National Electrical Safety Code
The National Electrical Safety Code (NESC) or ANSI Standard C2 is a United States standard of the safe installation, operation, and maintenance of electric power and communication utility systems including power substations, power and communication overhead lines, and power and communication underground lines. It is published by the Institute of Electrical and Electronics Engineers (IEEE). "National Electrical Safety Code" and "NESC" are registered trademarks of the IEEE. The NESC should not be confused with the National Electrical Code (NEC) published by the National Fire Protection Association (NFPA). The NEC is used for residential, commercial, and industrial building wiring.
Access to the NESC
The NESC is written as a voluntary standard. It is typically adopted as law by individual states or other governmental authorities. To determine the legal status of the NESC, the state public service commission, public utility commission, or other governmental authority should be contacted. The majority of the states in the United States adopt the NESC in some form or fashion. The state of California is an exception. The state of California writes their own utility codes titled General Order 95 (GO95) for overhead lines and General Order 128 (GO128) for underground lines. The current edition of the NESC (2017) is available as a spiral bound book containing approximately 345 pages. The NESC codebook can be purchased online from the publisher, from IEEE, or at various third party websites.
Format of the NESC
The NESC is written by various sub committees. The organizations represented, subcommittees, and committee members are listed in the front of the code book. The NESC contains the procedure and time schedule for revising the NESC, which are described in the back of the code book. The NESC has an interpretation committee that issues formal interpretations. The process for obtaining a formal interpretation is outlined in the front of the code book. The NESC is currently published on a 5-year cycle. Urgent safety matters that require a change in between code editions are handled through a Tentative Interim Amendment (TIA) process. Original work on the NESC began in 1913.
The NESC is structured into parts, sections, and rules. There are general sections at the beginning of the book covering the introduction, definitions, references, and grounding. Following the general section are four main parts including: substations rules (Part 1), overhead line rules (Part 2), underground line rules (Part 3), and work rules (Part 4).
Two widely known handbooks are published on the NESC.
- Clapp, Allen J. NESC Handbook: A Discussion of the National Electrical Safety Code. Standards Information Network, IEEE Press. ISBN 978-1-118-14539-5.
- Marne, David J. National Electrical Safety Code (NESC) 2017 Handbook (McGraw-Hill's National Electrical Safety Code Handbook). McGraw-Hill Education. ISBN 978-1259584152.