No Code is Perfect: Corrections to the 2014 NEC

perfect_insights.pngMistakes happen, to err is human, and it is not unusual for the first edition of a book to have typos. The Adventures of Huckleberry Finn holds the record for the most mistakes in a first printing. In general the more errors the first generation of a literary book has, the more valuable it is to a collector.

“Errata” is the plural form of the singular word erratum, and it means errors. An errata is most commonly issued shortly after a first edition is published.

The 2014 National Electrical Code® (NEC) is no exception. The development process takes three years. There are more than 500 people involved in the process. More than 3,700 proposals were submitted, and 1,600 comments considered before printing was started.

There are many changes in the 2014 edition of the NEC. The threshold voltage was revised from 600 to 1,000 Volts in a number of requirements. New articles were added covering low voltage suspended ceilings, modular data centers, fire resistive cable systems, and energy management systems. There are a number of new GFCI and AFCI requirements. The NEC has added a requirement for a rapid shutdown for photovoltaic systems on buildings. With all the changes, a few errors managed to creep into the NEC.

If you purchased the first edition of the National Electrical Code, make sure to download the errata sheet at

Below is a review of the corrections found in the errata sheet.

  1. Shading is used in the 2014 NEC to indicate changes from the 2011 edition of the NEC. In Section 200.7, shading should be removed from the first line of the title. Shading should be added to the words “or Gray” in the second line.

  2. Numbers in table 220.3 were transposed in the Section or (Part Column) of Table 220.3. Relating to the term “Electric vehicle charging system branch-circuit and feeder calculations,” change the section reference to 625.41.

  3. The word “non” makes a big difference to those required to comply with this change. The title of Table 220.44 should be revised to read: “Table 220.44 Demand Factors for Non-Dwelling Receptacle Loads.”

  4. This change was understood in the past code book; however it does provide some clarity to the reader. In Section 400.4, the first sentence should read “Flexible cords and flexible cables shall conform to the description in Table 400.4."

  5. There were two Part II’s in Article 400 so the second one was renamed Part III. The numbering was correct in the 2011 NEC.

  6. Article 422.51(A), titled Vending Machines, please delete the words “identified for portable use.” The result is: All cord and plug connected vending machines manufactured after January 1, 2005, will require GFCI protection as an integral part of the plug. Older machines must be connected to a GFCI outlet.
  7. Article 490.48 is a new section in the 2014 NEC. Please replace Section 490.48 in the 2014 NEC with the following:

    490.48. Substation Design, Documentation, and Required Diagram.

    (A) Design and Documentation. Substations shall be designed by a qualified licensed professional engineer. Where components or the entirety of the substation are listed by a qualified electrical testing laboratory, documentation of internal design features subject to the listing investigation shall not be required. The design shall address but not be limited to the following topics and the documentation of this design shall be made available to the authority having jurisdiction.

    (1) Clearances and exits

    (2) Electrical enclosures<