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. 

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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 Answers are based on the 2014 NEC.
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The model building code treats campus dormitories as residential occupancies. However, a dorm does not function the same as a commercial apartment building. In some cases, the architect has created a physical design to accommodate as many students as possible.

Are multiwire branch circuits becoming antiquated for most new installations, or are they still being used in most circuit applications?

The National Electrical Code (NEC) is divided into an introduction and nine chapters with 10 informational annexes. As specified in 90.5(D), the informative annexes are not part of the NEC’s enforceable requirements but are included for informational purposes only.

Electrical Contractor

More on Codes & Standards

Equipotential Plane and Voltage Gradients in Agricultural Settings and Raised Floors in IT Rooms

This month’s column addresses two rather different, recurring subjects on Electrical Contractor magazine’s “Online Code Question of the Day.” QUESTION: When building a barn for horses, I was required to establish an equipotential ground plane at the entrance, from the concrete floor of the barn to t

Article 370-Boxes, Conduit Bodies and Fittings

An enclosure that contains a device(s), or supports a fixture(s) or other equipment can be supported by the entering raceways when all of the following conditions are met: 1) the enclosure does not exceed 100 cubic inches in size; 2) the enclosure has threaded entries or hubs identified for the purp

Branch Circuits, Feeders, Service Calculations, Motors, Motor Circuits, Controllers, and More

CODE CITATIONS Article 210—Branch Circuits; Article 220—Branch-Circuits, Feeder, and Service Calculations; Article 225—Outside Branch Circuits and Feeders;

Outside Branch Circuits or Feeders - Is a Separate Disconnect Required?

In the 1996 National Electrical Code (NEC), Section 225-8, the requirements for installing a separate disconnecting means for a branch circuit or feeder to a separate building or structure on the same property were fairly simple.

The Assured Equipment Grounding Conductor Program

In keeping with the stated purpose of the National Electrical Code (NEC), the “practical safeguarding of persons and property…” protecting workers from electrical shock while using temporary power is of great concern for all electrical contractors.

Noteworthy Code Changes Concern Branch Circuits

Several changes in the 1999 National Electrical Code (NEC) in Article 210, Branch Circuits, are worthy of comment.

Article 370 - Boxes, Conduit Bodies, and Fittings

370-23(d)(2) Enclosures Fastened to Support Wires