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. Send questions to Answers are based on the 2017 NEC.
 Kitchen GFCIs

A friend recently sent me an email with this picture (right) of a manual fire alarm pull station mounted on the side of an electrical panelboard. My friend was inspecting the fire alarm system and was accompanied by the electrician who had installed both the fire alarm and electrical systems.

All of the chapters in the National Electrical Code (NEC) contain tables, but not all of the chapters contain articles. Chapter 9 does not contain any articles; this last chapter only contains tables. The first of two articles in Chapter 1 is Article 100, Definitions.

Reducing differences of potential between conductive equipment or other objects and ground (earth) helps minimize shock hazards in normal circuit operation.

More on Codes & Standards

Properly Installing Nonmetallic Cable-Part II

The number and the content of "Code Question of the Day" submissions concerning the installation of nonmetallic sheathed cable suggests vast differences among, or lack of proper inspection of, electrical installations using Type NM cable as the wiring method.

Branch Circuit, Feeder, and Service Calculations, Motors and Their Circuits and More

CODE CITATIONS: Article 110-Requirements for Electrical Installations; Article 210-Branch Circuits; Article 220-Branch Circuit, Feeder, and Service Calculations; Article 230-Services; Article 250-Grounding; Article 310--Conductors for General Wiring; Article 430-Motors, Motor Circuits, and Controlle

Using a Two-Pole Breaker to Feed Split-Wired Receptacles with Break-off Tabs

It seemed like a simple run-of-the-mill question when first presented. So, let's run it again. QUESTION: "If I split-wire a receptacle by breaking off the tab provided on the receptacle, do I have to use a two-pole breaker to feed this receptacle?" The answer is a qualified yes.

Motor Starter Protection, Copper Conductor Ampacity, and more

CODE CITATIONS: Article 100-Definitions Article 210-Branch Circuits; Article 240-Overcurrent Protection; Article 250-Grounding; Article 310-Conductors for General Wiring; and Article 700-Emergency Systems Type "2" Motor Starter Protection

Conduit Fill and Amapacity Calculations for Low-voltage Systems

Where installing Class 2 or Class 3 remote control, signaling, or power limited circuits in a raceway or where installing power-limited fire alarm circuits in a raceway, is it necessary to figure conduit fill?

Up in the Air Over Mounting Transformers

A proposed location for a 112-kVa 480Y/277 dry transformer suspended above the working space for a switchboard raises several questions.

Installing Lights in Clothes Closets

One of the most confusing aspects of residential wiring is installing lighting fixtures in clothes closets. Therefore, the National Electrical Code (NEC) devotes one of its relatively few diagrams (Figure 410-8) to the subject of where lighting fixtures can be located in clothes closets.