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Changes to the 2020 NEC

A rigorous process of review keeps the National Electrical Code® up-to-date with new technologies

Throughout the United States and around the world, NFPA 70®, National Electrical Code® (NEC®) sets the foundation for electrical safety in residential, commercial, and industrial occupancies. The 2020 edition of this trusted Code presents the latest comprehensive regulations for electrical wiring, overcurrent protection, grounding, and installation of equipment. In fact, more than 3,700 public inputs and 1,900 comments went into the revision of the 2020 edition of the Code. Hundreds of updates and four all-new articles pave the way to a safe and efficient electrical future.



How do I identify what has changed?

The 2020 NEC® includes revision symbols identifying changes from the previous edition. Text revisions are shaded. A Δ before a section number indicates that words within that section were deleted and a Δ to the left of a table or figure number indicates a revision to an existing table or figure. When a chapter was heavily revised, the entire chapter is marked throughout with the Δ symbol. Where one or more sections were deleted, a • is placed between the remaining sections. Chapters, annexes, sections, figures, and tables that are new are indicated with an N.

Note that these indicators are a guide. Rearrangement of sections may not be captured in the markup, but users can view complete revision details in the First and Second Draft Reports located in the archived revision information section at

What’s New in the 2020 NEC®

The evolution of NFPA 70®, National Electrical Code®, has taken place uninterrupted since the code was introduced in 1897. The 2020 edition of the NEC® fits solidly into that tradition, and features important changes related to emergency disconnects, ground-fault circuit interrupter protection, surge protection, and myriad other topics related to electrical safety. NFPA Journal looks at 2020 NEC Highlights.

  • Exterior Emergency Disconnects: Helps to improve electrical safety for emergency responders at one- and two-family dwelling installations.
  • Deenergizing Panel Boards: Revises service disconnect rules to help increase electrical worker safety.
  • Marinas and Boatyards: Updates ground-fault protection and leakage-current measurement device requirements.
  • Power Over Ethernet: Adapts NEC requirements to meet the installation practices of new and evolving technologies.
  • Conducting Load Calculations: Modernizes the tables currently in use for calculations to reflect improvements in energy efficiency.
  • Reorganization of Article 310: Includes new user friendly numbering for important ampacity tables
  • New general requirement: Covering cables installed exposed on ceiling surfaces and sidewalls