a commendable practice, and very helpful in a crowded campground.

The more people who shut off their AC's the better the voltage is for people like me who are happy to chop a month or two off the 10-year lifespan of their AC for the sake of using it when it's needed most!

[pianotuna]

I shut down the air conditioner any time voltage is lower than 107.

[Hurricaner]

Clean the condenser and your problem will probably go away!!!

Sam

[greenrvgreen]

I'd start by replacing the breaker. It's cheaper and (IMO) more likely to be the problem.

If the AC won't run properly on a fresh breaker then it never did, not even for the PO. But before I bought a new AC I'd take a hard look at the wiring.

There are four bolts that hold a roof AC to the vent orifice. If you remover those you can press the AC up and on to the roof. Somewhere at the side of the vent orifice you'll find the AC hardwired in with thumbscrews. Before I went out and bought a new AC I'd try powering it directly via the hardwire connection, just to see.

Also, have a look around. Is the water heater on electric? The battery charger running? These things are FAR more likely to be the problem. Maybe your batts are dead and the converter can't stop trying to charge them.

[rob_engineer]

I may have a bigger problem. This rig is new to me and was neglected by previous owners. Today I cannot get it to keep running without tripping the breaker even on generator power. It is about 100 degrees here today. The unit cools for maybe 10-20 minutes, then the compressor gets too hot and the breaker trips. I think I need a new air conditioner.

[Oldme]

I have run ours several times like that.
Both at home and while at my daughters on the river.

[2oldman]

greenrvgreen wrote:
I've run a 13.5k AC for hours and hours on 100v or slightly less.

That seems dangerously low.