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. Send questions to codefaqs@gmail.com. Answers are based on the 2020...
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...
The standards development system for the National Electrical Code is a public, consensus-driven process. The NEC receives thousands of public inputs and comments every cycle. But how can a book be consistent if it has...
The National Electrical Code is designed for the practical safeguarding of people and property from hazards arising from the use of electricity. The two major hazards are shock and fire, but the third, arc flash, is starting...
Last month’s article covered the technical requirements of power over ethernet (PoE), limited-power (LP) cable, regular Class 2 and 3 cables and the temperature limitations of Class 2 and Class 3 cables and installations. But...
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. Send questions to codefaqs@gmail.com. Answers are based on the 2017...
The National Electrical Code is a complete collection of rules for electrical installation requirements suitable for adoption into law. It contains no guidelines or recommendations. It does not contain “best practices,” nor...
Part 5 of this series focuses on revisions in Chapter 3 of the 2020 NEC, “Wiring Methods and Materials,” which covers the general requirements for wiring and the requirements specific to each wiring method, such as electrical...
In the last year or two, I have written a few articles about NFPA 3, Recommended Practice for Commissioning of Fire Protection and Life Safety Systems, and NFPA 4, Standard for Integrated Fire Protection and Life Safety...
Article 110 in the National Electrical Code (NEC) contains requirements that cover a wide variety of topics. As the scope in 110.1 states, the article provides general requirements for the examination and approval...
There are many types of transformers with just as many different uses. Transformers can be installed within electrical equipment, as separate individual transformers, as polyphase banks of two or more single-phase...
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...
Recently, the question arose about using cords for temporary wiring. It was interesting to watch the reaction and response. It seems there are considerable inconsistencies relative to this subject. Perhaps a practical...
How do you design, protect and locate a dry-type transformer of 600 volts (V) or less so that the installation will comply with the National Electrical Code (NEC)?Providing overcurrent protection: Table 450.3(B) is used to...
The 2012 NFPA 70E, The Standard for Electrical Safety in the Workplace, is nearing completion. This will be the ninth edition since it was first published in 1979.During the last revision cycle, the NFPA 70E committee...
Many electrical designs incorporate parallel arrangements. The National Electrical Code (NEC) requires parallel conductors when supplying large switchboards and other large electrical equipment because large single conductors...
