Illustrated Catastrophes: The Perfect Name

June 1, 2022

See the latest code violations from NEC Consultant Russ LeBlanc.

All references are based on the 2020 edition of the NEC.

The Perfect Name

The name of this local ice cream shop is also the perfect description of the luminaire installed to light up its sign. When done correctly, a rigid metal conduit (RMC) can be used to support a box or other enclosure supporting a lampholder or luminaire. This installation, however, is not done correctly. Section 314.23(F) permits enclosures that support lampholders, luminaries, or other equipment to be supported by threaded raceways, such as RMC or intermediate metal conduit (IMC) under the following specific conditions: the enclosure must have a volume of 100 cu in. or less; two conduits must be treaded wrench tight into the enclosure; and each conduit must be secured within 18 in. of the enclosure. The conduits supporting the luminaire in this photo do not comply with Sec. 314.23(F). Exception No. 2 in Sec. 314.24(F) provides alternative support requirements for boxes supporting luminaires, but the installer did not follow those rules either. To comply with Exception No. 2, six specific conditions must be met. While this installation may comply with conditions 3 through 6, it does not comply with conditions 1 and 2.

luminaire installed above ice cream shop sign

Boiler Room Blues

I found this mess in the boiler room of an apartment building. Whoever wired the fan and thermostat took no care at all when running the MC cables. They are flung everywhere and are nowhere close to being supported or secured correctly. This installer secured the MC cables to fire sprinkler pipes, heating pipes, electrical metallic tubing (EMT) raceways, and whatever other convenient thing he or she could find. Section 300.11(C) generally prohibits using raceways as a means of support for cables, other raceways, or any nonelectrical equipment. The EMT here is not identified as a means of support and does not comply with Sec. 300.11(C). Section 358.12(2) also prohibits using EMT to support luminaires or other equipment other than conduit bodies. Securing the MC cables directly to the structure would not have been very difficult, but this installer took the easy way out. If you look closely, you may be able to spot a black NM cable secured with cable ties to the lowest heating pipe directly above the disconnect switches. When NM cable is run exposed, Sec. 334.15(A) requires the cable to closely follow the surface of the building finish or running boards. Neither of those choices was made here.

MC cable improperly attached to electrical metallic tubing and water pipe

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.