The NEC is available as a bound book containing approximately 1000 pages. It has been available in electronic form since the 1993 edition. Although the code is updated every three years, some jurisdictions do not immediately adopt the new edition.
The NEC is also available as a restricted, digitized coding model that can be read online but not saved, copied and pasted, or printed, free of charge on certain computing platforms that support the restricted viewer software.
In the United States, statutory law cannot be copyrighted and is freely accessible and copyable by anyone. When a standards organization develops a new coding model and it is not yet accepted by any jurisdiction as law, it is still the private property of the standards organization and the reader may be restricted from downloading or printing the text for offline viewing. For that privilege, the coding model must still be purchased as either printed media or a CD-ROM. Once the coding model has been accepted as law, it loses copyright protection and may be freely obtained at no cost.
Archive.org and many state or local government sites allow download of the NEC without the registration that the NFPA requires.
External links to both the restricted NEC online access and free public access sites are referenced at the end of this article.
The rural electrification drive during the New Deal led to a wide expansion in the number of jobs in the electric power industry. Many power linemen during that period traveled around the country following jobs as they became available in tower construction, substation construction, and wire stringing. They often lived in temporary camps set up near the project they were working on, or in boarding houses if the work was in a town or city and relocating every few weeks to months. The occupation was lucrative at the time, but the hazards and the extensive travel limited the appeal.
A brief drive to electrify some railroads on the East Coast of the U.S. led to the development of specialization of linemen who installed and maintained catenary overhead lines. Growth in this branch of line work declined after most railroads favored diesel over electric engines for replacement to steam engines.
The occupation evolved during the 1940s and 1950s with expansion of residential electrification. This led to an increase in the number of linemen needed to maintain power distribution circuits and provide emergency repairs. Maintenance linemen mostly stayed in one place, although sometimes linemen were called to travel to assist repairs. Also during the 1950s, some electric lines began to be installed in underground tunnels, expanding the scope of the work.
The first interior power wiring systems used conductors that were bare or covered with cloth, which were secured by staples to the framing of the building or on running boards. Where conductors went through walls, they were protected with cloth tape. Splices were done similarly to telegraph connections, and soldered for security. Underground conductors were insulated with wrappings of cloth tape soaked in pitch, and laid in wooden troughs which were then buried. Such wiring systems were unsatisfactory because of the danger of electrocution and fire, plus the high labour cost for such installations.
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