Damp location?

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Would a piece of EMT installed on the exterior of a home using raintight fittings be considered a damp location?
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Kind of depends on where the house is.

Is the area normally subjest to dampness?

My house is not normally subject to dampness. Normally it's bone dry here.
 
ishium 80439 said:
So let me take this a step further. If you install a surface mount weatherproof box fed through the wall and use NM to feed, say, a GFI, does that mean that installation is in violation because you are using NM in a wet/ damp location?
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IMO, No. The nm is not in the box just the conductors are. Others in this Forum may

feel differently.
 
It depends on whether you enter the back of the box with nm, or feed through conduit. When feeding an outside unit, I stub NM through wall straight into back of disconnect, then from there I run THHN in liquitite. NM in liquitite is illegal. It's not rated for damp locations, and if you strip it out of the sheath,,,then it has no ratings, so the transition to THHN is the legal way to do it. NM in PVC, EMT, FMC, outside is illegal. It has NOTHING to do with where the house is,,,,outside is outside
 
If NM cable is not permitted to enter the back of an outdoor box then Arlington will soon be out of business.

Siding%20Box%20Kits%20GFCI.jpg
 
ishium 80439 said:
So let me take this a step further. If you install a surface mount weatherproof box fed through the wall and use NM to feed, say, a GFI, does that mean that installation is in violation because you are using NM in a wet/ damp location?
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mcclary's electrical said:
His question was not about entering the back of the box,,,it was talking about nm in conduit.
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Actually he said it. ;)
 
Sorry if I caused confusion. I'm just trying to figure out consistency. If NM is illegal in exterior conduit, and when it is stripped out it has no rating (and therefore is not in compliance) than doesn't that mean that you can't have NM enter the back of an exterior box? And to go further doesn't that mean that exterior panels would also be in violation?

I may be missing something but I didn't see anything in 334 to the effect of "damp/ wet locations as long as the cable terminates in that box". If once it is outside it is a wet location and it is not allowed in a wet location than it seems to me that there are oodles of non-compliant work out there that has been signed off on as OK.
 
ishium 80439 said:
Sorry if I caused confusion. I'm just trying to figure out consistency. If NM is illegal in exterior conduit, and when it is stripped out it has no rating (and therefore is not in compliance) than doesn't that mean that you can't have NM enter the back of an exterior box? And to go further doesn't that mean that exterior panels would also be in violation?

I may be missing something but I didn't see anything in 334 to the effect of "damp/ wet locations as long as the cable terminates in that box". If once it is outside it is a wet location and it is not allowed in a wet location than it seems to me that there are oodles of non-compliant work out there that has been signed off on as OK.
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I would not spend too much time on dealing with consistency while using the NEC.

Installing NM cable in a raceway outside will not be treated by the NEC the same as installing NM into an enclosure that is mounted to the outside wall of a building or structure.
NM cable is not permitted to be installed in a raceway outside, but it is generally accepted installed to an enclosure mounted on an outside wall.

I have read on this site that there are jurisdictions/inspectors who treat this subject differently, so ask your inspector what he is looking for.
 
Worse than consistency, I'm about to look for practicality. What is the arguement that NM is good in a weathertight enclosure (ie panel, box etc) but not a weather tight conduit? It seems all out or all in.

Here is the actual situation I've encountered: We relocated a panel around the corner from it's original location- linereally it's about 6' away from where it was. We mounted a trough at floor joist height, brought all of the BC's into the trough and passed them through 2" offset nipples into the panel and terminated directly to the panel. It seems (I've not yet talked to him personally, just going by the correction notice and what the GC said) that he is saying that coming into the gutter is fine, but once we pass through the nipples we have a violation. I'm trying to find out how others would view this.

As an aside, from a quality perspective, it's my opinion that the installation as is, is a better solution than putting a million splices in the gutter just so we can run the final 2' in THHN.
 
What it comes down to is that, if they call you on it, you will probably have to comply.

The only ammunition you have is the interpetation of a damp/wet location. "Normally subjest to..."

Here in the desert, because dampness/wetness is almost non existant, they still allow this installation.
 
ishium 80439 said:
Worse than consistency, I'm about to look for practicality. What is the arguement that NM is good in a weathertight enclosure (ie panel, box etc)
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but not a weather tight conduit?  It seems all out or all in.
Here is the actual situation I've encountered: We relocated a panel around the corner from it's original location- linereally it's about 6' away from where it was. We mounted a trough at floor joist height, brought all of the BC's into the trough and passed them through 2" offset nipples into the panel and terminated directly to the panel. It seems (I've not yet talked to him personally, just going by the correction notice and what the GC said) that he is saying that coming into the gutter is fine, but once we pass through the nipples we have a violation. I'm trying to find out how others would view this.

As an aside, from a quality perspective, it's my opinion that the installation as is, is a better solution than putting a million splices in the gutter just so we can run the final 2' in THHN.
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When a conduit is buried IT CONDENSATES. I've heard of guys saying "if you use primer and then glue, the PVC will be dry,,,,BOLONY,,,it doesn't matter if you use primer then glue,,,,ALL UNDERGROUND PVC is wet inside.
 
