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.
 Grounding electrode
conductor termination

The first National Electrical Code (NEC) was developed in 1897. The National Fire Protection Association (NFPA) became the developer and publisher of the National Electrical Code (NEC) in 1911, and the NFPA continues to develop and publish the Code today.

New text in section 424.66(A) of the 2014 National Electrical Code (NEC) covers working space for electrical enclosures of resistance heating-element-type duct heaters mounted on air-duct systems in limited-access areas.

For many years, The National Electrical Code (NEC) has provided rules for equipment disconnects. NEC requirements are very specific for motors and motor-driven machinery, but they differ from lockout/tagout rules in NFPA 70E, Standard for Electrical Safety in the Workplace. The reason is simple.

More on Codes & Standards

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]

Taming the Fire-Breathing Dragon

If you thought industry standards had pretty much solved the problem of electrical injuries and fatalities in the workplace, then you should know that is not the case.