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National Electrical Code Articles and Information

Based on the 2020 NEC

by Mark Lamendola

National Electrical Code Top Ten Tips: Article 600, Electric Signs and Outline Lighting

  1. While Chapter 5 is arranged thematically, Chapter 6 is not. Therefore, you don't have the equivalent of Article 500 that lays the basis for several other Articles. Instead, Chapter 6 just starts off with a fairly arcane topic.
  2. Article 600 covers the installation of electric signs and outline lighting [600.1], regardless of voltage. Don't confuse outline lighting with outdoor lighting, though outline lighting may be outdoors.
  3. You'll find the definition of skeleton lighting in 600.2. While normally any electrical equipment you install must be listed for that particular use, the listing requirement does not apply to skeleton lighting when field-installed per Article 600 requirements [600.3(A)].
  4. If outline lighting consists of listed luminaires and you install it per Chapter 3 requirements, it's redundant to have the outline lighting assembly itself listed. So, listing isn't required [600.3(B)].
  5. When you calculate branch circuit sizing for the systems, you must consider them to be continuous loads [600.5(C)]. That does not preclude diversity calculations, but if doing those keep in mind the hours of operation.
  6. Each installed system must have a disconnect that opens all ungrounded conductors and controls no other load [600.6].
  7. Article 600 uses the word "grounding" incorrectly (see Article 100 for definition, see Part V of Article 250 for more info). Do not ground these lighting circuits. The intent here is that you bond them. When reading 600.7(A), just substitute "bond" for "ground" and follow the requirements. The reason for the language misuse is we are still incorrectly referring to equipment bonding conductors as equipment grounding conductors. The idea here is that 600.7(A) applies to the bonding connections. Don't connect the green wire to a ground rod or to building steel; connect it to the equipment "grounding" (bonding) conductor.
  8. While 600.7(A) provides the requirements for bonding the signs, 600.7(B) provides requirements for bonding everything else.
  9. Just as people often confuse temporary power with "lax requirements," they often have that same confusion with portable and mobile signs. Note that these do require adequate support [600.10(A)] and must meet the other requirements of 600.10. Apply common sense is generous serving sizes....
  10. The requirements for LED lighting are new with the 2011 NEC, and you will find them in 600.33. This does not refer to LED per se, but LED systems are Class 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.




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