Evolving the National Electrical Safety Code (NESC)

The NESC (National Electrical Safety Code) informs utility work and contributes to the safety of utility workers and the general public in a variety of ways.

By Michael Hyland, IEEE December 31, 2014

Since its introduction in 1914, the National Electrical Safety Code (NESC) has been a rich source of safety practices associated with electric supply and communication systems such as telephone, cable, and railroad signal systems and their associated equipment. Today, there is a globally open, never-ending effort to keep the code effective and relevant as new technologies are introduced and new challenges are confronted in the field of implementation.

The NESC’s role and scope

The code applies from the point of generation of power or communications signals to the customer “service point,” which is where power or communications are transferred to a premises wiring system. Electric supply stations (both generating facilities and substations), high-voltage transmission towers, joint-use poles for local distribution of communication and power services, underground systems, and buried areas in easements and rights-of-way are among the sweeping range of applications that are addressed in the code.

Today, nearly all of the U.S. states use the NESC in whole or part by way of legislative, regulatory, or voluntary action. As an example, California uses its own state safety code but reviews its requirements when each new edition of the NESC is released (every 5 years). Some U.S. states adopt only the NESC’s construction and maintenance rules while others, though they might not directly adopt a safety code for utilities, refer to the current edition of the NESC when issues arise related to the code’s scope. About 100 countries globally leverage the code in some way—though, in some countries, the NESC is modified to account for local climate anomalies. For example, in November 2015, IEEE and the Pakistan Engineering Council (PEC) announced completion of the Pakistan Electric and Telecommunication Safety Code (PETSAC-2014), based in part on the NESC. PETSAC-2014 provides rules for safe practices in design, installation, operation, and maintenance of electric supply and telecommunication systems. 

Individual utilities often leverage the NESC in their own standards and safety programs, such as safety manuals, “tailboard discussions,” all-hands safety meetings, spot checks to ensure regulations are being followed, apprentice programs, etc.

And while the developers of the code are clear that the code is not a design manual, it is also true that the NESC is leveraged as a source of design criteria for distribution facilities for the power and communication industries globally. In this way, the code impacts consulting and specifying engineers in their work on designs for utilities, private companies, and municipalities.

A structured, 5-year process of revision

The NESC is methodically revised via an open and inclusive 5-year process overseen by the IEEE Standards Association (IEEE-SA). The world’s largest professional organization dedicated to advancing technology for humanity, IEEE has been the secretariat of the code since 1972, and the IEEE-SA is the organization’s standards and collaborative solutions arm. Any interested party is given the opportunity to weigh in on the code’s evolution, and a new edition reflecting that input is published every 5 years. Key revisions and/or clarifications in areas such as the NESC’s application in relation to NFPA 70: National Electrical Code, techniques for effective grounding, protection of electrical supply stations, underground inspection rules and requirements, apparel arc ratings, and minimum-approach distances were among the changes introduced in the most recent, 2012 edition of the code.

The changes that are under consideration in the current revision cycle of the NESC include:

  • Definitions for communication equipment, electric supply equipment, and structure conflict
  • Clearance rules associated with communication space above supply space
  • Bringing into harmony the NESC’s work rules with OSHA 29 CFR §1910.269 and §1926 Subpart V final rulings.

The next steps in the march toward finalization of the 2017 edition of the code are the submission of a proposed revision by the NESC Accredited Standards Committee C2 to the NESC Main Committee by Jan. 15, 2016, for letter ballot, and also to ANSI for concurrent public review. Once the ballot is confirmed and all public comments are addressed, the next edition is scheduled for publication on Aug. 1, 2016.


Since its introduction in August 1914, the NESC has served as an invaluable, widely relied-upon tool for utility field technicians, contractors, and customers throughout the United States and an increasing number of other countries around the world. The code is respected for working within its scope to help protect the safety of both utility workers and the general public during installation, operation, and maintenance of electric supply and communication lines and their associated equipment.

Please visit https://standards.ieee.org/about/nesc/ to learn more about the code’s history and how you can contribute to the ongoing, globally open effort to ensure it remains a vital and relevant resource protecting utility worker and public safety.

Michael Hyland is NESC chair and senior vice president of engineering services at the American Public Power Association (APPA).