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. 

Article 450 in the National Electrical Code (NEC) covers requirements for transformers. The scope of Article 450, located in 450.1, states that it covers the installation of all transformers, but there are eight exceptions.

NFPA 70, the National Electrical Code (NEC), is an installation code, while NFPA 70E is the Standard for Electrical Safety in the Workplace. There is an unofficial line of demarcation between the two documents.

An electrical contractor recently requested information about the required emergency disconnects for a motor-fuel-dispensing facility.

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.
 Phase converters and fire-pump service

More on Codes & Standards

That's Secondary

In the November 2011 issue, I wrote about the rewrite of Section 250.30(A)(1) through (A)(8) in the 2011 National Electrical Code (NEC). Last month, I discussed the grounding and bonding procedures using the grounded conductor at the service equipment and outside utility transformer.

Sizing Conductors, Part IX

When sizing conductors, the number of current-carrying conductors installed in a raceway or cable must be considered. No conductor shall be used in such a manner that its operating temperature exceeds that which is designated for the type of insulated conductor involved [310.15(A)(3)].

Boat Dock Conduit, Pool Deck Heating 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

LEDs Are Everywhere

In the past few editions of the National Electrical Code (NEC), light-emitting diode (LED) illumination systems have been inserted into almost every article where lighting is mentioned.

See You on the Supply Side

At a recent workshop that I was teaching, a question was asked about how the grounded conductor was to be installed and used when routed from the outside utility transformer to service equipment located inside the facility.

Sizing Conductors, Part VIII

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

Going Green Through Code

It was only a matter of time before green became codified. This spring, the International Code Council (ICC) officially will roll out its International Green Construction Code (IgCC).