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...
New Section 680.4 in Article 680 in the 2020 National Electrical Code enables the authority having jurisdiction (AHJ) to require periodic inspection and testing of swimming pools, fountains and similar installations such as...
Some of the most challenging electrical installations involve healthcare. From major hospitals to clinics in pharmacies, anyone who is not intimately familiar with the intricacies of medical headwalls, major electrical...
July’s article provided a preliminary discussion on cathodic action and dissimilar metal reaction with deterioration of various metals, such as steel water and gas lines. Many of the old metal underground natural gas lines...
Cathodic action and dissimilar metal interaction are phenomena with a long history of recognition in the laws of physics as well as within the National Electrical Code. I first ran across this issue back in the 1970s and ‘80s...
Periodically, a change in the National Electrical Code occurs that is long overdue, such as 2020‘s new Section 300.25. This change may have long-term consequences for electrical contractors, especially if the designer...
