300.9

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pete m.

pete m.

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Ohio
Looking for some opinions....

Scenario: Schedule 40 PVC ran under the floor decking of a covered porch that contains a 12-2 NM cable. By definition this wouldn't be a "location, wet".

Does anyone feel that the interior of the raceway could be considered a "location, damp" thus not allowing the installation of the NM cable?

Thanks, Pete
 
I know PVC won't keep water out if it is buried. I think it would stay dry if properly glued in a damp location. So my vote is inside the pipe is a dry location.

I probably wouldn?t install NM cable in that location in case several inspectors have different opinions. One inspector in my town might pass it and another one fail it.
 
There is no question that if the pipe is outdoors then the conduit is in a wet location. Use UF cable or thwn with jb's.
 
Dennis Alwon said:
There is no question that if the pipe is outdoors then the conduit is in a wet location. Use UF cable or thwn with jb's.
Click to expand...

I should have added that I'm asking the question in relation to an inspection I conducted. I initially defected the job but after a more careful reading of the verbiage in 300.9 I'm not so sure that I shouldn't call the contractor and tell him to ignore that particular defect notice.


300.9 Raceways in Wet Locations Above Grade.Where raceways are installed in wet locations abovegrade, the interior of these raceways shall be considered to be a wet location. Insulated conductors and cables installed in raceways in wet locations abovegrade shall comply with 310.8(C).


I don't think that the raceway will be subject to saturation or in an unprotected location exposed to weather. So I am wondering now if the interior of that raceway could be considered "damp".

I need to keep in mind, for my posts, that nobody can hear what I'm thinking...:D

Pete
 
Also realize that nm cable cannot be installed in a damp location. IMO, this would be a hard one to get by on an inspector. Personally, I think most crawl spaces are damp location so I don't see why this is the case.
 
One interpretation I got was on my sons house. I installed the hinged recpt. covers on the recpts. under the covered porch. Inspector got me on that. When I ask he stated that even though they were under a covered porch they were subject to blowing rain and considered at wet location.
 
pete m. said:
I should have added that I'm asking the question in relation to an inspection I conducted. I initially defected the job but after a more careful reading of the verbiage in 300.9 I'm not so sure that I shouldn't call the contractor and tell him to ignore that particular defect notice.


300.9 Raceways in Wet Locations Above Grade.Where raceways are installed in wet locations abovegrade, the interior of these raceways shall be considered to be a wet location. Insulated conductors and cables installed in raceways in wet locations abovegrade shall comply with 310.8(C).


I don't think that the raceway will be subject to saturation or in an unprotected location exposed to weather. So I am wondering now if the interior of that raceway could be considered "damp".

I need to keep in mind, for my posts, that nobody can hear what I'm thinking...:D

Pete
Click to expand...

Take this on the fact I have not seen the installation, It is not just that the pipe may get wet from rain or spray or how ever, the conductor is going to run at a different temp then the outside air. The temp differential can cause convection and condensation inside the pipe. Once it is wet inside the pipe the water will be there for a long long time.
This also happens when a pipe runs from a cold area to a hot area with out a seal in the conduit, like a pipe in an attic running to a light box in a ceiling, if it gets cold enough it will drip from the light box.
I think you call is correct, I wouldn't loose sleep over it either way.
 
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