Ecmweb 5679 308ecmicpic1b
Ecmweb 5679 308ecmicpic1b
Ecmweb 5679 308ecmicpic1b
Ecmweb 5679 308ecmicpic1b
Ecmweb 5679 308ecmicpic1b

Illustrated Catastrophes: 362.12(8), 362.30(A), 334.12(B)(4), 300.9, 340.12(10), 300.5(D)(1), 300.5, 300.5(D)(4), and 314.23

Aug. 15, 2013
More Code catastrophes uncovered and corrected in these faulty installations

What a Rush!

Apparently, the person who installed the wiring for this air-conditioning  (A/C) unit didn’t know the permitted uses for ENT or NM cable. A quick check of 362.12(8) of the 2011 NEC informs us that ENT is not permitted to be installed where it will be exposed to direct sunlight, unless it is identified as sunlight-resistant. Upon close investigation, I did not find any markings or labels on the ENT to indicate that it was suitable for direct sunlight.  In addition, the supporting methods for the ENT are questionable, since the raceway is attached with cable ties to the refrigerant lines instead of being securely fastened to the structure as intended by 362.30(A). If you take a closer look, you’ll see the ENT has been used as a sleeve for NM cable. This is a clear violation of 334.12(B)(4), because NM cable is not permitted to be used in wet locations. According to 300.9, the interior of this aboveground raceway is considered a wet location. Upon even closer examination, we can see the LFMC from the disconnect is not properly supported either. The end near the A/C unit is dangling in the air and not even connected to the unit.

Duct Tape: Use No. 1,001

According to 340.12(10) of the 2011 NEC, you shall not install UF cable where it’s subject to physical damage. Similarly, 300.5(D)(1) requires direct-buried cables to be protected from physical damage with a raceway or enclosure where the cable emerges from grade. This protection must extend to at least 8 ft above finished grade. The protection method must also extend below grade to the minimum cover depth required by Table 300.5, but does not need to exceed a maximum depth of 18 in. The broken Schedule 40 PVC pipe provides a clue that this equipment is exposed to physical damage. As noted in 300.5(D)(4), rigid metal conduit, intermediate metal conduit, or schedule 80 PVC should have been used instead of schedule 40 PVC to protect the conductors inside this conduit. Last but not least, while the use of duct tape may be a clever way to support the box and the pipe and cables, it could certainly be considered a Code violation too. Section 314.23 has many requirements for properly supporting boxes, including using nails, screws, brackets, framing members, or even support wires, but does not recognize the use of duct tape as a securing and supporting means.

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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