Running RV air conditioner on 15A or 20A outlet

[S.Rodimus]

Our motorhome is 30A. We have a dogbone adapter to allow us to plug into a regular (15A) home outlet. And I know that if we do that, we won't be able to fully use all of the electrical components in our RV, especially not many of them all at the same time, and particularly maybe not the air conditioner.

We don't have a 30A service to plug into (and have no plans to install one), and are coming up on an instance where we may have a guest sleeping in the RV for a couple of nights during potentially hot weather.

So my question is:

If we use the dogbone adapter to plug our 30A motorhome into a 15A outlet, and run only the air conditioner overnight -- should we expect to encounter any problems?
What if we find a 20A outlet to use instead? (some of ours might be - TBD)

 

[creativepart]

Thing is, it’s tough to ONLY run the A/C. The converter will still be running some 12v loads. And you can’t turn that off because the Thermostat needs its 12v power to operate the A/C. If you can disable the charger in the converter with a breaker that would certainly help. But your guest can’t use the microwave or any outlets. Fridge and water heater would have to be on LP, of course.

Before we installed a 30 amp outlet at our old house I plugged into a 15-amp outlet and ran the A/C for a day and overnight. The next morning that plug was burned to a charred crisp. Luckily the circuit breaker tripped and there was no other damage. I will add that I had plugged in with a 50’ extension cord and I’m sure that played a role in the problem.

A 20 amp plug would help as you mentioned. Use a heavy duty cord, with a short length.

 

[Lv2Roam2]

My simple answer is 'don't do it.' Plenty of good info shared by Creative Part. Generally - a 15-amp circuit will help you keep a battery charger going, sometimes a charger and a residential frig. You do not want to risk a fire.

 

[IOS 3]

Your guest is trusting you when they sleep in this rig. Don't do this. Fire hazard on both ends of the equation. Adding a 30-amp circuit is easier than it sounds. Call an electrician.

 

[Wmlunt-WO]

I added a soft start to my a/c and was able to run off 15a for a few days in Arizona while mooch camping at a friend’s driveway.
Bill

 

[klook]

I would turn everything off in the breaker panel and run on the battery for lights and other power. Maybe jump in a second battery. Then I would only use a very short and heavy extension cord if necessary. Run a second cord from a separate outlet and put a battery charger on the battery(ies) if you can.

 

[cboydfl]

I have an Intent 29L. It has two smaller AC's in a 30 amp service. I can easily run one AC on a 15 am circuit, especially after adding soft starts. My two cents.

 

[kamphiker2]

not knowing your exact MH as various models have different AC units and Amp draw varies. 15 amp service and guessing various extension cords etc. from your House 120V 15 amp service etc. running the Roof AC runig more than a few minutes at at time will will overheat the various plugs & cause a Melt Down. My 2020 MH with 2 AC unite has a power control & when on 15 amps shuts down various power usage. at minimum on a not so hot day the amperage on just 1 AC unit by it self is 15 - 17 amps. My Best guess you will have issues trying to cool your RV off of 15 amps. Keeping Batteries charged & running your Refrigerator 15 amps would be sufficient.

 

[dnta11]

Maybe not a popular answer, yet still true for me. As someone said, MH's and A/C's are different so who knows in your case. Yet I had a 2017 WB26A for a few years and now a 2018 22M for a few as well. I've been able, without incident, to plug both of them into 15/20 amp outlets when visiting folks (even multi days) and run my A/C provided, as mentioned, 1. both HWH & Fridge are on Propane 2. I plug chargers into 12v 3. If I'm going to plug in a coffee pot or use the microwave or MOST anything I turn the A/C off (exception has been having my computer plugged in, which has not been an issue.) I'm 100% conscious of what I'm up to the whole time so as not to slip up, and have not had a problem myself. PS Although I have been grateful I spent the bucks to get a 30 amp service at my 'home' (my primary landing spot 1/3 of year - on the road the rest of the time.)

 

[TimothyPaul]

I think it depends on your AC unit. I have a Coleman and added a soft start. I use a power watch dog so I can monitor the current. Typically even with the soft start I’ll pull between 15.5 -16.7 amps running just the AC. So on a 20 amp circuit as long as I watch my devices, I can run the AC, on a 15 amp circuit as- it is too much and will trip the breaker.

 

[klook]

A soft start does not lower the running amperage. It buffers the starting amps so you don't see a big spike. Mine starts the blower motor first and then kicks in the compressor.

 

[bigbAZ]

What if we find a 20A outlet to use instead? (some of ours might be - TBD)

Almost all homes, built to code since the very early days, will have at least two-20 amp circuits serving the kitchen/dining plugs and a 20 amp dedicated circuit to the laundry, so if you can use one of those (with no other loads) it could work.

