Electrical supply and communications systems in the United States were isolated structures by the early 1900s, serving only a city or region. Each system was built differently, with different construction materials, and no guidelines were set for, say, the height of overhead power lines or anything else. Nor were there common safety procedures for operators to follow.
With no standards, electrical workers as well as the public faced a host of safety issues. As you might expect, power lines did often hang too low, but electrical substations were also poorly built and work practices were inconsistent. Wiring methods were just plain unsafe. Serious injuries and even deaths from fires were common, caused by blown fuses, short circuits, improper grounding, and exposed wires. Such problems were only compounded as systems grew and smaller systems were linked together to take advantage of economies of scale.
The resulting hazards led to a congressional mandate for the National Bureau of Standards to develop what became the National Electrical Safety Code (NESC). The bureau brought together representatives from the major players—electric utilities and phone companies, railroads, labor unions, and factory owners—to identify the common problems and develop solutions.
The result was a practical, unified, national code—a set of rules or standards—for building and installing electrical systems and wiring. The first edition was issued in May 1914 and covered only work rules. Updates covering construction and wiring issues followed. As each state adopted or used some version of it, the code brought consistency and safety to the design, construction, operation, maintenance, and use of electrical supply and communications installations throughout the United States.
Now published by the IEEE Standards Association, the code is revised every five years. Over the years, the NESC became the go-to guide for any organization concerned with electrical safety: utilities, contractors, manufacturers, phone companies, cable TV providers, railroads, and others. More than 100 countries also use the U.S. code.
“NESC has continually evolved as technology has evolved and quite literally helped save lives,” says Mike Hyland, chair of the NESC Committee and senior vice president of engineering at the American Public Power Association, in Washington, D.C. “To remain realistic, practical, and useful in the face of new developments and technologies and challenges in the industry, NESC is constantly being refined. Today it is a relevant, essential resource that protects the public, electrical professionals, equipment, and property.”
IEEE STEPS IN
By the late 1960s, a significant overhaul of the code was needed to incorporate advances in materials, design, uses, and construction and operating techniques. The National Bureau of Standards began this rewrite in 1968, but due to changes to its operations in 1972, it asked to be relieved of its daily administrative tasks, known as secretariat duties. In its place, IEEE was selected to serve as secretariat and now provides a home for the NESC Committee and supports its activities with a full range of administrative, logistical, publishing, and other services. IEEE also serves as liaison between the NESC and other standards committees to coordinate activities where their operations intersect.
On 1 September, proposed revisions to the most recent code, the NESC 2012 edition, to be incorporated into the 2017 version will be published and distributed by IEEE-SA. An eight-month period for comments will follow, allowing interested parties to review, affirm, or suggest changes. The call for comments closes on 1 May 2015.
For more information, visit the NESC.