My last article provided a history and background on Article 400, dealing with flexible cords and cables. This month, I delve further into whether flexible cords and cables could or should be installed in concealed locations.
Concealment of flexible cords and cables that are installed as an integral part of appliances—or when used for connecting other electrical equipment—is an ongoing issue for the electrical industry. The history of the National Electrical Code (NEC) provides some insight.
The concept of modular data centers (MDCs) originated about six or seven years ago as a portable method of delivering information technology data center capacity without the high cost and long construction time.
NFPA 70, the National Electrical Code (NEC), is an installation code, while NFPA 70E is the Standard for Electrical Safety in the Workplace. There is an unofficial line of demarcation between the two documents.
The 2011 National Electrical Code (NEC) introduced changes that required ground-fault circuit interrupter (GFCI) protection to be readily accessible, and the 2014 NEC presents further changes regarding ready access of these devices. Were these changes necessary?
Available fault current, short-circuit current rating, arc energy, arc flash hazards, and incident energy are closely related in both the National Electrical Code (NEC) and NFPA 70E, Standard for Electrical Safety in the Workplace.
For many years, Article 250, which covers grounding and bonding in the National Electrical Code (NEC), only contained two tables. Table 250.122 was used for sizing the equipment grounding conductors, based on the size of the overcurrent protective device in the circuit.
This article returns to the topic of my December 2013 column, which dealt with some of the changes that occurred to 210.12 for arc-fault circuit interrupters (AFCI) in the 2014 National Electrical Code (NEC), such as the expansion of AFCI devices to include circuits for kitchens and laundry equipmen
I made a comment while teaching a class that nonmetallic (NM) cable was not permitted in an outdoor, wet location. An attendee took exception to that statement and asked me to provide National Electrical Code (NEC) justification for the assertion.
Installation requirements for arc-fault circuit interrupters (AFCI) in 210.12 of National Electrical Code (NEC) have been modified considerably in the past three NEC cycles and have changed dramatically in the 2014 NEC.
The 2014 National Electrical Code (NEC) process received more proposals—including a total of 45 generated by the NEC Correlating Committee Task Group on direct current (DC)—and comments to insert DC into the Code than any other NEC cycle in history.
A friend of mine recently called with a question about the cover depth requirement for an underground 120-volt (V) lighting circuit installation in rigid polyvinyl chloride (PVC) conduit supplying a wet-niche luminaire in a swimming pool.
“Motor contribution” is only used in 240.86(C) in the National Electrical Code (NEC), but the NEC does not define it anywhere. A full explanation of this important electrical application is located in other publications, such as fuse and circuit-breaker protection books and articles.
As we enter the fall, crops are ready for harvest, the leaves on trees are turning color, the evenings have a slight chill, baseball season is nearing an end, football season is just getting started, and we have a new 2014 National Electrical Code (NEC).
I was involved recently in a discussion on lightning protection for various types of buildings and what standards applied to those installations or if the installations required compliance with NFPA 780, Standard for the Installation of Lightning Protection Systems; UL 96A, Standard for Installation
Many of the articles that I write for this magazine originate as questions that I receive as I travel, by phone, or come to me as emails. I can answer some of these questions very easily without much controversy by a simple reference to the National Electrical Code (NEC).
In the 2011 and previous editions of the National Electrical Code (NEC), installing low-voltage lighting in close proximity to the edge of a swimming pool was a Code violation, yet almost every backyard swimming pool with a landscaped yard has low-voltage lighting too close to the pool’s edge.
Article 424 in the National Electrical Code (NEC) addresses fixed electric space heating equipment, stating, “for the purpose of the article, heating equipment shall include heating cable, unit heaters, boilers, central systems, or other approved fixed electric space-heating equipment.” Since the sc
In the 2005 National Electrical Code (NEC) process, proposals were submitted to change the phrase “equipment grounding conductor” to “equipment bonding conductor” wherever the phrase existed throughout the NEC.