Electricians in the field may wonder what to do when they come across an NEC violation. The answer really depends on the type of work.
New installations — New installations must comply with the NEC [80.9(A)], so you must resolve any violations. But which NEC edition should you use? Each jurisdiction adopts its own rules on this. Typically, the rule is you use the edition of the NEC that was current (in that jurisdiction) when the building permit was issued. The rationale is that the permit was issued based on drawings complying with the NEC at that time. Many jurisdictions specify an earlier edition of the NEC than the current edition. Always check with the AHJ on which revision to use.
Existing installations — The NEC doesn’t hold an electrician or electrical company responsible for violations committed by somebody else [80.9(B)], just because you visit the site (for example, to bid on a job). If you find violations, document them. The electrical services company should submit a report to the owner. If the violations are severe enough to pose an imminent danger, and the owner balks at bringing the facility into compliance, walk away from the job. For example, it’s not that big a deal if you see a few enclosures with open knockouts, but it’s a very big deal if you see raceway being used as the neutral for the 277V lighting, or if you see parallel feeders that are two different wire gages.
Additions, alterations, or repairs — The part that you work on must comply with the NEC [80.9(C)]. As with an existing installation, you’re not accountable for what you haven’t worked on. If the violations aren’t terribly serious, document them and discuss with the owner. This could, and should, lead to remedial work designed to bring the facility up to Code. But if the violations may pose an imminent danger to occupants, inform the AHJ and let the AHJ decide how to proceed. In no case should you work in a location where Code violations present a danger to you. If an owner refuses to correct violations so that you can safely perform your job, walk away.