Ecmweb 21993 9 20 18wwh
Ecmweb 21993 9 20 18wwh
Ecmweb 21993 9 20 18wwh
Ecmweb 21993 9 20 18wwh
Ecmweb 21993 9 20 18wwh

What’s Wrong Here? Hint: An Alarming Installation

Sept. 20, 2018
Think you know how this installation violates the NEC?

Hint: An alarming installation

See the answer below.

I spotted this alarm bell dangling off the side of a strip mall building. I’m guessing it is probably part of a fire alarm system. The most obvious problem here is the lack of proper support for the box, which is required to be “rigidly and securely fastened in place” in accordance with the requirements in Sec. 314.23(A). The next problem requires a closer look and may not be as obvious.

The set-screw type of connector used to secure the raceway into the top of the round box is a violation of Sec. 314.15, which requires fittings installed in wet locations (such as this) to be listed for use in wet locations. This set screw connector is not listed for this wet location application.

On a separate note, Sec. 300.7(A) requires raceways that pass from the interior to the exterior of a building to be sealed with an approved material that prevents the circulation of warm air into a colder section of the raceway. This seal could be fiberglass, duct seal, foam or some other type of material that won’t harm the conductor but will minimize the chance of condensation forming inside the raceway.

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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