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 Answers are based on the 2017 NEC.
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For many years, the mystery of area classification has resided with a select group of experts within the electrical, petrochemical and industrial sectors. Many electricians, electrical engineers, fire inspectors and electrical inspectors have remained outside of this group.

In the 2017 National Electrical code (NEC), there are a few changes in 110.26. The first change is in subsection (A), which is part of a global change for the upper voltage threshold.

Before we proceed, in part 3 of this series, the change in Section 230.70(A)(4) dealing with service disconnects on one- and two-family dwellings was reversed during the late stages of the development process and never made it into the 2017 National Electrical Code (NEC).

More on Codes & Standards

Being Selective

Selective coordination has been a requirement in the National Electrical Code (NEC) for many years but has been limited to a few required applications.

Standard Procedure

Since the beginning of fiber optics, groups such as the Telecommunications Industry Association (TIA) have worked to create standards. Standards are mandatory for technologies to move from R&D to large-scale commercial applications.

Fire Stopping: What Every Contractor Needs to Know

For approximately 40 years, unprotected or improperly protected penetrations have presented a subject of much concern to the fire-protection community. In 1996, an electrical fire occurred at 30 Rockefeller Plaza in New York City.

Box-Fill Calculations, Part XI

314.16 Number of Conductors in Outlet, Device, and Junction Boxes, and Conduit Bodies The National Electrical Code contains provisions that limit the numbers and sizes of conductors that can be installed in boxes and conduit bodies.

Redefining Construction

Construction Specifications Institute (CSI) MasterFormat is the most widely used standard for organizing specifications, catalogs and other documents for commercial and institutional building construction projects in the United States and Canada.

PV Installation: Codes and Standards

The installation of photovoltaic (PV) equipment is governed by a number of industry codes and standards. Electrical contractors need to be aware of the codes and standards to ensure a safe and functional PV installation.

Use the Service Entrance

The text in Section 230.40 covering the number of sets of service-entrance conductors for each service drop or lateral has not changed since it was accepted into the 1984 National Electrical Code (NEC).