wiring a 30 Amp Power Outlet 30A Circuit Breaker {{UPDATE}}

It really doesn't hurt anything to just plug in your RV without switching off any breakers. If there is already a 30 amp outlet on the side of your house, I wouldn't do a thing other than use it. If it bothers you to plug and unplug your rig with the circuit live because you think you will somehow damage something in the RV, just switch off the main breaker in your RV before you plug or unplug, exactly the same as flipping off the an outside breaker. That way you don't have to buy anything or wire anything up.