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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 605, Office Furnishings

  1. Article 605 is one of the shortest articles in the NEC, weighing it at almost exactly two pages. It's also commonly overlooked. Many tenants or owners will hire temps or a contract labor firm to install their office furnishings, under the mistaken idea it's all plug and play.
  2. Many modular office systems, and their furnishings, have electrical equipment, lighting accessories, and wiring systems. These are used to connect, or are contained within or installed on these modular office systems and/or office furnishings. When they connect, or are contained within or installed on office furnishing systems, they are covered by Article 605 [605.1(A)].
  3. Article 605 applies to systems, not individual furnishings [605.1(B)].
  4. So, what is an office furnishing? I mentioned modular office systems previously, and that term is often used to mean office furnishings (though the NEC does not use this term in Article 605). When you see a cubicle farm, it's made of dozens of cubicle walls and those are typically prewired for data, receptacle power, and lighting. This is one type of office furnishing covered by Article 605. Similar to them, in the sense of being prewired (and thus needing to be correctly connected to branch circuit power and limited in number per circuit to prevent overload) are workstations, desks, shelving systems, and storage units that include electrical and mechanical interconnection [605.2],
  5. A wired partition cannot extend from floor to ceiling [605.3]. The main reason for this is it would create a room that is cut off from the surrounding space; this has implications for the spread or containment of fire and smoke, not to mention detection of same. The AHJ can permit a wired partition to extend from floor to celiing, but in not case can it penetrate the ceiling. If you desire floor to ceiling partitions, stop to consider what flaw in your office management would make this seem necessary. Cubicles already isolate people enough, without giving them the dignity of an actual office. If the problem is people need more privacy or insulation from noise such as phone conversation, you need to consider that there are other solutions that may be better than basically shoving people into closed cardboard boxes.
  6. All the wiring must be contained within the wiring channels, and those channels must be free of projections or other conditions that could damage the conductors [605.4]. For example, it's not acceptable to run conductors along the surface of a partition (even if you do cover them with duct tape!). An electrician will know not to do this, but unqualified installers have done exactly that. Wireways not only keep wiring neat, they provide mechanical protection of the wiring.
  7. For electrical connection between office furnishings (in context of these systems), use a flexible assembly identified for use with office furnishings [605.5]. Alternatively, you can use flexible cord. But it must meet all four conditions of 605.5(1) through (4).
  8. Lighting accessories must be securely attached or have a means of support [605.6(A)].
  9. Receptacles are not permitted in lighting accessories [605.6(C)].
  10. Office furnishings may be fixed (secured to building surfaces), in which case they must meet the requirements of 605.7. Or they may be freestanding, in which case they must meet the requirements of 605.8 or (if cord-connected) 605.9.

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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