construction code books

Home | Search | About us                  Bookmark and Share

nec training

National Electrical Code Articles and Information

Based on the 2017 NEC

by Mark Lamendola

National Electrical Code Top Ten Tips: Article 513 -- Aircraft Hangers

  1. Article 513 covers any structure used for storing or servicing aircraft containing Class I (flammable) or Class II (combustible) liquids whose temperatures are above their flashpoints [513.1].
  2. Article 513 does not cover unfueled aircraft [513.1].
  3. Article 513 provides four classifications of locations: Below floor level, Areas not cut off or ventilated, Vicinity of aircraft, and Areas suitably cut off and ventilated [513.3].
  4. When installing equipment in a location that is in, may be in, or may be operated in, a Class I location, comply with the applicable provisions of Articles 501 and 505 [513.4(A)].
  5. If the location isn't Class I but is a hanger, then you must install fixed wiring in metal raceways unless the area is "suitably cut off and ventilated." Alternatively, you can use Type MI, TC, or MC cable [513.7(A)].
  6. If wiring runs under or in the hangar floor, it must comply with Class I, Division 1 requirements [513.8(A)].
  7. You can't use standard cords for pendants. The flexible cord must be identified for hard usage or extra-hard usage. And it must have a separate equipment grounding conductor [513.7(B)]
  8. If a receptacle is in an area where it might be used for electrical diagnostic equipment, electrical hand tools, or portable lighting equipment, it must be GFCI-protected [513.12].
  9. 513.16(A) contains confusing language. The subtitle of 513 refers to grounding and bonding. What it means is bonding (see Article 100 definition). Nothing in this passage has anything to do with grounding. You accomplish nothing by grounding a raceway. What you want to do is bond it.
  10. Maintain the continuity of the bonding conductor (which, in the NEC, is incorrectly referred to as the equipment grounding conductor or EGC in direct conflict with Article 100 definitions) [513.16(B)(2)].

How the NEC is arranged

  1. The first four Chapters of the NEC apply to all installations.
  2. Article 90 precedes Chapter One, and establishes the authority of the NEC.
  3. Article 80 follows the body of the NEC; it exists as Annex H. It provides the requirements for administration.
  4. Chapters 5, 6, and 7 are the "special" chapters, covering special: occupancies, equipment, and conditions (in that order).
  5. Chapter 8 provides the requirements for communications systems.
  6. Chapter 9 provides tables.
  7. The appendices provide mostly reference information.
  8. Appendix D contains examples that every NEC user should study.

Try your NEC moxy:

  • Do you know the difference between bonding and grounding? Hint: Look in the NEC, Article 100.
  • Does the NEC refer to grounding incorrectly in any of its articles? Yes! So be careful to apply the Article 100 definitions. Don't ground where you should bond.
  • When doing motor load calculations, which Article covers hermetic motors? Answer: While Article 440 covers the application of hermetic motors, it does so only by amending Article 430 because hermetic motors are a special case of motors. For motor load calculations, refer to Article 430.
  • Does the NEC provide a voltage drop requirement? Yes! It does so in a special case, which is Article 648 Sensitive Electronic Equipment. But for general applications, it does not provide a requirement; it merely provides a recommendation in a couple of FPNs.
  • Take our Code Quizzes.

Remember other applicable codes, rules, standards, and references:

  • OSHA's electrical worker safety rules.
  • IEEE standards.
  • NETA standards.
  • NFPA standards.
  • International Codes (if applicable to the installation).
  • State Codes (if the state has them).
  • Local ordinances and permit requirements.
  • Local fire codes.
  • Manufacturer requirements or guidelines.
  • Customer security requirements.
  • Industry standards.
  • Your company's own internal standards, practices, and procedures.
  • Engineering drawing notes.



Codebookcity is a subsidiary of Mindconnection, LLC. If you have any questions, comments, or concerns, please write to sales @ We do want your business.