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How Do I Wire an RV Electrical Service?

To wire an RV hook-up and service to accommodate an RV you must put some thought into the pre-planning.  This article reviews the factors that need to be taken into consideration for successfully wiring an RV service.

A number of factors to be taken into consideration which will determine the wire and breaker size needed to power your RV hookup sufficiently.

Q: I would like to run a 30amp and/or 50 amp service approximately 120′ from entry service to accommodate  a RV motor home.

What gauge wire should be used?  What amp breaker?


Due to the length of this run (120 feet.), to get a full 50A service at 120V, you would have to run #4 AWG copper wire to stay within acceptable voltage drop (3%).

You would use a 50A breaker to feed this circuit.

To get a full 30A 120V service, you would require #6 AWG copper, fed with a 30A breaker to stay within the 3% voltage drop.

If you plan to use the R.V.’s full electrical system then this is what you are going to need:

If you only want to have the use of the lights, and keep the battery charged, and don’t need the heavy loads such as A/C or washer/dryer, etc., then you could run a smaller service that would be considerably more cost effective. Then you would use the appropriate wire size and breaker.

You would then need the approved adapter to plug the unit in, and would have to disable the heavy loads by unplugging them or shutting off and labeling the breakers with a note that the electrical supply is not sufficient to run the heavy electrical loads.

– Terry Peterman, the Internet Electrician

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  • Fridaywill

    what factors need to be taken into consideration when adding a large load to an existing service?

    • Runejunkie

      Fridaywill. Large Load, Need to make sure that your wiring is large enough to run the load. Don’t just change out a Breaker to a larger size if the Wire that it is running down can’t take it.

      What kind of Load are your talking about? Like a120v, 20amp Breaker with the right wire can run 2400 WATTS. Take the Volts times the Amps breaker to get the total Watts that you can run.
      @5b3fecde2a99269d3764181728f5f24b:disqus If it is a 240V service on a 50amp Breaker it could take 12000 watts. Hope this helps and Good luck. When in Doubt Hire it out.

  • Ken Franks

    I presently have a 30 amp RV outlet installed at my home.  I want to install a 50 amp RV service.  I have electrical background, though not licensed.  My concern is that I’ve recently read that a problem exists at some RV parks that cause extreme problems with the RV units.  It has something to do with the proper grounding or something that can cause a fire or total wipe-out of the RV’s electrical system and appliances.  Can you clarify the problem and steps to avoid the problem?

  • Runejunkie

    You need to make sure you have the right wires running to your 50amp service outlet. You Set up the 50amp outlet the same way you would with any other 125/240 outlet like to your Dryer or Range. With Background in Electrical then you shouldn’t have any issue doing so. The issue your talking about is people that are installing a 50amp 240 service  off a 125volt service. What people don’t understand is that you can’t do this right off a single leg of your main panel. 240volt come from a double leg off the right and left side of your main. In in Doubt Hire it out.

  • Cuttman80

    All though this would work do the math yourself this guy is trying to over kill it. Aluminum is fine for that length but if your asking these kind questions then maybe you should hire it out and use these as guide lines to check the work of the person you hire.

  • When my neighbor was rewiring his RV he used a smaller service to conserve energy and he ended up regretting it; he didn’t have the option of using all of his appliances. Later he had an electrical service company come and professionally wire the RV with a larger amp service so he could use the lights and TV at the same time.


The Basics of Household Wiring DVD

"If you're looking for a good reference to help you understand simple home wiring, I personally recommend 'The Basics of Household Wiring' DVD".

Terry Peterman, the Internet Electrician
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