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.
 Grounding electrode
conductor termination


The first National Electrical Code (NEC) was developed in 1897. The National Fire Protection Association (NFPA) became the developer and publisher of the National Electrical Code (NEC) in 1911, and the NFPA continues to develop and publish the Code today.

New text in section 424.66(A) of the 2014 National Electrical Code (NEC) covers working space for electrical enclosures of resistance heating-element-type duct heaters mounted on air-duct systems in limited-access areas.

For many years, The National Electrical Code (NEC) has provided rules for equipment disconnects. NEC requirements are very specific for motors and motor-driven machinery, but they differ from lockout/tagout rules in NFPA 70E, Standard for Electrical Safety in the Workplace. The reason is simple.

More on Codes & Standards

 
AFCIs Settle Into Code

Installation requirements for arc-fault circuit interrupters (AFCI) in 210.12 of National Electrical Code (NEC) have been modified considerably in the past three NEC cycles and have changed dramatically in the 2014 NEC.

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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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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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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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