Understanding General Requirements of the NEC, Part 14
Article 110 provides general requirements for all installations. Part II provides the requirements for systems operating at 1,000V (nominal) or less. Section 110.26(E) covers dedicated equipment space. All service equipment, switchboards, switchgear, panelboards, and motor control centers must be located in dedicated spaces and protected from damage.
This gives rise to the question, “What is a dedicated space?” A common misperception among office managers and production managers is that the electrical equipment is relegated to specific places, which may also be used for storage and other purposes. They flip the definition on its head, making dedicated spaces for their equipment and operations with some leftover available for the electrical equipment and whatever else they care to put there. Thus, you find a flowerpot on top of a filing cabinet in front of a breaker panel in an office, file boxes stored in a transformer vault, and pallets sitting in front of a motor control center.
The word dedicated, however, means there’s no other purpose for that space. It’s off-limits to the filing cabinets, pallets, and so forth.
The requirements stated in the NEC are repeated in the OSHA regulations, specifically 29CFR 1926 Subpart M. It’s common for electrical engineers, maintenance managers, and others with electrical backgrounds to argue for dedicated space by referring to the NEC. A common retort to that is something along the lines of “We aren’t under the NEC.” But nobody can credibly say, “We aren’t under OSHA.” So go ahead and use the NEC to ensure you have adequate space around equipment, just emphasize that OSHA provides identical requirements.
For indoor and outdoor equipment, the dedicated space for the electrical installation is equal to the width and depth of the electrical equipment and extends from the floor to a height of 6 ft above the equipment or to the structural ceiling (whichever is lower) [Sec. 110.26(E)(1)(a)]. A dropped, suspended, or similar ceiling is not a structural ceiling [Sec. 110.26(E)(1)(d)].
The area above the dedicated space is allowed to include foreign systems, including sprinkler systems, if protection is installed to avoid damage to the electrical equipment from condensation, leaks, and so forth [Secs. 110.26(E)(1)(b) and (c)].
Also, outdoor equipment must be:
- Installed in identified enclosures.
- Protected from accidental contact by unauthorized personnel or vehicular traffic.
- Protected from accidental spillage or leakage from piping systems.
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.