Commonly misunderstood/misapplied terms, part 2.

  • AHJ (Authority Having Jurisdiction). Contrary to a widely held misperception, the AHJ may be someone other than the electrical inspector (who perhaps hasn't set foot in your facility since it was built). In fact, your facility may have multiple AHJs, any one of which can shut it down. For example, your insurer's representative inspects your facility and finds problems. If your facility doesn't meet certain requirements within a specified time, it won't be insured while operating. If your company leases its building, the owner is also an AHJ.
  • Building. The NEC often says, "…building or structure." What's the difference? A building is a type of structure, but a structure is not a type of building. A building stands alone, or it's cut off from adjacent structures by fire walls (with all openings protected by approved fire doors).
  • Conduit. Conduit is an enclosed wiring method, but not all enclosed wiring methods are conduit. Electrometallic tubing (EMT) is often erroneously called conduit. If you look in Chapter 3, you'll find various wiring methods — each with its own article.
  • Conduit body. Interestingly enough, not just conduit systems have conduit bodies; so do tubing systems (e.g., EMT).