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

Branch-Circuit, Feeder and Service Calculations, Part III

220.14 Other Loads—All Occupancies Article 220 of the National Electrical Code (NEC) contains requirements for calculating branch-circuit, feeder and service loads. Knowing how to perform load calculations is an essential part of being an electrician.

A Concept Change

Hidden within the rewrite of Articles 511 and 514—which cover repair garages for motor vehicles and motor fuel dispensing stations, respectively, in the 2005 National Electrical Code (NEC)—is a major change in the concept of hazardous (classified) locations.

Overcurrent Protection, Disconnecting Means and Mo

Disconnecting means Q: Disconnecting means for circuits supplied by a generator are required where the circuits enter a building or structure. Are these disconnects from an outdoor generator required to meet the rules in Article 225? Is there a maximum number of disconnects permitted?

Entries into Raintight Enclosures, Derating NM-B C

Cables in metal framing member Q: Sections 320.17 and 330.17 require that Types AC and MC cables be installed to comply with 300.4.

Branch-Circuit, Feeder and Service Calculations, Part II

An essential part in the life of an electrician is performing load calculations. Determining what size conductors and overcurrent protective devices to install is something most electricians do on a daily basis.

Household Applications and the Code

Providing branch-circuit overcurrent protection and subdividing electrical resistance-heating elements in appliances and fixed electric space heating equipment has been a long- standing requirement in the National Electrical Code (NEC).

Assembly Occupancies, Overcurrent Protection and More

Electric service for grounding-electrode conductors Q: The electric utility in our area requires the installation of a ground rod and grounding-electrode conductor in the meter socket. Is it acceptable to ground the grounded-circuit conductor (neutral) in the service-disconnect enclosure?