The NEC doesn’t allow you to use equipment or conductors unless they are “approved” [110.2]. Article 100 defines “approved” as “Acceptable to the Authority Having Jurisdiction.”
What does this really mean? How does it affect your work in a plant?
First of all, it doesn’t mean you need to send the AHJ a bill of materials and/or samples for inspection to get approval to use those materials. The AHJ generally doesn’t do the ac