I am wondering if you can share the Wht / neutral & the bare copper / grd using the Blk for one circuit and the red for a second circuit? Or does code require you have 2 14/2's from the E Panel to each circuit not sharing the neutral & Grd?
A friend got some 14/3 for a project and ran it not knowing it was a 14/3 and he does not want to pull out it and rerun the wire with 2 - 14/2's. He asked if he could just continue the second circuit with the Red and share the Wht & Grd and meet any code requirements.
Told him I was not sure but would ask and see what I could find out.
Any information would be great to know.