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. 

Grounding methods and requirements for systems operating at more than 1,000 volts (V), such as 5- and 15-kilovolt (kV) systems, differ slightly from those for systems of 1,000V or less. Systems in these voltage ranges are commonly referred to as medium-voltage systems.

GFCI in locker rooms

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. Send questions to Answers are based on the 2017 NEC.
 GFCI in locker rooms

Those of us who use the National Electrical Code (NEC) on a regular basis and are familiar with the words as well as the intent of the text can often overlook the most obvious interpretations by the rest of the electrical industry.

National Electrical Code (NEC) Article 110 covers general requirements for the examination and approval, installation and use, access to and spaces about electrical conductors and equipment; enclosures intended for personnel entry; and tunnel installations.

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.

Image shows proper fire stopping
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).