What is the proper way to leave unused nonmetallic sheathed cable inside walls or ceilings?

Question

The question pretty much sums it up. I nailed through a live wire in my ceiling. Rather than splice it and install a jbox, I ran a new run to the outlet. However, I took a slightly different route that did not require any additional cuts into the drywall.

I will be leaving the dead run in the ceiling. Are there any guidelines or code I need to follow to still be within compliance? For example, do a cut the wire ends clean? Tape them up and label them? Also, do I need to remove the dead wire from the outlet box or can that be cut and/or taped up?

Answer 1

It's acceptable to leave wire in the walls. The only thing you need to do is leave the ends exposed in boxes and wire nut and tape the two legs together. That will indicate to an electrician what's going on, and if someone does try to tie into them in the future it will just pop the breaker.

Answer 2

There's nothing in National Electrical Code about removing abandoned electrical cable. If it's communication, television, radio, etc. cable, you have to remove the accessible portion of the cables. If it's wire in a raceway (conduit, cables trays, etc.), you do have to remove it.

Connecting the ungrounded (hot), grounded (neutral), and grounding conductors together is a common practice (one which I've recommended before). However, it relies on the breaker functioning properly, in the event the line is ever energized in the future. The safer practice is to cap each wire separately, and label the wires as abandoned at both ends.