30 to 50 Amp "shorelines" aren't uncommon for motorhome. The bigger their land yacht, the more power they typically use.

At 100 feet I'd be inclined to size up to 6 gauge just so the voltage drop if they actually pull 30A isn't a problem.

Thanks, originally I was going to install a 50 amp breaker with 6 gauge, but I got the 8 gauge free. I need to see if I can get some 6 gauge like that. It would not hurt to have it oversized for the reqiured power. The motorhome would have it's own breakers to handle it if they overloaded a circuit inside.

RV circuits can easily get you into trouble if you are not sure what you are doing, a 50 amp hookup will take 4 wires and 240 volts but a 30 amp hookup is only a 3 wire 120 volt circuit. On all but the biggest of movie star type motorhomes all of the loads are 120 volts, and a normal RV with a 50 amp hookup utilizes the incoming 240 volts as two 120 volt lines. Seen more than one RV get fried by someone running 240 volts into a 30 amp TT hookup.

So legally you can only use a 30 amp breaker on your #8s if you are connecting directly to a 30 amp TT receptacle. About the only way you can cover all the bases is with a special RV panel which would contain a 20,30 and 50 amp receptacle with circuit breakers.

What type of wire are you using, I assume it will be underground?

This post was edited by joefixit2 on Mon, Feb 10, 14 at 20:57

The common way to do it is to install a L21-50R (50A 120/240 receptacle) and make some adapters that mate to whatever RV's you are expecting.

This is how we do it here.

This post was edited by joefixit2 on Mon, Feb 10, 14 at 22:45

"What type of wire are you using, I assume it will be underground?"

I have some armored direct burial cable I got free. I will check with my friends and see which plug they need and wire it accordingly.

The friends may already have some adaptors that they keep in the RV, but beware, they may be ill-advised.

If you don't know what you will be using and possibly have different things the post "Posted by joefixit2 9 on Mon, Feb 10, 14 at 22:40"
is BY FAR the best way to go.

That does look pretty slick. It could be very convenient if your RV camp is going to get a lot of use. How much do they cost? It must qualify as a sub panel from the look of it.

For some reason, it reminds me of a 240V (think air conditioning) disconnect that doubles as an outdoor, 120V, GFI outlet.