I'm embarking on a re-wiring of my Garage/Workshop. I've identified 3 new circuits I'm adding. I have a large roll of new 12-3 wire, which I'm looking to use up in this project. After completing the wiring I'll be insulating and covering the stud-bays.
I am thinking of running two pulls of 12-3 while I've got easy access, and leaving one of the extra hot wires unconnected (capped), in the box, for when I get around to re-doing my pantry (shares a wall) and want to add a grounded outlet. Running an extra 12-2 would mean putting another hole in each stud along the wall, and I've already got 2 holes in each (50's house with many partial-remodels), I don't really want to turn the structure into swiss cheese.
I have not been able to find anything in the code about leaving one of the wires of 12-3 unused. Do you think an inspector would balk at this? My city uses the most recent version of the NEC code.
I know a 12-3 run needs a double-pole breaker because of the shared-neutral, but what about my theoretical extra wire (with one live circuit, but will eventually require a shared neutral)? Do I just need to run the circuit and wire a dummy outlet? I'd rather not unless necessary.
Best Answer
There's nothing in the code that says you can't pull unused wire. In fact, since it's not technically connected to the electrical system, NEC probably doesn't apply at all.
Just keep in mind that garage receptacles will require GFCI protection, while a receptacle in a pantry would not.