What's Wrong Here?

What’s Wrong Here? Hint: A Not-So-Underground Installation

Dec. 26, 2024

Think you know how this installation violates the NEC?

Hint: A not-so-underground installation.

The PVC box doesn’t look too bad, but the rigid PVC conduit can’t seem to make up its mind on whether it is an underground installation or an aboveground installation. Maybe it is a little of both? For the underground portion of the PVC conduit, Sec. 352.10(H) requires this conduit to comply with either Sec. 300.5 or Sec. 305.15 as applicable. Section 305.15 applies to circuits over 1000V AC or 1500V DC. Section 300.5 applies to lower voltages and is applicable in this case.

Table 300.5(A), Column 3 requires a minimum cover depth of 18 inches for this rigid PVC conduit. This conduit is buried way too shallow. In several places it is not buried at all! Since the aboveground portions of the PVC conduit are subject to damage by being stepped on, or driven over by kids on bikes, or any other types of damage, schedule 80 PVC conduit must be used as required by Sec. 352.12(C) and Sec. 352.10(K).

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.