I had a coil of cable in my attic that I pulled through to a light switch. Is there any danger with a twisted wire, or multiple wires that twist around each other in a wall?
2 Answers
There are no requirements to not twist the wire, and this is especially difficult to ensure when fishing wire without staples as allowed in “old work” installations.
To fully answer the general question though, if you have access to an exposed cable and are securing and supporting every 4.5 ft and within 12” of every junction boxes as required, there is no reason to have excessive amounts of twisting in the cable.
If there is excessive twisting in a “new work” install with exposed wiring, it is unlikely but possible that some inspectors (representing the Authority Having Jurisdiction) may choose reject an installation as not workmanlike per NEC 110.12. Personally, if there is twisting underneath a lot of cable staples, I could see this as a valid reason for rejection per this clause of the NEC.
From NEC 2020
110.12 Mechanical Execution of Work
Electrical equipment shall be installed in a neat and workmanlike manner."
No requirement for it to be non-twisted. I would just ensure it is flat where you staple it.