By Mike Holt for EC&M Magazine
Q1. I have heard that unused wires must be removed unless they are tagged for future use. My plant has lots of unused conduit runs with the old feed wires taped up in the panel. Is there some where in the code where it says these runs should be removed? It is starting to look like a spider web in some spots.
A1. The NEC does not require unused power and lighting conductors be removed, except for cellular and underfloor raceways [372.13, 374.7, and 390.7].
However, the accessible portions of abandoned low-voltage and limited-energy cables shall be removed. According to Chapters 7 and 8, abandoned cables are those that do not terminate at equipment and are not identified for future use.
That was dated 2004, so it was based upon the 2002 NEC.
I've seen 800.52 referenced in regards to removing abandoned comm. cables, but that article was dropped in 2008 (or so it appears to me. 2008 code skips from 800.50 straight to 800.53.
220/221, maybe you were thinking of comm. cables?
Though I could have sworn someone on this forum mentioned that abandoned line-voltage electrical cables would have to be removed. Don't remember if code was cited, though.
PS - The removal of comm. cables is to reduce flammable materials and noxious gases released from the cables during combustion. It has nothing to do with electrical safety.