Understanding RV Electrical Hook-Ups

While I have done a lot of camping over the years, I have never camped in an RV. There are some benefits to camping in an RV (like your own bathroom), however I admit I have always been a bit nervous about how the hook-ups work. When booking campsites, I see they are available, but without an RV I had never given it a ton of thought. My husband, on the other hand, has a lot of experience with RV’s and is often throwing out the idea of renting or purchasing one for our longer adventures. And I admit, I dream of one day being a campground host, where we would potentially live out of an RV for months. These things have led me to learn what I can regarding electrical hook-ups when camping.

Understanding RV Electrical Systems

I asked my husband to explain RV electrical systems and he had me doing math problems. I felt overwhelmed and became concerned I would never be able to figure out how electrical systems worked. I admit though, that I was determined. So I dove in and started researching. Fortunately, others are better about explaining how electrical systems and electrical hook-ups work.

RV electrical systems can be divided into three different categories: the 12-volt DC automotive system, the 12-volt DC coach system (both run by RV batteries) and 110/120 volt systems (run by plugging your RV in or using your generator). When considering hook-ups, the main systems to look at are the 12-volt DC and 120-volt AC coach systems, as the automotive system functions like a car.

In modern RV’s 12-volt batteries are relied on for everything. Once some things like the roof air conditioner, microwave and the refrigerator are turned on they will run on 110/120 volt, but the 12-volt battery is what powers the computer that starts these things up. The 12-volt will allow just about everything else in the camper to work, to include the water heater and the furnace. Key to keeping your 12-volt system working is that you have to keep your batteries charged. You can keep you batteries charged using hookups, your engine, generator or solar power.

Your RV will have either 30 Amp or 50 Amp capabilities. To determine which you have you can look at your power cord. If you have a large plug with three prongs, than you have 30 Amps. Larger, newer RV’s may have 50 Amps; the plug is large and will have four prongs. The number of Amps that you have is the greatest amount your RV can accommodate. Once you know the capabilities of your RV, check out the outlet that you plan to plug into.  Most campgrounds have 30 Amp service though you may find you have 15-20 Amp service, 30 Amp, 50 Amp or a combination of all three. You can tell the amount of power available by checking out the outlets. Should the outlet look like a standard household outlet, small and with three prongs, it will provide 15-20 Amps. A larger outlet with three prongs will provide 30 Amps. The largest outlet with four prongs provides 50 Amps.

Adaptors are available so that you may plug in to different Amp amounts. It is important however, that if your RV has 50 Amp capabilities and the campsite has the option of plugging into 30 or 50 Amps, that you choose the 50 Amp. This will help protect your appliances over the long haul. Should the campsite only have the option to plug into 30 Amps, it is okay to plug in, however it is recommended that one be conscious of their electrical usage in order to lessen the demand being placed on the circuit. The majority of campgrounds use electrical systems with a tolerance range of 20 percent in either direction. Breakers that tripped at exactly 30 amps are significantly more expensive than those with the 20 percent range.

To better illustrate this tolerance range:

Watts=Amps x 120 Volts

For a 30 Amp outlet:

Watts=30 Amps x 120 Volts

Therefore, a 30 Amp outlet supplies 3,600 watts. With the 20% range above and below 3,600 watts, the breaker could trip anywhere from 2,880 watts to 4,320 watts.

Rarely will tripping the breaker be an issue for RV’s with 30 Amps. These typically have appliances that have a power requirement well within the limits of what is available at campgrounds. This is more of a concern with 50 Amp RV’s that are hooked up to 30 Amp outlets. These RV’s have appliances that require more power, like heaters and air conditioners. An RV with 50 Amp capability plugged into a 30 Amp outlet will only be getting about one third of the power it needs to run a full array of appliances. If the RV owner is not careful, the RV’s power needs may burn up a 30 Amp plug.

Choosing your Site When Considering Hook ups

Many campgrounds offer sites for different length vehicles. If planning to hook up your RV, make sure when reserving your site that you choose one that will accommodate the length of your vehicle. If you are unsure, rather than making an online reservation, contact someone who can answer your questions, whether it be staff at the campground or forest service employees for the area where you will be. Pull- through sites are ideal for being able to maneuver your RV into place and it is a great idea to choose one of these if it is available.

Plugging In

An RV will have a heavy-duty power cord that is typically 25 feet long. As noted above it will have either 30 Amp or 50 Amp capabilities. Upon plugging in to the electrical source at the campground it will supply power through the RV. Once you are plugged in, part of the 120 volt AC current is converted to 12-volt DC current, which will allow you to use the appliances in the RV that run off 12 volts. These will likely include the furnace, lights, fan over the stove, vent in bathroom, water pump, gas leak detector, stereo and refrigerator when in LP gas mode.

