6568dff87c14aa001f7422ab Illustrated Catastrophe 1

Illustrated Catastrophes: Unfinished Basement Business

Dec. 13, 2023

See the latest Code violations from NEC Consultant Russ LeBlanc.

All references are based on the 2023 edition of the NEC.

Unfinished Basement Business

It is quite common for me to find violations in unfinished basements of dwelling units. One of the more common violations I find is NM cables that have been secured directly to the bottom of joists or framing members as seen in this Photo. Section 334.15(C) addresses NM cables installed exposed in unfinished basements. It permits cables no smaller than two 6 AWG or three 8 AWG to be secured directly to the bottom of the joists when run at angles with the joists, perpendicular in this case. It requires smaller cables, such as the 12/2 or 14/2 in the Photo to be run through holes drilled through the joists or on running boards that could be secured to the bottom of the joists. I am also concerned about the use of that field-made metal cover installed on the PVC device box. Is it grounded and bonded? If so, then how? Several Sections in Art. 250 require the metal cover to be grounded and bonded, including Secs. 250.4(A)(5), 250.86, 250.110, and 250.134 for starters. Lastly, the sharp bend in the NM cable where it passes around the bottom of the joist may not comply with the bending requirements in Sec. 334.24.

Installers Cutting Corners

This is another example of an all-too-common violation I encounter. Using a raceway to support a bundle of cables in this manner is not permitted. There are several rules we can look at here. First, Sec. 300.11(C) permits raceways to be used as a support for cables but only under very specific conditions, of which, none apply here. Next, Sec. 358.12(2) prohibits using electrical metallic tubing (EMT) to support luminaires or other equipment except conduit bodies no larger than the trade size of the EMT. Additionally, Sec. 722.24(A) requires the installation of cables used for Class 2 and Class 3 power-limited circuits, power-limited fire alarm (PLFA) circuits, and Class 4 fault-managed power circuits to conform to Sec. 300.11. Section 722.24(B) also prohibits these cables from being secured to the exterior of any conduit or raceway as a means of support. For optical fiber cables, Sec. 770.133(D) prohibits this type of installation too. Lastly, for communication circuits, Sec. 800.133(C) prohibits communications wires and cables and CATV-type coaxial cables from being strapped, taped, or attached by any means to the exterior of any raceway as a means of support. Installers ignored all those rules here.

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.