Most RVs use less than 20 amps for normal operation. ACs are a high-amp appliance, and RV AC amp draw is about 13 amps for commonly used air conditioners from Dometic and Coleman.
RV AC Amp Draw – Making Sure you Have Enough Power
There are an estimated 9 million RV’s in the U.S., and about 1 million people are “full-timers”, meaning that they live in them all year. Because RV’s aren’t really designed for cold weather, they will spend most of the time where it’s warm – and that means air conditioning will be a high priority. With well over 16,000 RV campgrounds and parks in the country, the question of adequate electrical power can be a real concern. This article will address several issues related to this topic.
Electrical Requirements for an RV Air Conditioner
RV air conditioners run on 120VAC (standard alternating current used in homes). Most RV’s of several types have one air conditioner, while some of the much larger ones have two. They are rated by their cooling capacity, which is measured in BTU’s. The standard size is 13,500 BTU, but some are 15,000 BTU.
Two very popular models are the Dometic 13500 btu rv ac, which draws 12.4 – 13.3 amps, and the Coleman 13500 btu rv ac, which is rated at 13.3 amps. The electrical power provided by all but the poorest campground will be sufficient to run at least one RV air conditioner of this type.
Note: The 15000 BTU RV air conditioner amp draw is a little higher – 13 to 15 amps – so, if that’s what you have, you’ll need more power at the campsite or from your RV generator.
Amperage Requirements for an RV Air Conditioner
How many amps does a RV AC use?
The average amperage requirement for an RV air conditioner is between 11 and 16 amps while it is running. This will vary, depending on the size of the AC, the model, and its age. Newer models are usually more efficient than older models, requiring closer to 11 amps than 16.
When an air conditioner first starts up, however, there is an additional RV AC amp draw of about two times the running amperage that lasts for a fraction of a second. Since RV campgrounds have either 30 amp or 50 amp connections, they are designed to handle this brief, initial surge on start-up. The exception to this is if there are too many other electrical appliances running inside the RV at the same time the AC tries to start.
Can you run RV AC on 30 amp outlets? Most likely you can, but only if there aren’t a lot of other appliances drawing amps.
Here is an example:
Let’s say it’s breakfast time, and a camping family has their RV plugged into a standard 120V, 30 amp electrical circuit. The refrigerator is running, using 6 amps. The coffee maker is running, using 6 amps. Someone is making toast, using 8 amps. Someone else puts a breakfast sandwich in the microwave, using 8 amps. This is a total of 28 amps. If the air conditioner should switch on now, the 30 amp circuit breaker at the pedestal where the RV is plugged in would most likely trip, since this family is already using almost all 30 amps of power.
In our example, the RV was plugged into a circuit that would handle the amperage requirements of the air conditioner, but too many other appliances were already using most of the available power for it to start.
Another scenario that can happen is that someone could turn on an appliance while the air conditioner is already running that could overload the circuit. In both cases, the circuit breaker would trip, cutting off all power to the RV.
Pushing the Limits – Using a Smaller Amp Circuit
There are times when you might not have a 30 or 50 amp circuit available, but the use of your RV air conditioner is desired. For example, you might decide to visit a relative or friend at their home while traveling to another state to a campground. Very few residences have a 30 amp circuit that you can plug into, but they probably have a 15 or maybe even a 20 amp circuit that you can reach with your RV electrical cord.
In this case, you will need an adapter for the end of your cord, since the standard 30 amp plug is very different from a typical household receptacle. Assuming that you have one, you can use it to connect to their standard 120V house electrical supply.
Will the RV air conditioner work? Can you run a RV air conditioner on 15 amp circuits? What about running my RV air conditioner on 20 amp power?
These are common questions related to the bigger question – How many amps does an RV AC Use?
When we remember that the average RV unit will draw between 11 and 16 amps when running, it will probably work on a 20 amp circuit, and maybe on a 15 amp circuit. The key will be to have no other 120V appliances running inside the RV, and hope that the initial surge on start-up does not trip the circuit breaker.
In any case, you might be pushing the limits of your host’s electrical circuits and putting a possible overload on them. If their circuit breakers are in good working order, they should trip to prevent a serious problem, but it might be best to use fans to cool your RV for one night and not take any risks.
Using a Generator for Powering an RV Air Conditioner (or Two?)
Some folks who own RV’s like to get away from the crowds and go camping where there is no electricity – boondocking, dry camping or off-the-grid camping are names for it.
While they could get by for a brief time using just the batteries in their RV, they would probably be best served by using a portable generator for power – especially since their batteries won’t run the air conditioner. If their RV happens to have an onboard generator, it should be able to handle whatever air conditioner the RV came equipped with.
The power output of a generator is rated by watts, so to know what size generator you will need for an RV air conditioner, you will need to know how many watts it requires. A typical 13,500 BTU unit draws about 3,600 watts on start-up and about 1,300 watts after that.
Shopping tip: While it seems like a generator of at least 4,000 watts would be needed for this task, many people in the RV community have found that a quality generator of 3,000 watts will usually handle a 13,500 BTU RV air conditioner.
As an additional help, there are “hard start” kits like this one that store a charge and then give the air conditioner compressor a “kick start” to enable a portable generator to start the unit easier. If you want to get one specifically made for RV air conditioners, this is one that you might prefer.
If you have a larger RV with two air conditioners, they will each be wired to opposite sides of the 50 amp (split) system to prevent overloading when they are both running. Though some of the newer portable generators have a 30 amp RV receptacle, with an adapter on your supply cord it will supply power to only one side of the 50 amp system. This means only one of the air conditioners will have power available to it. So, with the appropriate size generator, you could probably run one of the air conditioners, but not both.
Adding a 2nd Air Conditioner to a 30 Amp RV?
Adding a second AC to a 30 amp RV will take more careful consideration.
Just as we have seen above, many RV’s come equipped with an air conditioner and operate with a 30 amp connection. A second air conditioner could be added, but only one at a time could be run without tripping the circuit breaker. Adding a 2nd air conditioner would also require either having it done professionally, or by someone who is knowledgeable about how to run new electrical wiring from the RV main circuit breaker panel to the new air conditioner.
A few very creative individuals have been known to install a small 5,000 BTU window air conditioner in the bedroom of their RV (after it was parked). This was plugged into a standard wall receptacle and only used at night to keep the bedroom cool for sleeping. The main air conditioner was turned off to make sure it didn’t come on, since both running at the same time would overload the circuit breaker.
Plan Ahead to Stay Cool
In recent years, the RV manufacturers have been designing their units with more and more comfort in mind. One of these comfort items is the air conditioner. Most RV parks and campgrounds have been busy upgrading their electrical systems to handle the increasing amperage requirements of the rigs that fill their parking spaces.
As long as you do a little research before choosing a campground – making sure they have the right amperage hookups for your rig – you can be fairly confident that you will encounter no difficulties when it comes to running your RV air conditioner.
