Understanding Article 100 of the 2023 NEC: Definitions
Introduction
The 2023 National Electrical Code (NEC) introduces a comprehensive approach to the use of definitions within the code. Article 100 has been specifically designed to include definitions that are essential for the application of the code, ensuring clarity and uniformity across various electrical installations and practices. This article aims to explain how definitions are now utilized in the new 2023 NEC, highlighting the significant changes and the importance of understanding these definitions for proper code application.
Scope of Article 100
Article 100 contains definitions that are crucial for the correct application of the NEC. It is important to note that this article is not meant to include commonly defined general terms or technical terms that are commonly defined in related codes and standards. Instead, it focuses on terms that are specific to the NEC.
Key Features:
- Essential Definitions: Only definitions essential to the application of the NEC are included.
- Specificity: General and commonly defined technical terms from related codes are excluded.
- Article-Specific Definitions: Definitions that apply only to a specific article are followed by the article number in parentheses.
Informational Notes
Definitions followed by a reference in brackets are extracted from other NFPA standards, with only editorial changes made to ensure consistency with the NEC. These standards include:
- NFPA 30A-2021: Code for Motor Fuel Dispensing Facilities and Repair Garages
- NFPA 33-2021: Standard for Spray Application Using Flammable or Combustible Materials
- NFPA 75-2020: Standard for the Fire Protection of Information Technology Equipment
- NFPA 79-2021: Electrical Standard for Industrial Machinery
- NFPA 99-2021: Health Care Facilities Code
- NFPA 101®-2022: Life Safety Code®
- NFPA 110-2019: Standard for Emergency and Standby Power Systems
- NFPA 303-2021: Fire Protection Standard for Marinas and Boatyards
- NFPA 307-2021: Standard for the Construction and Fire Protection of Marine Terminals, Piers, and Wharves
- NFPA 499-2021: Recommended Practice for the Classification of Combustible Dusts and Hazardous Locations for Electrical Installations in Chemical Process Areas
- NFPA 501-2022: Standard on Manufactured Housing
- NFPA 790-2021: Standard for Competency of Third-Party Field Evaluation Bodies
- NFPA 1192-2021: Standard on Recreational Vehicles
Enhanced Content and Style Manual Revisions
The NEC Style Manual revisions have centralized all definitions into Article 100, reinforcing its significance. According to section 2.2.2 of the revised NEC Style Manual, all definitions must reside in Article 100, which cannot be subdivided. Definitions specific to one article will have the article number in parentheses, ensuring users know the scope of each definition. If a definition is not article-specific, it applies throughout the NEC.
Key Points:
- Centralization of Definitions: All definitions are now located in Article 100.
- Non-Subdivision: Article 100 is not permitted to be subdivided.
- Article Number Indication: Definitions specific to one article include the article number in parentheses.
- General Application: Definitions without an article number apply across the NEC.
- Code Making Panel (CMP) Responsibility: The CMP responsible for each definition is listed at the end of the definition.
Importance of Understanding Definitions
The NEC does not define every term used within the code. General terms are found in nontechnical dictionaries, while some technical terms are defined as per the Institute of Electrical and Electronics Engineers (IEEE) 100, The Authoritative Dictionary of IEEE Standards Terms. It is crucial for professionals to understand that many terms in the electrical trades are registered trademarks for specific products, and such trademarked terms are not used in the NEC or its handbook.
