674f2bda48dc8f51e9fd6075 Illustrated Catastrophe 1

Illustrated Catastrophes: A Flexible Metal Conduit Calamity

Dec. 18, 2024

See the latest Code violations from NEC Consultant Russ LeBlanc.

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

A Flexible Metal Conduit Calamity

runs of FMC strewn about the water pipes and other piping systems in mechanical room

I guess the installer of this flexible metal conduit (FMC) figured securing and supporting the conduit was “optional.” I saw many runs of FMC simply strewn about the water pipes and other piping systems in this mechanical room. Section 348.30(A) requires FMC to be securely fastened in place within 12 in. of each box, conduit body, or other conduit termination. That didn’t happen here. That same Section also requires FMC to be supported and secured at intervals no greater than 41/2 ft. While portions of these conduits may be “supported,” I would not consider any of them properly “secured” other than at the connectors securing the FMC to the enclosures.

There are four exceptions allowing supporting and securing options that differ from the requirements of the general rule. However, none of those exceptions apply to any of the 3/8-in. FMC shown in this photo. In fact, 3/8-in. FMC probably should not have been used here. Section 348.20(A) places restrictions on using FMC smaller than trade size 1/2-in. There are certain scenarios described in Sec. 348.20(A)(1) through (A)(5) where 3/8-in. FMC could be used, but none of those scenarios apply to the wiring for the controls of these hot water tanks.

A Sloppy Slew of Code Violations

gaping hole bashed through the wall above the door to this electric room

Where do I even begin? There are so many problems here. I suppose the most immediate problem is the gaping hole bashed through the wall above the door to this electrical room. There is absolutely zero firestopping for this hole as required by Sec. 300.21, and smoke/fire could easily spread from one side of the wall to the other side — and all through the building. There is a variety of cables in that giant bundle (including NM cables) that are not permitted to be installed exposed in this multiple occupancy building. Section 334.10(3) requires these NM cables to be concealed within walls, floors, or ceilings providing a 15-minute finish rating. None of the NM cables or AC cables are supported and secured properly. According to Sections 320.30(B) and 334.30, these types of cables are required to be supported and secured within 12 in. of each enclosure where they are connected and at intervals no greater than 41/2 ft. Several of the red fire alarm cables have been spliced without being installed in enclosures, boxes, fire alarm devices or utilization equipment, or listed fittings in violation of Sec. 760.130(B)(1).

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.