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.
 Older Type BX cable and EGCs

Article 90 is the introduction to the National Electrical Code (NEC) book, and it includes specifications that are essential to understanding the chapters and informative annexes that follow. For example, Article 90 explains how to recognize mandatory rules versus permissive rules.

During the recent 2017 National Electrical Code (NEC) first revision meetings in Hilton Head, S.C., a number of public inputs were submitted to introduce a new cabling system into Article 725 and Article 760.

The development process of the 2017 National Electrical Code (NEC) has begun. In January, 19 Code-making panels (CMPs) held their “first draft” meetings to address roughly 4,000 public inputs (PIs). The NEC is primarily a reactive code that evolves through demonstrated need.

More on Codes & Standards

Using Two Cables For A Three-Way Switch, Mixing Plastic And Metal, And More

If you have a problem related to the National Electrical Code (NEC), are experiencing difficulty in understanding a Code requirement, or are wondering why or if such a requirement exists, ask Charlie, and he will let the Code decide. Questions can be sent to

If It Ain't Broke ...

In the March 2012 Electrical Contractor, I mentioned the increased number of receptacles in patient bed locations with a minimum of 14 receptacles in a Category 1 critical-care area and 36 receptacles in a Category 1 operating room for the 2014 National Electrical Code (NEC), based on changes in the

Cords For Temporary Wiring

Recently, the question arose about using cords for temporary wiring. It was interesting to watch the reaction and response. It seems there are considerable inconsistencies relative to this subject.

Sizing Conductors, Part XX

Table 310.15(B)(16) (formerly Table 310.16) in the National Electrical Code (NEC) provides allowable ampacities for insulated conductors rated up to and including 2,000 volts (V).

Protecting Conductors, Undercabinet Lighting and More

Protecting conductors For a 1,200-ampere (A), three-phase, 120/208-volt (V) service, can I run three sets of 500 kcmil underground from the transformer pad to the main 1,200A switch, or does it have to be 600 kcmil?

Sizing Conductors, Part XIX

Article 240 in the National Electrical Code (NEC) provides general requirements for overcurrent protection and overcurrent protective devices. When sizing conductors, the rating of the overcurrent device must be considered.

Staying High and Dry

How do you design, protect and locate a dry-type transformer of 600 volts (V) or less so that the installation will comply with the National Electrical Code (NEC)?