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lamato · 08-22-2017, 08:31 AM

We're in Alabama and just found out what we thought was a generator problem, turns out to be an air conditioning problem. The people at the generator place told us that we should not even run our air condition as it is drawing too many amps. Did I mention where in Alabama!

We have a 2012 extended and we're looking for a place to get this air conditioning fixed. Any help or advice anyone can offer would be greatly appreciated. Obviously, we are out of warranty.

Thank you,

Laura and Vince

HowieE · 08-22-2017, 08:39 AM

If you find a shop that will honor the extended warranty don't mention you were using a generator. You need a mim. of 3000 watts to safely use the AC and that assumes you are not using power with other equipment.

Operating under low voltage, excessive current draw, will cook the unit and I doubt it will be covered.

The older ACs had a low voltage indicator that gave warning of low voltage.

uncle_bob · 08-22-2017, 08:39 AM

Hi

Ok, let's back up a bit.

How big is the generator? If it's a 2KW then no matter how well the stock AC is running, it will not power it. If it's a 3KW unit then you at least have a chance.

Does the AC run OK on shore power? If so there isn't a lot you can do to "fix" it. Checking the capacitors is about all there is. That's not a really tough process.

Has the AC been modified in any way? If you have a "soft start" kit of some sort on it, that gizmo may be broken. Getting one repaired is usually a "back to the manufacturer" sort of thing.

If the AC pops breakers on shore power and it's not the capacitors, you do indeed have a problem. The answer likely isn't a repair as much as a replacement. There isn't a lot in an RV AC unit. You have a thermostat, a couple fans, and a compressor. If it's a fan or thermostat you can take care of it. The compressor is usually what goes if it's tripping a breaker.

Lots of Fun !!!

Bob

Pahaska · 08-22-2017, 08:43 AM

Does the AC work on shore power?

The most usual problems with RV AC units is a failed or degraded start capacitor, resulting in a high current draw when the AC starts. This may result in more than current the generator can support, but still start on shore power.

lamato · 08-22-2017, 08:59 AM

The a/c runs great on shore power. It only surges when we use the generator. The generator experts say nothing is wrong with the generator. That cost us $105!

TG Twinkie · 08-22-2017, 09:07 AM

What is the rating of the generator under constant load?
Do you have the generator in eco mode?
What size is the A/C?

uncle_bob · 08-22-2017, 09:31 AM

Quote:

Originally Posted by lamato

The a/c runs great on shore power. It only surges when we use the generator. The generator experts say nothing is wrong with the generator. That cost us $105!

Hi

What's the make and model of the generator? We're guessing about it's capabilities. The issue may simply be that the generator is not big enough.

Bob

lamato · 08-22-2017, 09:51 AM

The generator and AC came originally in the Airstream Interstate.

lamato · 08-22-2017, 09:51 AM

The generator is a 2.5 KW

uncle_bob · 08-22-2017, 10:10 AM

Hi

That generator is right on the edge of what will run your AC. This assumes you still have the stock 13,500 BTU AC. If you have much else running (converter, fridge, water heater) things will trip out. It's probably worth getting the capacitors checked. Most RV service places should be able to do that. Some people even travel around with meters that will check them ....

Bob

Titus · 08-22-2017, 11:07 AM

Agree that the generator is marginal for running the A/C, but it has always worked for us. Current draw upon starting is 18A, but then drops a few amps once started. We have had it pop the breaker when running on a 20A GFCI at our house, but no problems otherwise. I have never tried running anything else when running the A/C off the generator. The EMS is supposed to shed loads in some priority order, but I have not tested it to see if it actually does. I knew it could handle more, so didn't try.

ben322 · 08-22-2017, 01:58 PM

Check the oil level in the generator. If it's even slightly low, the generator may surge or even stall. That said, check that everything else is off.

Wayne&Sam · 08-22-2017, 02:08 PM

Quote:

Originally Posted by lamato

The a/c runs great on shore power. It only surges when we use the generator.

Then it's probably not an a/c problem, unless something is going on it so it draws just slightly too many amps.

Consider putting an EasyStart on it. Your 2.5k generator will run it then.

lamato · 08-22-2017, 07:40 PM

Quote:

Originally Posted by Wayne&Sam

Then it's probably not an a/c problem, unless something is going on it so it draws just slightly too many amps.

Consider putting an EasyStart on it. Your 2.5k generator will run it then.

What's an EasyStart and can it be used in a 2013 Airstream I Interstate?

HowieE · 08-22-2017, 08:05 PM

While the generator and AC are running measure the voltage. If it is below 105 you will cook that compressor and it will be $1000 to replace it.

If the AC will start the capacitor has done it's job. It is only used during the start up.

lamato · 08-22-2017, 08:10 PM

The AC starts using the generator. Sometimes it stays on and sometimes it doesn't. I don't want to cook the generator or the AC.

Boxster1971 · 08-23-2017, 08:17 AM

The line voltage makes a lot of difference. Two nights ago we were in a place that had low voltage. Even my Progressive EMS would shut off the power when voltage dropped below 104V. When power was on it would start the A/C, but then because it was drawing so much current at the lower voltage the Precision Circuits Inc. (PCI) power management system would shed all other power like TV and microwave. Last night was in better campground with 118+V and then everything worked normally. Low voltage is a real problem. I need also need to check voltage on my generator as I have had some similar problems when trying to run A/C off generator.

HowieE · 08-23-2017, 10:15 AM

You can buy a very inexpensive plug in volt meter, around $10.00, and know what you are working with every time you plug in at a campground or while the generator is running.

Mine is plugged in next the the transfer switch for the microwave and the AC. Anything below 105 and it is time to shut off the AC.

Keep in mind. You may be fine if you are the first to the campground but as others come in the voltage may drop so when it is hot outside keep an eye on things.

FlyFishinRVr · 08-23-2017, 01:39 PM

Quote:

Originally Posted by Boxster1971

I also need to check voltage on my generator as I have had some similar problems when trying to run A/C off generator.

Maybe this is a dumb question, but since I've seen comments like "don't run your A/C off your genset" in this thread, I'll ask it anyway: Are we supposed to (as in "by system design") be able to run our rooftop A/C via the genset, or is this just something that people do but it's not recommended? On every RV I've ever been in, I've run the A/C off the genset. I never plug in...when I go "glamping", I go as far from other people as my "glamper" will take me.

When I look at the specs for my van, I have a 2500W genset and a 1700W A/C (max cooling mode, as in compressor on). I realize the startup current for the A/C unit can be quite high, potentially spiking over the 20A breaker for it, especially if the voltage is low, but other than that, shouldn't this all just work?

Also, there is nothing in the manual about NOT doing this, so it leaves the issue a bit open to interpretation.....

ben322 · 08-23-2017, 05:33 PM

We run ours all the time via the genset. Two years ago, we were coming back from OBX with 7 people and temps close to 100, we ran the rear AC from the genset for well over 6-hours because of traffic.