Ecmweb 15559 Nec Illustrated Catastrophes August 2017 Pr
Ecmweb 15559 Nec Illustrated Catastrophes August 2017 Pr
Ecmweb 15559 Nec Illustrated Catastrophes August 2017 Pr
Ecmweb 15559 Nec Illustrated Catastrophes August 2017 Pr
Ecmweb 15559 Nec Illustrated Catastrophes August 2017 Pr

Illustrated Catastrophes: Construction Site Calamity

Aug. 23, 2017
More Code catastrophes uncovered and corrected in these faulty installations

All references are based on the 2017 edition of the NEC.

Construction Site Calamity

Generally speaking, when splices are made in wiring methods such as MC cable, AC cable, and NM cables (among others), Sec. 300.15 requires a box to be installed to protect and contain the splices. When it comes to temporary wiring, Art. 590 can amend or modify this general rule. Section 590.4(G) provides some modifications to this box requirement. Unfortunately, this installer did not quite understand the revisions made to that section of the Code.

Please be aware that a Tentative Interim Amendment (TIA) was issued for this Code Section on April 5, 2017. The original wording in 590.4(G) of the 2017 NEC allowed splices to be made without being installed in a box for temporary wiring in all locations, if the continuity of the equipment grounding conductor (EGC) was properly maintained. TIA 17-4 revised the rule into the form of an exception that applies only to splices made on construction sites. The exception in the TIA cannot be used for the construction site splices in the photo since the MC cable is not terminated in a fitting to “mechanically secure the cable sheath to maintain effective electrical continuity.” Using two metal cables terminated in a duplex connector would be one way to maintain effective electrical continuity for metal cables without the use of a box. For the situation shown in this photo, the splices need to be in a box.

Danger in Plain Sight

Oh boy! This is pretty scary looking. Someone thought wrapping cardboard around the base of this pole would be an acceptable means to provide protection for the wires and to protect the general public from making contact with the energized conductors in the base of this pole. Neither was accomplished. The wires are now exposed to the elements and present a real shock hazard to any passersby.

Metal poles used to support luminaires must have a handhole cover that is “suitable for use in wet locations” as specified in Sec. 410.30(B)(1). It’s pretty obvious that cardboard isn’t suitable for this purpose, especially once it gets wet. As evidenced in the photo, the cardboard has deteriorated to the point where it is almost gone.

I suppose we could also say the rules in Sec. 110.12(B) have been violated since the broken or missing cover adversely affects the safe operation of the equipment. I bet that Sec. 310.10(D) is also now being violated because these conductors and the wire connectors are exposed to the sun, but are probably not sunlight resistant. Unfortunately, I see cardboard used quite often as a means to provide protection. While it may prevent dust and paint spray from contaminating some equipment, it should not be used to protect people from shock hazards.

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.

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