I know this has been discussed before but I have a customer that needs a 50 amp RV receptacle attached to a detached building. Not sure if it needs GFCI protection from the panel or if I can use a RV panel that has GFCI protection and would that serve as a disconnect as well or would it need a disconnect beside of the RV panel? And if a disconnect is needed, could a breaker lock in the panel serve that purpose?