I've never used a forum before but here goes. I mounted a 100 AMP Square D dual lug (see attached photo)(has room for 6 breakers) on the front of the trailer with 40' of 10/3 SOOW wire running to the pole with an RV plug. The wiring has a black (hot), white (neutral) and green (ground) wire. With it being a dual lug box, I know the the black wire goes to one lug and green goes to ground bar. So where exactly does the white wire go and do I need an additional grounding bar? How do I get power to the other lug? I'm only needing 110V service throughout the living quarters. Hopefully I don't sound like too much of an idiot but I need to be sure.

I have an older house dated back to 1950s where the wiring was done in clothed romex with only two conductors (no ground). At some point the property had a renovation, and the newly renovated areas (kitchen, garage and bathrooms) have been rewired properly with EMT acting as EGC. But the original bedrooms, and a living room are still wired poorly. By poorly I mean whenever I open up a metal box for a receptacle, I see the white neutral conductor from the cloth romex inside the box with a short section of the insulation removed, and wrapped around the metal box's grounding screw before connecting to the receptacle's neutral screw. I understand lack of a complete rewire job, my best option is to identify the few circuits wired this way, and install GFCI receptacles instead. If I can find the first receptacle in a series easily, I can just install the GFCI there and the downstream receptacles would be protected. So please look over my plan of attack. (1) Identify the circuits still wired with those old clothed romex and all the receptacles and switch boxes. (2) Open all of these boxes up and disconnect the neutral conductor from the ground screw on each metal box. Slide on a short piece of white heat shrink tubing onto the short exposed section of the neutral and repair the insulation. (3) For each receptacle on the same circuit, find the most upstream receptacle, replace it with a GFCI receptacle, and move the downstream conductors to the load side of the GFCI. I don't know if there is an easy way to find the most upstream receptacle other than trying to disconnect each one and see what happens at the other receptacles? Is there? (4) Find the switch boxes and junction boxes and if the neutral conductors for those circuits are connected to the box disconnect them. Now, instead of using GFCI receptacles, what if I changed the breakers for those to GFCI breakers? Would that be less work? I still need to open up every box right?