In last month’s column, I explained the proper use of the term “panelboards,” which are the interior busing and breaker terminations covered by parts I and III of Article 408. That article was more involved in covering the...
Many people refer to the enclosure and the interior panelboard as a “panelboard.” Panelboards do not include the enclosure or cabinet, so this is a misappropriation of a more complex application and piece of equipment...
In the 2005 National Electrical Code, Article 430 was rearranged to make requirements on adjustable-speed motor drives more detailed and easier to locate in the new Part X. These requirements were previously scattered...
I have recently been doing plan reviews of electrical equipment and installations operating at over 1,000V and find myself having to dust off my knowledge base for these requirements. As an electrician, an electrical...
In the past few Code cycles, more emphasis has been provided on marking electrical branch circuits and feeders to indicate where the source of energy originates, the amount of fault current available at the service and how...
Last month, I provided a basic outline and history of Critical Operations Power Systems (COPS) located in Article 708 of the National Electrical Code. This article features details about Article 708 and the differences...
When a hurricane is approaching, your attention immediately goes to the Weather Channel, cellphones or computers for updates, if you’re in an affected area. When traveling, we can find out the approximate temperature...
When an area containing flammable or combustible material is properly classified and the electrical installation is appropriately designed and installed, these areas are no more dangerous than any other location. The key to...
A chief electrical inspector friend wanted to know about the construction of an oxygen-generating facility in the Raleigh/Durham, N.C. area. His question was whether the construction should be based on the hazardous...
One of the protection techniques recognized in 500.7(K) in Article 500, covering general protection installations in a hazardous location, is the use of a combustible-gas-detection system. In the years since the 2002 National...
In the past three editions of the National Electrical Code (2014, 2017 and 2020), we have seen major changes in the requirements for electrical systems in healthcare facilities. In the 2014 NEC, the reference to requirements...
Section 90.2(B)(5) states that the National Electrical Code does not apply to installations that are under the exclusive control of the electric utility company. Has anyone ever questioned the validity of this requirement...
Certain phrases are used so commonly in the electrical industry that an explanation seems to be almost unnecessary. However, the definition might not specifically be found within the National Electrical Code. One phrase that...
I was recently asked an interesting question involving parallel copper, aluminum and copper-clad aluminum conductors installed in parallel. The question was about 310.10(G), and whether cables installed in parallel must be...
Chapter 7 of the National Electrical Code includes many articles, such as Emergency Systems (Article 700); Legally Required Standby Systems (Article 701); Optional Standby Systems (Article 701); Class 1, 2, and 3 Remote...
Requirements for the number and location of receptacles for dwelling unit kitchen countertops, islands and peninsulas changes with every National Electrical Code cycle. Many of these changes stem from architects’ and custom...
Following up on my November 2020 article, here is further information on the ramifications of the change to the long-standing six disconnect rule in Section 230.71 of the National Electrical Code . Remember that this rule was...
More documentation is being required in the National Electrical Code and NFPA 70E, the Standard for Electrical Safety in the Workplace. The words “documented” or “documentation” appear in the 2017 NEC approximately 104 times...
Arc energy reduction is critical for working on high-energy electrical equipment. However, many electrical designers, contractors and inspectors don’t understand the issues surrounding energy reduction. Arc energy reduction...
Sometime between the 1925 and 1933 National Electrical Codes , the maximum number of service disconnects changed from one or two disconnects to a maximum of six. I cannot verify the exact edition where the change occurred. I...
