All references are based on the 2014 edition of the NEC.
Fire in the Hole
A customer called to complain that his outside plugs weren’t working. I found this disaster while troubleshooting this circuit. The receptacle wasn’t working, but, believe it or not, the circuit feeding this GFCI receptacle was still energized and supplying power to it. The receptacle was destroyed from arcing and sparking connections. Water and moisture had gotten into the box because the installer didn’t use the correct screws for installing the receptacle or the box cover.
In the photo, you can see the large hex head screws that were used for attaching the receptacle yoke to the box. Using these ridiculously large self-tapping screws is a violation of Sec. 406.5 because they were not the type of screws originally supplied with the receptacle, nor were they machine screws with 32 threads per inch. The same type of self-tapping screws was also used to attach the cover to the box. These overly large screw heads prevented the cover from seating properly on the receptacle, allowing water to seep in and destroy the receptacle.
Luckily, this was installed in a granite surface; otherwise, this could have become a real disaster if this were located adjacent to a combustible surface.
This Won’t Weather the Storm
Apparently, this installer had no concerns about the effects the weather could have on this installation. It looks as if none of the equipment used for this receptacle installation is rated to be used in this wet location.
Section 406.9(B) requires 15A or 20A receptacles in wet locations to be installed in an enclosure that is weatherproof, whether or not a cord-cap is plugged into it. Where 125V receptacles are installed in wet locations, they must be listed as weather-resistant (WR) type receptacles. Boxes installed in wet locations must be listed for use in these locations as required by Sec. 314.15. Neither this box nor its cover is made for this wet location. As shown in the other Illustrated Catastrophes photo (above), moisture can destroy receptacles if they are not properly protected.
Another problem I notice is the wiring method used to supply this receptacle. MC cable used in wet locations must include a corrosion-resistant jacket over the metallic covering as specified in Sec. 330.10(A)(11).
Lastly, I question the supporting means for this box. I’m not so sure those black cable ties will provide rigid and secure support as required by Sec. 314.23(A).