Ecmweb 7837 Nearmiss595

What’s Wrong Here? Hint: A Near Miss

Oct. 21, 2015
Can you identify the Code violation(s) in this photo?

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. It's your turn to identify the violation.

Hint: A near miss

Find the Answer

Whew! That was a close call. A couple of those screws almost hit this EMT, which was secured directly to the underside of this corrugated sheet metal roof decking.

When repairing or replacing roof insulating material, roofers often need to use very long screws to ensure they penetrate the lowest portions of the corrugated deck. This is why Sec. 300.4(E) requires raceways, boxes, or cables to be spaced at least 1 ½ in. from the lowest surface of the roof decking. An Exception in this Section of the Code permits rigid metal conduit (RMC) and intermediate metal conduit (IMC) to be secured without the 1 ½ in. spacing requirements.

Section 358.12(1) states that EMT shall not be used “where, during installation or afterward, it will be subject to severe physical damage.” I think a screw penetrating right through the EMT would be considered “severe physical damage.” This EMT should have been spaced down from this roof deck.

Similarly, Sec. 410.10(F) applies the same 1 ½ in. spacing requirements to luminaires installed beneath metal-corrugated sheet roof decking.

About the Author

Russ LeBlanc | Owner

Russ started in the electrical trade as an apprentice in 1985. He worked his way up to become a Journeyman Electrician and then eventually became a Master Electrician and Licensed Construction Supervisor. In 1999 Russ become an Electrical Instructor for The Peterson School of Engineering in Massachusetts where he developed his passion for teaching, and quickly became Department Head of Electrical Instruction. Russ has taught thousands of apprentices, electricians, engineers, inspectors, and other electrical professionals during his career as an instructor. He continues to provide electrical professionals with Electrical Code seminars, Arc-Flash Awareness training seminars and educational material through his LeBlanc Consulting Services in North Reading, MA whose specialty is educating electricians. He has been an active member of the NFPA Electrical Section and has authored hundreds of National Electrical Code proposals and comments which have become Code rules to improve the safety for the electrical industry. Russ is also an IAEI certified Electrical Inspector.

Please visit www.russleblanc.net for more information.

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