Do you have a 30 amp shore power shore cord? If so, odds are you have a wall switch inside the RV somewhere that turns the power to that receptacle on and off. Usually on RV's that have this it switches 120 power between either the 120 side of the water heater and fireplace or the Microwave power and the fireplace. 50 amp RV service will not have this type switching system. The outlet connector you have in the pic is how they splice 120 romex wires without using a receptacle box and wire nuts. They also use them for when you connect a Romex to a round 120 3 wire sheathed cable that looks like a appliance wire cable. Doug