If the home is fairly new and built under more recent codes, at least one 20 amp garage outlet per stall would be required. All homes built to the 1994 code or later will also be required to have the bathroom plugs on a 20 amp circuit, although this circuit can share with multiple baths and powder rooms.

There are a lot of variables though, we don't know the rating of your AC nor do we know the weather. I've seen my 13,500 btu Coleman Mach hit close to 18 amps at times.

 

[wahoonc]

Another thing that is quite often overlooked is that electrical circuits are designed to be run at 80% of maximum rated load continuously. If you are going to exceed the load for more than 3 consecutive hours you are exceeding the design of that circuit and may cause issues.

I know that my rear AC on Itasca pulls about 14.5 amps running at full load on a hot day. The front is a bit more. Soft starts do help with to soften the start up to keep from popping a breaker. It is the constant load that can cause problems.

Aaron

 

[S.Rodimus]

Just as a follow-up on this, wanted to let y'all know that we're looking into getting a 30A/50A outlet installed on the outside of our house next to where the RV parks.

 

[S.Rodimus]

UPDATE: We are still looking into getting a 30A and/or 50A service installed on the outside of our home, for this purpose. We will not be attempting to run the RV A/C on an extension cord of any kind.
However, last question .... there shouldn't be any problem running just the RV TV and 1 RV ceiling light on an extension cord plugged into a normal 15A outlet that is already on the outside of the home, right? (I.e. until we can get the 30A and/or 50A service installed on the outside of our home.)

 

[Morich]

TV and a few other things should not be a problem. One practical way to look at that is checking our house where we plug the TV and spot how many have several things like TV equipment and other things in the same outlet! Often not a problem!
It's the hair drier, microwave, and air that are real problems!

 

[S.Rodimus]

...One practical way to look at that is checking our house where we plug the TV and spot how many have several things like TV equipment and other things in the same outlet! Often not a problem!...

That, plus my basic electrical knowledge, is exactly my logic.

 

[Waterbug]

UPDATE: We are still looking into getting a 30A and/or 50A service installed on the outside of our home, for this purpose. We will not be attempting to run the RV A/C on an extension cord of any kind.
However, last question .... there shouldn't be any problem running just the RV TV and 1 RV ceiling light on an extension cord plugged into a normal 15A outlet that is already on the outside of the home, right? (I.e. until we can get the 30A and/or 50A service installed on the outside of our home.)

There should be no problem running the RV TV on a 15 amp outlet, however there are probably other outlets in your home on the same circuit. Outside plugs are usually GFCI circuits and sometimes connected to a GFCI in a bathroom or garage. If someone uses a hair dryer or power tool on that circuit it could potentially trip the breaker. Also, RV lights are typically 12 DC, and run off of the RV house batteries.

 

[S.Rodimus]

There should be no problem running the RV TV on a 15 amp outlet, however there are probably other outlets in your home on the same circuit. Outside plugs are usually GFCI circuits and sometimes connected to a GFCI in a bathroom or garage. If someone uses a hair dryer or power tool on that circuit it could potentially trip the breaker. Also, RV lights are typically 12 DC, and run off of the RV house batteries.

We have all of our home outlets and circuit breakers mapped out to a T. The only other thing on this circuit is our dishwasher, which for super-safety won't be used during the time the RV is plugged in.
And per my other post -- our RV house batteries are currently dying, so they can't be relied on at all. (We will be replacing them in the next couple of weeks; just not before this overnight plug-in needs to happen).

 

[Morich]

I think you have the correct plan in mind but I might pointout some ideas to consider. It is not that anyone item will overload the braker or any part of the deal, but more often it is the total of a number of things combined that will over load it. You might want to consider testing the air running but do it when you have turned off most of the other loads. Just like not using the dishwasher at the same time?
The air is the big est load but it has a better chance of not tripping the breaker if the air and converter are not running at the same time!
One way to try things, as long as you know where to fix the tripped breaker, is to turn off the battery disconnect switch and reduce all the loads you can when wanting/needing some cooling. The batteries do not directly add to the load on the AC power but when we use batteries, the converter tends to come on to replace that DC power we use! Same result but a round about way to get there?
If we think of rotating different loads on at different times, we can get the use of several things, just at different times. For instance, I might consider turning all the loads off that I can find but trying the air for a few hours to cool things before I want to go to bed!
Maybe it trips the house breaker but that is not a super biggie if we know where to flip it on and only use what works at any given time.
Or maybe run the generator for a bit if not a problem where you live? Maybe a bit of roughing it but certainly several steps above a tent in a field!