Codes & Standards

 

Essential to the work of the electrical contractor is knowledge of the National Electrical Code, the National Electrical Installation Standards and additional standards and codes administered by the National Fire Protection Association, the Occupational Safety and Health Administration and others. Here is a list of all our articles on codes and standards listed chronologically by issue date. 

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Questions can be sent to codefaqs@gmail.com. Answers are based on the 2014 NEC.
 Previous use of gray conductors


Article 310 in the National Electrical Code (NEC) covers general requirements for conductors and their type designations, insulations, markings, mechanical strengths, ampacity ratings and uses.

A recent change in the 2014 National Electrical Code (NEC) creates a new method for determining the size of service and feeder conductors for 120/240-volt (V), single-phase services for one-family, individual units of two-family dwellings, and individual units for multifamily dwellings.

The 2014 National Electrical Code (NEC) has new requirements for field-applied hazard warning markings, signs and labels. Throughout the NEC, rules that required signs, labels and other markings also required a specific signal word be included in the sign, label or marking.

More on Codes & Standards

 
Figure 1: 10-foot feeder tap
Applied Tap Rules

Someone recently asked me to explain the differences between the 10-foot tap rule and the 25-foot tap rule as they apply to feeders. An additional question was raised about connecting multiple taps to the same feeder using both the 10- and 25-foot tap rules.

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GFCI protection at in-ground swimming pool

The Best Of Code Question Of The Day, Part II

Charlie Trout, author of Code FAQs and Code Question of the Day, has retired. 
For the rest of 2013, enjoy these snippets from his daily responses.
 Calculating conductors and breakers


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Sizing Conductors, Part XXX

transformer secondary conductor rules are similar to tap conductor rules. Article 240.21 of the National Electrical Code (NEC) covers the location and sizing requirements of overcurrent protection for tap conductors and transformer secondary conductors.

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Directly To The Point

The 2014 National Electrical Code (NEC) process received more proposals—including a total of 45 generated by the NEC Correlating Committee Task Group on direct current (DC)—and comments to insert DC into the Code than any other NEC cycle in history.

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Editors' Pick
2014 NEC Outlook, Part III

This article is a continuation of a concise and complete review of some of the more significant changes that have been incorporated into the 2014 edition of the National Electrical Code (NEC). This segment takes a look at some significant revisions in chapters 4 through 6.

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Power Down To Earth

Many buildings and structures are supplied by power from a source other than a utility service. If the supply—such as a transformer or generator—is customer-owned, it is not a service and, therefore, is either a feeder or branch circuit.

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Service panel makeup

The Best Of Code Question Of The Day, Part I

Charlie Trout, author of Code FAQs and Code Question of the Day, has retired. 
For the rest of 2013, enjoy these snippets from his daily responses.
 Follow specs or nameplate?


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