Test & Measurement

Tip of the Week: The Basics of Chapter 5 in NFPA 70 (NEC)

Nov. 16, 2015

Become familiar with the section of the code that addresses special occupancies

The first four chapters of the NEC apply to all installations, except as modified by Chapters 5, 6, 7, and 8.

Upon first glance, Chapter 5 [Special Occupancies] may seem overwhelming — especially if you’re trying to find the requirements for a particular hazardous location. And if your occupancy isn’t a hazardous location, do you have to wade through the whole chapter to make sure it’s not in there?

Fortunately, there’s a logic to how this chapter is arranged. You can divide it into themes that put related Articles (similar occupancies) together:

Hazardous locations [Articles 500 through 510].
Places having to do with car/aviation fuels and paint-type solvents [Articles 511 through 516].
Health care facilities [Article 517].
Places that may be densely packed with people (theaters, amusement parks, circuses, motion picture studios) [Articles 518 through 530].
Motion picture projection rooms [Article 540].
Specific types of buildings and vehicles and related locales (manufactured buildings, agricultural buildings, mobile homes, RVs, floating buildings, marinas) [Articles 545 through 555].
Temporary installations [Article 590].

Of course, you can just use the Table of Contents to see if your occupancy is listed. So why care about the themes?

For one thing, understanding the themes may be useful to examine the requirements for a similar occupancy to help determine the intent of a particular requirement that seems unclear.

Also, what if your type of occupancy isn’t specifically listed by name? If you understand the themes, you can more easily place your occupancy in the correct article. But perhaps the best reason is that understanding the themes means you won’t feel overwhelmed when turning to Chapter 5. It’s all arranged logically. Now you know the logic behind the arrangement.

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.