National Electrical Code Articles and Information
National Electrical Code Top Ten Tips: Article 410 -- Luminaires, Lampholders, and Lamps
by Mark Lamendola
Based on the 2017 NEC
Please note, we do quote from copyrighted material. While the NFPA
does allow such quotes, it does so only for the purposes of education
regarding the National Electrical Code. This article is not a substitute
for the NEC.
These are the 10 NEC Article 410 items we deem most important, based
on the pervasiveness of confusion and the potential costs of same.
- You may need to comply with more stringent requirements for
lights than those contained in Article 410. For example, if the
illumination equipment is in a hazardous location, apply Articles
500 through 517.
- No luminaire can have live parts exposed to contact [410.5].
- If the location is anything but clean and dry, use a luminaire
rated for that environment. Details of what to use where are in 410.10.
- Clothes closets have special requirements [410.16]. Follow them
carefully. This is a key area for inspection failure. Also, DIY
homeowners try to "improve upon" existing closet lighting and create
a fire hazard. If you are doing residential electrical work, make a
note of closet lighting conditions and make the homeowner sign off
as being aware of any violations you find.
- With dimming controls and other nice additions to today's
lighting systems, a common code violation is insufficient box size.
Canopies and outlet boxes must be of sufficient size so as not to
crowd the conductors [410.20].
- You cannot leave open outlet boxes in a luminaire installation.
Ensure the box is covered with a canopy, lampholder, receptacle, or
similar device [410.22].
- Secure support of the luminaire is essential. Improper support
is a leading code violation in luminaire installations. Don't use
the screw shell of a lampholder to support any fixture weighing more
than 6lbs [410.30(A)].
- You can use an outlet box to support a fixture [410.36(A)].
- You cannot mount luminaires into ceiling tiles (using them as
support). Luminaires must be supported by frame members [410.36(B)].
- All exposed metal parts must be bonded (NEC says grounded, but
means bonded--see Article 100 definitions), unless you insulate them
from all metal surfaces (which is normally not practical) or they
are inaccessible to unqualified personnel (meaning the NEC allows
you to present a risk to qualified personnel, even though it's best
not to do so for any personnel). See Part VI of Article 410, but also Part V of Article 250.
How the NEC is arranged
- The first four Chapters of the NEC apply to all installations.
- Article 90 precedes Chapter One, and establishes the authority of the NEC.
- Article 80 follows the body of the NEC; it exists as Annex H. It provides the requirements for administration.
- Chapters 5, 6, and 7 are the "special" chapters, covering special: occupancies, equipment, and conditions (in that order).
- Chapter 8 provides the requirements for communications systems.
- Chapter 9 provides tables.
- The appendices provide mostly reference information.
- 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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