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. 

In the electrical industry, a new method of protecting workers from arc energy is gaining popularity: prevention through design. Simply speaking, the design and installation of equipment or systems incorporates inherent safety features that protect workers from serious arc-flash injuries or death.

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.
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National Electrical Code (NEC) Article 110, “Requirements for Electrical Installations,” applies generally to all electrical installations, like all of the articles located in the first four chapters.

Safety for solar photovoltaic (PV) systems has come a long way since the first installation requirements were inserted as Article 690 into the 1984 National Electrical Code (NEC).

More on Codes & Standards

Overcurrent Protection, Access to Working Space, Snap Switches, and More

CODE CITATIONS Article 110—Requirements for Electrical Installations Article 240—Overcurrent Protection Article 250—Grounding Article 380—Switches Article 384—Switchboards and Panelboards Article 450—Transformers and Transformer Vaults

Low-voltage Lighting - Listed Systems or Individual Field-assembled Components?

Does the National Electrical Code (NEC) require all lighting installations operating at 30 volts or less to be Listed systems? Can individual low-voltage lighting components, such as a power supply, fixtures, and conductors be assembled in the field without being part of a Listed system?

How Effective Is Overcurrent Protection in the Tap Rules?

The location in the circuit of the overcurrent protection permitted in the tap rules of Sec. 240-21 raises some questions regarding the effectiveness of the overcurrent protection.

Classification of a Hazardous Location

The hazardous locations covered by Chapter 5 of the National Electrical Code (NEC) are classified in accordance with the properties of flammable liquids, gases, vapors, combustible dust, or ignitable fibers or flyings that may be present in the area where electrical equipment may be installed.

Why Does the NEC Prohibit Overcurrent Device Installation in Clothes Closets?

February’s “Code Question of the Month” column addressed overcurrent device installation in clothes closets. The questions were: (1) May service equipment (overcurrent devices in a panelboard) be installed in a walk-in clothes closet?

Motor Control Circuits: To Ground or Not to Ground?

Should motor control circuits be grounded? Here are some guidelines: If a motor control circuit is tapped from the motor circuit and does not leave the controller enclosure (the push buttons are in the cover), then it need not be grounded. [90-7 ¶ 2, 300-1(b), 450-1 Exc.No.2]