Doug, he mentioned that his current wiring is protected with "dual 50A breakers", so that would suggest his wiring is exactly what is needed for a 50A RV connection.
Camperpug, if you don't mind spending a bit more money, perhaps you might consider installing a pedestal box which includes the 50A/30A/20A breakers & receptacles all in one. Very handy, it bypasses the need for the adapters, the breakers are "right there", I find the 20A GFCI outlet handy when working around the RV and if you ever upgrade to 50A, you're all set. Something like this
50A/30A/20A RV Power Outlet Box. I can't vouch for that specific company, but I've installed 4 similar units and no problems with any of them.
If you decide to use the 50A male to 30A female adapter, get one of the "dogbone" types and you should be good. They're good to have on hand anyway. Something like
this from Camping World.
Good Luck,
~Rick
