My understanding of color coding allowed by NEC is:
- Ground: Bare, Green or Yellow/Green
- Neutral: White or grey
- Hot: All other colors
If I need to run 3 distinct circuits in conduit, I might choose:
- Ground: Green
- Of course, if I'm using metal conduit & boxen, I can skip the ground wire entirely and use the conduit for the ground.
- Hot: Black, Red, Blue
- Neutral: White, Grey, and ???
I can pair the White/Black and the Grey/Red, but what do I pair with the Blue to provide a neutral for it?
In thinking about this, I believe that a MWBC could be a way around this, but I'm not certain if that technically only applies to cable (i.e NM-B/"Romex"), or if MWBCs can be used in conduit-based wiring as well. Additionally, from what I've been reading here, there's a strong trend away from them, especially for GFCI/AFCI protected circuits since handle-tied *FCI breakers are somewhat unobtanium.
Note: This is purely a theoretical question. I do not have an actual application for this at this time. I'm simply trying to learn ahead of a home addition/remodel that's coming up.