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Posted By: George Little Wet and Damp Location - 04/09/10 09:52 PM
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?
Posted By: HotLine1 Re: Wet and Damp Location - 04/10/10 12:09 AM
George:
Ah, splitting hairs again?

IMHO, as the NM is 'terminated' in the box (jacket removed), and it's been an accepted practice, I have no issue with it.

There are many installations as you describe, that have been 'in service' for many, many yeras with no issues, so what is the justification for any 'change'.

Now, install a extension box on the recessed box, install a raceway from that box to another location (all surface mounted), and sleeve NM in the raceway, that I have an issue with.

Posted By: gfretwell Re: Wet and Damp Location - 04/10/10 06:31 AM
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?
Posted By: Tom Re: Wet and Damp Location - 04/10/10 05:19 PM
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.
Posted By: larrypro Re: Wet and Damp Location - 04/10/10 06:57 PM
Hi George,I would be hard pressed to write a violation for either installation.I think some of the people on code making panel's have way too much time on their hands.Larry Dependable
Posted By: HotLine1 Re: Wet and Damp Location - 04/10/10 07:00 PM
Larrypro:

Welcome to ECN forums, if no one else already has not said that.

Nice comment!
Posted By: George Little Re: Wet and Damp Location - 04/11/10 03:28 AM
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.
Posted By: gfretwell Re: Wet and Damp Location - 04/11/10 03:54 AM
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".
Posted By: George Little Re: Wet and Damp Location - 04/11/10 02:13 PM
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.
Posted By: renosteinke Re: Wet and Damp Location - 04/11/10 09:25 PM
Welcome to the brave new world of the 2008 NEC!

Heck, ever ordinary crawl spaces can be honestly considered out-of-bounds for Romex, the way it's now worded. If it might ever be 'damp,' Romex is out!

Do I agree? Hell No! I have to wonder what the code panel was smoking!

Am I worrying too much? Not at all .... the 'home inspection' crowd is already having orgasms over these new 'violations.'
Posted By: gfretwell Re: Wet and Damp Location - 04/12/10 12:14 AM
The "Romex" branded NM-b still has the paper. I have some I got last month.
I thought NM without the paper was NM-c
Posted By: George Little Re: Wet and Damp Location - 04/12/10 03:42 AM
Greg- to my understanding no one is manufacturing NMC. We had a presenter at an IAEI program a few years ago and he said that there isn't any demand for it. If someone know differently I would appreciate an update.
Posted By: gfretwell Re: Wet and Damp Location - 04/12/10 07:32 AM
I have never seen NM-c either. The wire manufacturers link you to UF when you look for it.
I just thought NM-c would be NM without the paper.
I think I heard about it from one of our northern neighbors.
Do they have NM-C in Canada?
Posted By: HotLine1 Re: Wet and Damp Location - 04/12/10 02:22 PM
FWIW, I have not seen any NM without paper, nor have I seen any NM-C here.

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