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. 

Slash-rated breakers on 480V ungrounded delta?

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.
 Slash-rated breakers on 480V ungrounded delta?

Article 110 in the National Electrical Code (NEC) contains general requirements for electrical installations. Some of the topics covered include examination and approval, installation and use, and access to and spaces about electrical conductors and equipment.

A caller recently asked if all 125-volt (V), 15- and 20-ampere (A) receptacles in a commercial kitchen were required to be ground-fault circuit interrupter (GFCI) protected, even where part of a listed assembly.

The decision to install and operate an ungrounded system is typically a combined effort that includes a design or engineering team, the owner, the operators and sometimes the authority having jurisdiction.

More on Codes & Standards

Grounding Electrodes, SE Cables and More

Fire pump disconnecting means Q: Is the disconnect for an electric motor driving a fire pump required to be within sight of the motor or is it permitted to be out of sight if capable of being locked in the off position? Can the disconnect and overcurrent protection be located in a panelboard?

Pull- and Junction-Box Calculations, Part IV

314.28 Pull and Junction Boxes The National Electrical Code covers outlet, device, pull and junction boxes; conduit bodies; fittings; and handhole enclosures in Article 314.

Emergency Protection ... Stat!

Providing mechanical protection for branch circuits supplying critical loads in a hospital is extremely important. Any potential damage to these circuits could cost lives.

Panelboards in Stairways, Color Coding and More

Control-circuit transformers Q: Do the requirements of Article 450—Transformers and Transformer Vaults or Article 725—Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits apply to a control-circuit transformers in a 480-volt combination motor starter?

Pull- and Junction-Box Calculations, Part III

314.28 Pull and Junction Boxes Requirements pertaining to the installation and use of all boxes and conduit bodies used as outlet, device, junction or pull boxes are in Article 314 of the National Electrical Code.

When to Supplement

A new definition covering supplementary overcurrent-protective devices has been added to Article 100 in the 2005 National Electrical Code (NEC) to indicate that limited protection may be provided for specific applications or utilization equipment.

Connecting Kitchen Hood Fans, Indoor Receptacles, and More

Laundry GFCI receptacles Q: Are all 15- and 20-ampere, 125V receptacles installed within six feet of a laundry or utility sink in a dwelling occupancy required to be protected by a ground fault circuit interrupter even where the receptacle is not readily accessible such as behind a clothes washer o