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IAEI Magazine | Author: Frederic P. Hartwell
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Frederic P. Hartwell

Fred Hartwell served for almost ten years as the senior editor and NEC expert with EC&M Magazine. He is a nationally recognized NEC consultant and trainer and holds a master electrician's license in Massachusetts. He is a founding member and former secretary of the Western Massachusetts Chapter of the IAEI. He is the secretary of the Massachusetts Electrical Code Advisory Committee, and is now in his fifth cycle as a special expert and principal on CMP-9. He is the author of Practical Electrical Wiring, 18th edition, and Wiring Simplified, 40th edition. He can be reached at 413-256-6232 or at


Sizing Conductors for All Load Conditions

One of our primary responsibilities in the electrical trade is to select electrical conductors, and one of the primary responsibilities of electrical inspectors is to judge those selection decisions properly. Recognizing the importance of this issue, the task group appointed to review Article 220 for the 2005 NEC decided to recommend adding a new Example 3A to Annex D covering this topic. It does not focus on load calculations but on conductor selection instead. Unlike most examples, the loads are stipulated,1 the context is industrial, and the distribution is 480Y/277V. The proposal has been endorsed by the NEC Technical Correlating Committee and accepted by CMP-2, subject to public comment as in the case of all proposals. This article uses the setup illustrated in the proposed example (see figure 1 for a visual reference) to present the concepts that need to be mastered.

Using Device Boxes in Ceilings

If you install a device box in a ceiling, can you mount anything to it other than a blank faceplate? The National Electrical Manufacturers Association (NEMA) for the 2005 NEC is attempting to clarify that you can mount a "device, smoke detector, carbon monoxide detector, or similar product” to a device box in a ceiling, as long as it does not weigh over 3 kg (6 lb). The comments from the NEMA representative and subsequent comments from contractor members of the panel (at the January meeting just concluded) suggest that large numbers of inspectors are saying no to this practice.

Inspecting Electrical Renovations

As buildings age, their electrical systems age with them. Renovating those older systems adds flexibility through modern wiring practice and increases safety. However, the electrical contractor and the authority having jurisdiction need to agree on the ground rules that will apply to the construction. This article has two purposes. First, it looks at some general principles of responsibility for National Electrical Code compliance in renovation projects, and then it takes a practical look at construction issues that often result in NEC application controversies during renovations.