All references are based on the 2023 edition of the NEC.
Poor Choice of Fittings
It is permitted to install electrical metallic tubing (EMT) outdoors in a wet location [Sec. 358.10(A)(2)]. However, using setscrew fittings and couplings — like the type shown in this photo — in wet locations is not permitted, since they are not designed and rated for use in these locations. The EMT in this photo has rusted to the point where the conductors are protruding from the bottom of the raceway. The setscrew fittings can allow water to enter the raceway and enclosures, causing severe corrosion problems, as illustrated here. Wet location-rated compression-type fittings are available for EMT and would have been the better choice for this installation.
Another problem with the installation is the lack of clips or any other supports for the EMT. There are none! Sec. 358.30(A) requires EMT to be securely fastened in place within 3 ft of each cabinet, box, conduit body, or other tubing termination, and at intervals not exceeding 10 ft. This raceway was certainly not originally installed and arranged to drain as required by Sec. 225.22. The installer who performed this work may want to reread the requirements for installing EMT outdoors in Art. 225 and Art. 358.
Wrong Wiring Method for Outdoors
I noticed the wiring on this sign while visiting a local seafood restaurant. The bright yellow cable grabbed my attention as I walked from my car through the oceanside parking lot. When I took a closer look at the cable, my suspicion that it might be an NM cable was confirmed.
Type NM cables cannot be installed outdoors. Section 334.12(B)(4) clearly states that Type NM cable is not permitted to be installed in damp or wet locations. This is certainly a wet location. There is also a gray UF cable installed behind the yellow NM cable. UF cable is permitted in this outdoor wet location; however, some protection from physical damage should have been provided, since this cable could be stepped on, kicked, bumped, or otherwise damaged. Jamming two cables into a connector designed for only one cable is a violation of Sec. 110.3(B). I’m not sure if those blue insulated NM cable staples are suitable for installation in direct sunlight or this outdoor wet location. Lastly, the buried PVC junction box is probably fine for installation in wet locations, but I am not sure if it is identified or listed for being directly buried in the ground.
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.