Illustrated Catastrophes: 110.8, 300.15, 358.30, 352.30, 312.2, and 352.30

Illustrated Catastrophes: 110.8, 300.15, 358.30, 352.30, 312.2, and 352.30

More Code catastrophes uncovered and corrected in these faulty installations






All references are based on the 2011 edition of the NEC.

A Feast of Plenty

Heath Ward, a journeyman electrician/foreman, discovered this cornucopia of connectors, smorgasbord of support problems, and mix of violations in a convenience store in Dallas while disconnecting power to one area of the store for a remodel project. I’ll begin by pointing out the use of plumbing elbows incorrectly used with this PVC. Those short white elbows may be good for flowing water but are really bad for pulling wires. Section 110.8 informs us that only recognized wiring methods are included in the Code. This does not include plumbing fittings. The next violation is the use of EMT connectors on the PVC pipe and the MC cables connected to the top of the panel. This violates Sec. 300.15, which requires wiring methods to be used with fittings designed and listed for the specific wiring method installed. This could also create bonding and grounding problems for those metal cable jackets. The next violation is the lack of supports on the EMT and some of the PVC pipes. These pipes should be supported in accordance with 358.30 and 352.30, respectively, both of which require the pipe to be supported within 3 ft of the enclosure to which it is connected.


A Floppy "Disc-Connect"

This photo was sent in by Larry Ward, a senior electrical engineer with Hooker/DeJong, Inc. in Muskegon, Mich. He found the disconnect for this rooftop air-conditioning unit just flopping around like a newly caught fish. Apparently, using proper supporting techniques were optional for this installer. This disconnect is meant to be weatherproof; however, the way in which it is positioned on the roof leaves it to possibly fill with rainwater. Section 312.2 requires surface-type enclosures to be mounted and secured in a manner that will prevent water or moisture from entering the enclosure. The position and lack of support could also make it difficult for service personnel to turn it off. This could increase the shock and arc flash hazard for that person if he has difficulty disconnecting the power. Section 352.30 requires liquidtight flexible metal conduit (LFMC) to be securely fastened within 12 in. of each enclosure and supported at intervals of no greater than 4½ ft. Exception No. 2 does allow LFMC of sizes ½ in. through 1¼ in. to be unsupported for up to 3 ft from the enclosure; however, the lengths in the photo appear to be longer than these distances.

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