I installed a 120V 30A outlet for an RV hook-up. I fed it with a #10/3C w/G for the option of changing the outlet to 240V 30A for a welder or EV charging. Until I install the optional 240V outlet, can I connect the one hot wire for the 120V outlet to one pole of a 2-pole breaker to feed the 120V 30A outlet?