We're going to a CG that has different rates per site by how many amps they provide. There are 20, 30, & 50 amp rates. We will only be spending the night and will definitely need to run the A/C. Will 20 amps suffice?We will be using our Roadtrek 170 - B camper.

it should but don,t turn anything else on.

Probably yes, and with no problem, as long as you are not running anything else, like electric on your water heater, microwave, hair dryer, televisions, toaster oven, electric frying pan ... all at the same time.Simple test? Plug your camper into your home wall outlet. Homes are usually 15 or 20 amp circuit breakers. Make sure nothing else in the house is turned on with that circuit. Now power up your RV. Flip on the air conditioner. It will run, no problem, as the amp draw is far less than 15 or 20 amps. Now flip on your water heater. Now flip on that hair dryer. When you reach the 15 amps, the breaker in the house will trip. There you have it. You know where the limitations are. But yes, the air conditioner by itself will run with no problem on 15 - 20 amp circuits, but everything else might not. Try it... see what happens at home. Then you'll know.

If it is a 13,500 BTU air conditioner it will take about 23 amps to start it, once running it will take about 15 amps. It's likely your converter and a few other loads will be running at the same time. I could run my 13.5K AC on my old unit at home on a 20 amp breaker, but it was a stretch on startup. But I only did that with no other loads and for short periods of time. And if you plan on running the microwave at the same time it definitely won't work. In my opinion, for long term use (more than a couple of hours), 20 amps just isn't enough. If it's a 15K Air conditioner, you'll definitely need the 30 amps.

20 amps will run the a/c just fine, along with some low amp drawing appliances. Worst thing that can happen is the breaker will trip. Then you know to turn something off.

What is the COST difference between 20 and 30 amps. Usually, 20 amps is for RV's that do NOT have a AC system, hence they do not need the 30 amp pole. Your RV is designed for 30 amp, due to the AC system. Doug

Will A/C run on 20 amps? | Good Sam Community

20 Replies

RJsfishin
Explorer
Jan 28, 2017
We lived in our MH for 5 months thru a very hot summer, on a borrowed 20 amp breaker. Dumped the breaker 1 time in 5 months when we accidently hit the Micro while the A/C was on.
AllegroD
Nomad
Jan 28, 2017
How do you monitor your available volts. I would get a Kill-A-Watt. Many CG have circuits that are "ganged" and you may have brown out situations. In other words the circuits are under powered. An AC will suffer heat damage if the voltage drops below 105. You may not know that you are even in a brown out and incurring heat damage, but this is reducing your AC life span.

I would also suggest a Progressive Industries EMS as they will turn off (stop or interrupt) the power when it reaches 104 voltage and back on when 105 or above. This may sound like a bad idea but would you rather be uncomfortable for a few hours or loose an expensive AC years early.
Jayco-noslide
Explorer
Jan 27, 2017
We once had a small trailer and the campground only had 20 amp. Very hot so we did run the AC but I didn't like the way it sounded so I don't think I would again.
turbojimmy
Explorer
Jan 27, 2017
Yes. As others have said you will have little head room but it will work. Mine's plugged into a 15A circuit at home and I can run the AC so long as NOTHING, and I mean NOTHING else is plugged in.
dougrainer
Nomad
Jan 26, 2017
pasusan wrote:
OP here...

Thanks for the replies! So, it looks like it will work OK as long as the breaker doesn't trip and the only thing that would be bad for the A/C itself is low voltage.

I did do a search of archived threads and there was one that said my Roadtrek A/C is essentially a window A/C and that would normally run on a 15 or 20 amp circuit... So - I think it's all good.

As far as price difference - it is a whole 7 dollars between the 20 amp and the 30 amp rates. ;)

Breakers are not installed to trip from overloading or low voltage. When you have a CG pedestal that does NOT supply the amps for your unit, the voltage can drop and that will harm components in the RV not just the AC system. SPEND THE 7 DOLLARS. Your window unit has about the same amp draw as a RV roof top unit. Remember, you are LIVING in your RV and there are other items running on 120 while you are in it. The Power Converter. The refer. The TV's and other kitchen type appliances. Microwave if you have one if you use it. This may be the most expensive 7 dollars you have ever saved:B Doug
Shadow_Catcher
Explorer
Jan 26, 2017
One of the assumptions is that the 20A breaker will trip before overloading catastrophically, I for one am not that trusting of the breaker or pedestal.
time2roll
Nomad
Jan 26, 2017
I would get 30 amp site if you want air. Yes the air runs on a 20 amp circuit. Just check the branch circuit breaker rating in the RV power box.

Otherwise to run on 20 amps you may need to turn all breakers off except the main and the A/C. The rest will need to run on battery and propane. Voltage will still be a concern on this minimal circuit depending on the connection and shared usage.

For a quick overnight it might just be fine. Just so you understand the limitations.
sch911
Explorer
Jan 26, 2017
Ask yourself is it worth the $7 to insure you have adequate power and no risk of overload? The answer is easy, of course it is....
wa8yxm
Explorer III
Jan 26, 2017
Will 20 amps run ONE air conditioner: YES (however read on)

IN fact if you check your breaker box you will likely find a 20 amp breaker there marked AC or A/C (Air Conditioner) so ti's a 20 amp device.

Mind draw 13-14 amps running.

However your Converter is also drawing power 1-10 amps depending on the size of the converter and condition of your batteries and thigns

The fridge draws 3-4 when cooling on A/C (force it to Gas if you can).

And make sure the water heater is either A: off or B: gas.

YOu can more or less ignore the contribution of modern flat screen TV's but older CRT's are close to the Fridge in power draw. 1-4 amps.
Charlie_D_
Explorer
Jan 26, 2017
Spend the $7.00. Lot's of "yes" on this thread BUT does the 20 amp outlet provide full voltage and 20 amp? 20 amp receptacles are not necessarily wired correctly and have undersized wiring. Many campgrounds have low voltage, poor outlets and bad wiring. Lot's of posts on this forum about wiring connections being damaged, overheated connections, etc. Kinda like home wiring with 15 amp receptacles and then someone changes that to 20 amp thinking all will be well. Your choice.