When arriving at the site, before pulling in and hooking up your RV, it is best to get out take a look at the  site, paying attention to any less than ideal places to park (like a hill or a particularly muddy spot). It is important to then consider where your RV hook-ups are and make sure that you position your vehicle so that they can easily connect. It is recommended that you develop a routine when you are preparing to hook up your RV in order to avoid electrical shocks.

Once you are familiar with the layout of the site and the location of the hook-ups, go ahead and pull in your vehicle. Do not hesitate to put your vehicle in park and look at where you are in relation to where you want to be. You can do this as often as you need to; there is no need be embarrassed and from what I understand, even those with a lot of experience may struggle to get their vehicle in the place where they want it.

Once you have pulled in your vehicle, you will want to make sure that it is level; you can use leveling blocks to help with this. Next, it is important to learn the exact amount of electricity available at the campground prior to running your appliances and it is best to do this before you plug in. Particularly in a full campground, there may not be enough voltage to go around and even when plugged in you may not have the full power you expect. It is recommended you carry a voltmeter with you, which can be plugged into one of the outlets. This will allow you to find out how much electricity is available.

Once your RV is level, and you know the amount of electricity available, it is time to begin the process of hooking up. First, it is best to turn off the electric outlet’s breaker switch. You will want to do this any time you insert or remove the RV’s electric plug in order to prevent shocks and not damage the plug. You will then plug in the electric cord, using an adaptor if necessary. Make sure, when plugging the cord in, that your hands and the ground are dry.

How Many Appliances Can I Use at One Time?

A big question that is sure to come up is exactly how many appliances can be used at one time. First, it is important to know how much power your appliances require. A good rule of thumb is that appliances that heat or cool will require the most power. Depending on brand and efficiency, the following will use between 10-15 Amps:

  • Air conditioner
  • Microwave
  • Electric water heater
  • Curling iron
  • Hair dryer
  • Space heater

The following will use between 5 and 9 Amps:

  • Coffee pots
  • Electric frying pans
  • Refrigerators
  • Toaster

The following will use 3 or less Amps:

  • TV
  • CD/DVD Player
  • radio
  • Fan

source : campingandcaravanningclub

It is amazing to me that a curling iron requires more Amps to operate than the refrigerator! Once you know how much power you have available, and how much power the items you want to use require, you will be able to determine how many items you can run at the same time. Should you plug into a 15 or 20 Amp power source, even if your RV has 30 Amp capabilities, you will be limited to 15-20 Amps. You will want to be careful when running your appliances as it is possible to damage them if they don’t get the amount of Amps they need to run properly. If you are using too many Amps, the RV will trip a breaker in the distribution box. Should you have 50 Amp capability and are plugged into a 50 Amp outlet at the campground, you will likely be able to run most of your appliances at the same time. With 30 Amp capability, you will have to be more selective about which appliances you run at the same time.

How to Avoid Draining your Battery

It is easy to inadvertently drain your coach battery when you are not even using the RV. Some items that will use up your power that you might not think about are the following:

  • TV antenna booster
  • Gas leak detector
  • Clocks in radios
  • A 12-volt light left on by accident

Some RV’s have a battery disconnect switch. If your RV does not have one, you can purchase this from an RV dealer. This can be installed on the battery post. With this device, should you not be using your RV or not need the coach battery, you can easily raise the lever which will disconnect the battery.

Ready for an RV?

While I am not going to run out and make an impulse purchase, I feel must better about my knowledge regarding electrical hook-ups and I am excited about continuing to build my knowledge. This is a whole new area for me to explore and learn about. One thing I read several times in my research is that should you be struggling, other folks in the RV community will be happy to help answer questions and provide guidance. This is a great opportunity not just to learn but to meet people who share a similar interest. I am going to keep this in mind, particularly as I move toward learning about water and sewer hook-ups.

Operating an RV is exciting and would be a whole new adventure. I am just hoping that there are no math formulas involved in learning about the water and sewer hook-ups!


Ilyssa is a mother of four who is employed full-time as a grant writer and who enjoys writing freelance articles in her spare time. Ilyssa has a great love of adventure and the outdoors, which she hopes she is passing along to her children. Last summer Ilyssa and her family took a five week road trip, camping and exploring most of the western United States. The trip inspired Ilyssa to work towards achieving flexible employment and/or financial freedom, so that she and her family may continue to travel and explore all nature has to offer, and not just for a few weeks out of the year.