RV Outlet Mounting Height Requirement

[chasfm11]

I'm on the last stages of finishing a new building for our RV. My next mission is to mount an outlet inside for it. I've decided on PSC13HR (CT. Electric) for the box setup. I've gotten the wire size for the run (#6 according the the calculators and due to the length) and now I'd like to be sure how high it has to be mounted.

This is a metal building with horizontal members that are used to fasten the outside sheeting. Left to my own ideas, I'd mount the box on a home made bracket fastened to the underside of one of those horizontals, placing the outlet about 3-4 feet off the concrete floor. I'd really like it to be lower, so that the cord is less of a trip hazard but I'm not sure I could secure the box well enough at that height. When I mounted the meter base, I had to reinforce the mounting points inside but I don't want that kind of hardware showing through the outside of the building where this box will be located.

Any guidance would be appreciated. I'd like this to be able to pass current NEC if it had to.

Thanks,

Charlie

[John Hilley]

In garages receptacles should be a minimum of 18" from floor. I usually make a plywood backer board. Can you install a plywood from horizontal bracket to floor?

[chasfm11]

Quote:

Originally Posted by John Hilley In garages receptacles should be a minimum of 18" from floor. I usually make a plywood backer board. Can you install a plywood from horizontal bracket to floor?

I guess anything is possible. I'd have to "shoot" the floor with one of those nail guns to have any place for the bottom to get a grip.

From your description, my 3 foot height is OK. I've had an outside outlet installed for the past 5 years for this RV and it was at about 10". I had it just high enough that any water underneath wouldn't have been a problem. I figured that wouldn't have passed muster but it wasn't visible to anyone but me. This one will be seem as soon as you come into the building.

Thanks for your response.

Charlie

[RV Wizard]

Charlie, if you do not have a nail Gun capable of shooting into the concrete, you could drill holes with masonry bit and install shields to accept a screw through a pressure treated 2 x 2 backer. Then attach your plywood to horizontal beam and this floor mount. Keep it high enough to allow for a Surge Guard if you have one.

[Gary RVRoamer]

You may not need to fasten the backer at the bottom - just let it rest on the floor. Fasten it at the top as you planned and through the back as well (to the sidewall - may need a spacer).

[Clay L]

I have used the latest generation (3rd or 4th?) construction adhesive to attach a 2 X 4 to cement and it held really well. I was not able to break it loose. I did clean the cement first.

[John Hilley]

Quote:

Originally Posted by RV Roamer [Gary] You may not need to fasten the backer at the bottom - just let it rest on the floor. Fasten it at the top as you planned and through the back as well (to the sidewall - may need a spacer).

This is true, if you can get two rows of screws into the horizontal member a spacer is probably all you need at the bottom.

[EngineerMike]

IIWMI'd mount the box on a vertical piece of strut, now available at most home improvement stores. It comes solid, w/holes in the back strap, even in stainless steel if you are made of money. You can buy ready made "foot" and angle ends that will give you needed bolt offset holes and other attachment forms. And you could assemble a whole strut framework that can be used for whatever other purposes might apply (hanging cord(s) and other RV related junque?).

At the base, use a masonry bit to drill a coupla holes for Tapcon or similar screws to hold the foot solidly to the concrete slab. A fresh slab should be easy to drill, especially if you have a hammer drill. These concrete screws are also found at HD or Lowes, and come in Phillips or hex head (and even in stainless steel for those made of money, but the blue paint holds up fine for any purpose I've used).

[chasfm11]

Thanks for all of the suggestions. My plan was to attach the top of the back of the box to the side of the "girt" using two self drilling screws. If it felt too unstable, I was going to fashion an "L" out of steel and fasten it to the bottom rear of the box and to the underside of the girt. I really wasn't worried about the stability or it staying in place.

The horizontal girts have a surface area of 4" high. Here is a picture (taken during construction)