I said I would say it here in the other thread - so I am....
Other thread... said:
ishium 80439 said:
When coming up in the trade in CT I never saw a panel installed w/ the chase nipple method. Than again I don't think I ever saw an exterior loadcenter. Here in CO it is the norm to have an exterior loadcenter and the chase nipple method is prevalent in the entire metro area. When one is doing a service upgrade there is really not a whole lot of choice but to replicate the same method (unless you are willing to do lots of damage to the interior finishes. I see lots of new work still being done this way but I've never really liked it. On new work I always put the panel inside and enter via the methods discussed (I've never really understood why people like the panels outside).

E57, if I understand your description, you set a box, drop the EGC's and turn the other conductors through a nipple and terminate them in the panel. Isn't this a violation by having the stripped NM in exterior conduit? The reason I ask is I have a thread going where I did something similiar (brought the NM into a trough and turned the conductors up through 2" chase nipples) and was shot down for the conductors being in a wet location.
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Excellent point, and no I have never been hit on that.... IMO if you were going to get hit on that - you should also be hit on that for taking them to an exterior panel in the first place. So I see no difference in taking them to a box first then a short distance to the panel. Others may disagree... But otherise you are almost forced to use a large KO, as often that is what is given on the back of most panels - often leaving very little space for much else... That one could secure correctly. And the cable jacket, and its conductors are still outside - be it in a cabinet or a J-bx. If you're getting hit on that - then everyone should be bringing UF out any exterior panel - right?

Sometimes you have to break some eggs - and I'll be happy to say that in the other thread too.
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Can someone point to where the conduit, or J-bx or cabinet requires the conductors be of a certain type? Except for conduits underground etc, the inside of conduits could only ever be at worst a damp location....

Now here's where an install like this may have some legs for the Inspector...

It depnds on which code cycle you are on????????????

There is a change in '08 that could doom it.... (I am on the '05 for the time being....)

334.12(B)4 in the '05 NEC said:
Where exposed or subject to excessive moisture or dampness
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Up to interpetation IMO.... Pretty vague....

334.12(B)4 in the '08 NEC said:
In wet or damp locations.
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:roll: That could getcha... But IMO if they choose to enforce that - then all exterior panels need to have UF cable or some other wet/damp location rated wire or cable - just to get into a box or cabinet. For that matter into any exterior light fixture, or even still - any damp location, say a bath fixture....

Also, IMO if they are going to enforce that the conducors in NM are stripped from the jacket are not listed for wet or damp locations - challenge them to find documentation for it - I would love to know....
 
e57 said:
Can someone point to where the conduit, or J-bx or cabinet requires the conductors be of a certain type? Except for conduits underground etc, the inside of conduits could only ever be at worst a damp location....
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300.9 states that the interiors of raceways installed in wet locations above grade shall be considered wet locations. It also says insulated conductors in said raceways shall comply with 310.8(C), which lists the characteristics and types of insulation.

It should give a ruling on conductors in enclosures in wet locations above grade, but doesn't.
 
Barjack said:
300.9 states that the interiors of raceways installed in wet locations above grade shall be considered wet locations. It also says insulated conductors in said raceways shall comply with 310.8(C), which lists the characteristics and types of insulation.

It should give a ruling on conductors in enclosures in wet locations above grade, but doesn't.
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Sorry buddy both of those stated are not in MY code book... I'm still on the '05 ;) - Guess I have some learnin to do in a few years.... :roll: I'll also have to up-date a few of my common practices too...

But chalk another up for the inspector mentioned for the OP....
 
I had this job re-inspected and a different inspector came out. The first one is an unpleasant man with whom you can discuss nothing. The 2nd one explained that Denver has basically made an arbitrary ruling about how to handle this situation. It is not written anywhere but they will allow NM to enter an enclosure but not to pass through anything else. We pointed out to him that if you go to the UL site it states that the conductors are essentially THHN (thermoplastic, nylon, heat) and questioned why a stripped cable, which is now essentially a set of THHN conductors, was not allowed to pass through. He stated that if we could get the UL spec's along with the manufacturer's spec's that they (at least he) would take this into consideration in the future.

It seems that even a largish city like Denver still plays the game of "it's not in the book this way but...."
 
The same issue would go for exterior, house mounted lighting fixtures. The box is inside the wall, the NM feeding the "exterior" fixture.

If you are running exterior EMT, it is considered a damp location, and requires raintight fittings. Within that raceway, THHN should be used. At the exterior mounted FS box, NM should be permitted to run into the box provided the entry is sealed with ductseal or caulk to prevent water entry.

As you know, NM is not allowed in raceway, unless the run is short and for damage protection. Also, NM cannot be used outdoors. So, I think if it transitions immediately from inside a structure - directly into an FS Box mounted on the outside wall, and then THHN is used throughout the exterior EMT raceway, the install would be compliant in *most* jurisdictions.
 
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