What is in this article?:
- What's Wrong Here? July 2010
- Find the Answer
Here’s your chance to moonlight as an electrical inspector and second-guess someone else’s work from the safety of your living room or office. Can you identify the Code violation(s) in this photo?
Find the Answer
How well do you know the Code? Think you can spot violations the original installer either ignored or couldn't identify? Here's your chance to moonlight as an electrical inspector and second-guess someone else's work from the safety of your living room or office. Can you identify the Code violation(s) in this photo?
‘TELL THEM WHAT THEY'VE WON…’
Using the 2008 NEC, correctly identify the Code violation(s) in this month's photo — in 200 words or less — and you could win something to put in your toolbox. E-mail your response to firstname.lastname@example.org, and we'll select three winners (excluding manufacturers and prior winners) at random from the correct submissions. Winners will receive a set of insulated hand tools from Ideal Industries, Inc., valued at more than $125. (Please allow six to eight weeks for delivery of tools.)
This month's winners were: Timothy F. May, master electrician, Westphal & Co., Evansville, Wis.; Ted Worst, engineer, Allied Electric, Inc., Grand Rapids, Mich.; and Bill Moore, owner, Northfield Electric, New York, N.Y.
The first violation is the use of an EMT connector to secure the Type MC cable to the enclosure. Use of the EMT connector with the Type MC cable violates 300.15. The second paragraph of this section says, “Fittings shall be used only with the specific wiring methods for which they are designed and listed.” That wording is very restrictive, and the use of any fitting that is not “designed and listed” for the wiring method in question constitutes a Code violation.
Another violation is use of a 43 1½-in.3 square box for seven No. 12 conductors and two devices. As shown in Table 314.16(A), such a box may contain up to nine No. 12 conductors. But Part (4) to 314.16(B) says, “For each yoke or strap containing one or more devices or equipment, a double volume allowance in accordance with Table 314.16(B) shall be made for each yoke or strap based on the largest conductor connected to a device(s) or equipment supported by that yoke or strap.” This requires four additional No. 12s be added to the seven No. 12s that actually enter the box for a total of eleven No. 12s, which means the box is overfilled. It should be noted that although 314.16(A) permits a plaster ring to be considered in the overall volume of the enclosure, such consideration may only be given where the plaster ring has its volume marked on the ring. Because we can't see the marking, we can't add any volume to the box in question.
Some noted that the box should have a barrier, because there are orange-colored conductors within the enclosure, which is the color coding typically used for 480/277V system conductors to satisfy 404.8(B). That section states, “A snap switch shall not be grouped or ganged within the same enclosure with other snap switches, receptacles, or similar devices, unless they are arranged so that voltage between adjacent devices does not exceed 300V, or unless they are installed in enclosures equipped with identified, securely installed barriers between adjacent devices.” In this case, the conductors are all operating at 120V to neutral, so there is no violation of 404.8(B). However, the means of branch circuit conductor identification required by 210.5(C) does not seem to have been satisfied.