When comparing other opinions on this subject, I'm having trouble deciding whether or not a J-box mounted in the brick or a J-box mounted to a wooden stud on an exterior wall of a building is considered a wet or a damp location. Based on the new regulation in 334.12(B)(4), we might be in trouble using NM cable for wiring in these boxes. This would come into play for mounting luminaries or weather proof receptacles. What is the opinion of the inspectors?
I have been asking that question for years (where does the "wet location" area start) without a solid code defining answer. I suppose they leave it to the AHJ.
How about a pancake box, surface mounted, to receive a coach light on the side of a block garage? That was one that goes back and forth because they usually serve it with a sleeve of smurf from the top of the poured tie beam, through the grouted cell to the pancake. Can they run romex in that pipe or does it have to be UF or THWN? Answer ... Which county are you in?
Besides the items mentioned above, I've seen plenty of surface mounted HVAC disconnects and Spa disconnects with NM entering the backside. Not one of them exhibits any problems. True, it is a technical violation, but not one I'd lose any sleep over.
Few things are harder to put up with than the annoyance of a good example.
Yes- Welcome Larry. As for would I write a violation, No, but if one were a purist and there out there, it is a violation. I do think this puts an end to contractors installing NM cable in conduit outdoors. 300.9 clearly says raceways and the last time I looked a box is not a raceway. 300.5(B) for underground installations clearly says raceways and enclosures. Our friend Charlie Trout has a different view of this subject.
I see the real issue as whether the RX will wick up water. That is the main thing that separates NM from wet location cables, the kraft paper packing. I would be a lot more concerned if the box was fed from below than from above. I doubt it has ever been a huge problem but the NEC is packed with unlikely "what ifs".
Greg, I agree with you on the wicking issue however, the NM cable I see lately has no kraft paper anymore. So we are dealing with an outer plastic jacket and conductors that are not rated for wet or damp location. Conventional understanding is that the conductors are THHN/THWN but they are not marked that way on the jacket or on the conductors. The specs say only that they are to be rated for 90 degrees. and suitable for dry locations. So we are down to is the box set in the exterior wall facing the exterior of the building a dry location.