Opinions sought NM inside conduit outside

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Opinions sought NM inside conduit outside

  • Yes

    Votes: 18 11.3%
  • No

    Votes: 141 88.7%

  • Total voters
    159
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iwire

Moderator
Staff member
Location
Massachusetts
I have a shed in my backyard, it is unheated/unairconditioned, 8' x 10' and Romex was used. This is against the NEC since it is defined as a Damp Location?

I think an AHJ could say that it is a damp location and you would have to use UF.

as did the Romex in the conduit from my exterior panelboard up into the attic, then again in conduit down the exterior of my house and underground 4' to the shed

Those are NEC violations and should not have passed, but I know it is often done and passed.
 

iwire

Moderator
Staff member
Location
Massachusetts
Is humid and damp the same thing?

IMO yes.

Bathrooms and basements are subject to humid conditions on a regular basis yet no one claims NM cannot be used in bathrooms or basements.

NM is not normally run 'in' bathrooms it is run in the walls. ;)

IMO it would be within the AHJs authority to determine a particular basement is a damp location. In my area one persons basement is as dry as year old bread, another's persons basement is dripping water like a frosted mug.
 

220/221

Senior Member
Location
AZ
I have a shed in my backyard, it is unheated/unairconditioned, 8' x 10' and Romex was used. This is against the NEC since it is defined as a Damp Location?

Is the shed normally subject to dampness?

If so, use UF or fix the roof :grin:


If an hollow object is located in a damp location the interior of the object will also be damp

As long as the hollow object is not a panel. NM is allowed in a NEMA 3R panel but not in the conduit going to/from it. I'm just sayin.......:rolleyes:
 

iwire

Moderator
Staff member
Location
Massachusetts
As long as the hollow object is not a panel. NM is allowed in a NEMA 3R panel but not in the conduit going to/from it. I'm just sayin.......:rolleyes:

I hear you and can't disagree. :smile:


But don't you live in the desert anyway, is anything 'damp'? :grin:
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
It's been pointed out to me in the past that there is no requirement in the NEC for wet or damp location breakers. There is however a Prohibition against using NM in wet or damp locations.

110.11 Deteriorating Agents.​
Unless identified for use in
the operating environment, no conductors or equipment

shall be located in damp or wet locations

Equipment in a damp location must be identified for damp location.

If you are say that the inside of enclosures in damp locations are damp locations then it sounds like you are saying the CBs must be identified for damp locations
 

markstg

Senior Member
Location
Big Easy
Is the shed normally subject to dampness?

If so, use UF or fix the roof :grin:

Subject to dampness, I guess you could say that with Global Warming an all..but to date is not showing any signs of condensation....Tools aren't rusted, lawn mower OK. Think I'll call it a dry location.

But the exterior/underground conduit with romex....well doesn't matter what I say, and I'm not going to change it.

Oh and the roof is just fine, put it on myself after hurricane Katrina made my shed a WET location.
 

iwire

Moderator
Staff member
Location
Massachusetts
If you are say that the inside of enclosures in damp locations are damp locations then it sounds like you are saying the CBs must be identified for damp locations

I used to say that until Charlie "The Utility Guy" that also happens to be on the CMP for 240 mentioned that neither breakers or fuses are required to be listed for wet or damp locations even when installed in those areas.:smile:
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
I used to say that until Charlie "The Utility Guy" that also happens to be on the CMP for 240 mentioned that neither breakers or fuses are required to be listed for wet or damp locations even when installed in those areas.:smile:

It may be obvious to everyone but me because I didn't read whatever thread that Charlie explained it in but please help me understand.

A circuit breaker is a device. Equipment by definition included devices. 110.11 says equipment shall not be located in wet/damp areas unless identified for such....

So help me connect the dots. What is the reasoning?
 

iwire

Moderator
Staff member
Location
Massachusetts
I don't know the answer, Charlie and I did not talk about 110.11 but there is no doubt in my mind the inside of a 3R enclosure is very often a damp location.

The rusted / corroded bus bars / terminals I see prove that.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
I don't know the answer, Charlie and I did not talk about 110.11 but there is no doubt in my mind the inside of a 3R enclosure is very often a damp location.

The rusted / corroded bus bars / terminals I see prove that.

If they are in a damp location and are not identified for it I can see why they may rust. :smile: IMO violation.

What about wire nuts in these enclosures? You believe they must be indentified for wet/damp.
 

viclibo

Member
NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's not rated for wet locations!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's a fact, Jack.................so to speak.
 

220/221

Senior Member
Location
AZ
NO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's not rated for wet locations!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
It's a fact, Jack.................so to speak.


If you are referring to the original post, he didn't ask about wet locations :D

He said "outside a structure"
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
I believe the inside of a 3R enclosure is a damp location when the enclosure is located in a damp area. :grin:

Wow talk about avoiding direct questions! :grin:
Doesn't matter how many times I ask what questions, your gonna keep on say that no matter how it doesn't jive with other codes.

It may not make sense to you that inside a damp area conduit is not a damp area but you've got no code to back it.

I've got code to back the breakers and wire nuts in your outdoor enclosures need to be identified for wet/damp IF you think they are wet/damp.... of course the code doesn't say they are wet/damp in the first place so I got no problem with the wire nuts or breakers.,
 
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