Eight things you may not know about the National Electrical Code

Note: This article is summarized from a September 16, 2016, Solar Power World article with permission from Solar Power World.

SOLAR_MARVIN_HAMONIn preparation for the 2017 National Electrical Code (NEC) Solar Power World shared key points from a presentation at Solar Power International by Marvin R. Hamon, Hamon Engineering, about understanding the NEC and how industry standards are created. Here are some of the highlights:

  1. NEC development is headed and published by the National Fire Protection Association (NFPA). It has been adopted in all 50 states and serves as the benchmark for safe electrical design, installation and inspection to protect people and property from electrical hazards. The first edition was published in 1897.
  2. Though headed by the NFPA, it’s mostly volunteer based and any individual can contribute. Some people form or join working groups to contribute to the NEC collectively.
  3. Anyone or any group can recommend proposals or changes to the code in between editions. Sometimes these proposals are made into tentative amendments to the code. Suggesting a proposal is as easy as filling out a form, but you must include a substantiation of why you want to make the change so that your intention is clear.
  4. The same code paragraph can mean different things to different people. The code development process also results in poor wording, even with proofreading errors. To help make things a little clearer there’s an NEC style manual, which serves as a guide on how words and style are used in the NEC.
  5. External resources are available to help interpret NEC, including online forums like Mike Holt’s code forum and RE-wrenches’ email list.
  6. Article 690 on solar code has numerous changes each year since solar is such a fast-paced industry. Meanwhile, Article 450 about transformers might only have some minor changes within the span of 20 or 30 years.
  7. The NEC is typically adopted by states and municipalities as they aim to standardize enforcement of safe electrical practices. In some cases, codes may be amended, altered or rejected in lieu of regional regulations voted on by local governments.
  8. The NEC doesn’t define standards; Underwriters Laboratories (UL) does. For example, the NEC might say that there must be arc-fault detection installed, but not how the detection device must operate. UL then determines operational and safety requirements for the device and creates a specification.

For more insight, see the full article at Solar Power World.