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 2014 NEC.
 Pull boxes for communications cable

Article 110 in the National Electrical Code (NEC) covers general requirements for the examination and approval, installation and use, and access to spaces about electrical conductors and equipment; enclosures intended for personnel entry; and tunnel installations (110.1).

The DC Task Group of the NEC Correlating Committee is proposing three new articles for the 2017 edition of the National Electrical Code (NEC). The first is Article 706, covering energy-storage systems (ESS). The second is Article 710, covering microgrids.


The National Electrical Code (NEC) requires all boxes and enclosures—including transfer switches, generators and power panels that are part of an emergency system—to be marked so they are readily identifiable as a component of the emergency system.

Electrical Contractor Magazine

More on Codes & Standards

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

Grounding Electrode Connections, Bonding around Swimming Pools, Sizing the Neutral Conductor, and More

CODE CITATIONS Article 250—Grounding; Article 310—Conductors for General Wiring; Article 410—Lighting Fixtures, Lampholders, Lamps, and Receptacles; Article 501—Class I Locations; and Article 680—Swimming Pools, Fountains, and Similar Installations Grounding electrode connections

Improperly Sized Conduit Bodies Can Lead to Conductor Damage

The requirements for the construction and installation of conduit bodies are mixed with those for boxes and fittings in Article 370 of the National Electrical Code (NEC).

Enforcing and Administering the NEC

The National Electrical Code (NEC) enjoys the reputation of being the most widely accepted standard in the world. The document is intended to provide for the practical safeguarding of persons and property from hazards associated with electrical installations.

Surpassing Standard Overload Protection

"What is the full load current of that motor over there?” “Which current rating do you want? Each motor has three current ratings: nameplate, NEC Table, and locked rotor.”

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

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;