National Electrical Installation Standards

Standards as High as Your Own

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Wednesday, October 31, 2018

Question:

Hi Charles, at what voltage do you start to need arc flash protection.

Brad Lester

A

Answer:

Hey Brad thanks for your question. The need for protection from an arc flash event is not determined based only on voltage but is based on incident energy and the likelihood of an arc flash event occurring. The arc-flash hazard warning sign required by 110.16 does not have a lower voltage limit but has examples of types of equipment it applies to.

NFPA 70E, the Standard for Electrical Safety in the Workplace, requires employers to perform arc flash risk assessments as stated in 130.5 of that standard and to implement a hierarchy of risk control methods as stated in 110.1(H)(3). The definition of Electrical Hazard in Article 100 of NFPA 70E has an informational note explaining that class 2 power supplies, listed low voltage lighting systems and similar sources are not considered electrical hazards.

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IMPORTANT NOTICE: All answers are based on the latest edition of the National Electrical Code®, unless the question requests a response based on a specific edition. This correspondence is not a formal interpretation of the NEC®. Any responses expressed to the questions are opinions and do not necessarily represent the official position of NECA, NFPA, or any technical committee. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services.

ABOUT CHARLIE: Charles M. Trout, better known as Charlie, was a nationally known NEC® expert and author. He served on several NEC® technical committees and is past chairman of CMP-12. In 2006 Charlie was awarded the prestigious Coggeshall Award for outstanding contributions to the electrical contracting industry, codes and standards development, and technical training. Charlie was also a member of NECA’s Academy of Electrical Contracting. Charlie’s experienced team of industry experts keep the CQD dialogue and discussions active and informative in the spirit of the man himself, as he wanted.

NECA STANDARDS: NECA publishes the National Electrical Installation Standards™ (NEIS™), a series of ANSI-approved performance and quality standards for electrical construction. Visit NECA-NEIS.org for more information. NEISÔ can be purchased in three formats: as paper books, on CD, or as electronic downloads.

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