NM under a building

[macmikeman]

I will estimate 80 per cent of the houses in Hawaii are up on 2-3 ft stilts, have nm cable run underneath, have all passed inspection, and have zero problems related to the fact that the sheath is nm cable. The other 20 per cent are on slabs and the wires are all run thru the attic.

 

[Pierre C Belarge]

I will estimate 80 per cent of the houses in Hawaii are up on 2-3 ft stilts, have nm cable run underneath, have all passed inspection, and have zero problems related to the fact that the sheath is nm cable. The other 20 per cent are on slabs and the wires are all run thru the attic.

Thats because the squirrels, rats and mice are all on vacation in Hawaii.

 

[ivsenroute]

Exterior and damp. NM not allowed.

Attics are inside the building envelope and when properly vented are not damp locations.

The soil below homes is always damp and releases moisture directly under the house into this crawl area.

Crawlspaces that are enclosed, have a vapor barrier and a dehumidifier to condition the air are not damp and within the building envelope, not outside.

This case as described by the OP is not a candidate for NM in that location.

 

[macmikeman]

Thats because the squirrels, rats and mice are all on vacation in Hawaii.

We stop squirrels at the border.:wink: FAMILY Sciuridae Sciuridae (all in family, except the following two species for exhibition in government zoos only: Callosciurus prevosti (squirrel, prevost's) and Sciurus variegatoides (squirrel, variegated) and except all species in the genus Marmota for research in government universities only) ?4-71-6

 

[radiopet]

In the specific example given, I would consider this outside and a damp location simply due to the fact it is not within the protected envelope. As for a crawl space, the location could be both damp or dry depending on existing conditions but in the OP's question being one that it is outside and two being outside yet covered is still a damp location.

Location, Damp. Locations protected from weather and
not subject to saturation with water or other liquids but
subject to moderate degrees of moisture. Examples of such
locations include partially protected locations under canopies,
marquees, roofed open porches, and like locations,
and interior locations subject to moderate degrees of moisture,
such as some basements, some barns, and some coldstorage
warehouses.

Yeah....I would call it a damp location before I would call it a dry or wet location if I had to make the call. It has the twofecta going for it...Outside and Damp Location.....

 

[K8MHZ]

I just picked up some NM today and this thread made me look closer to the label. It said that the product was for use 'indoors'. It did not say 'inside'. So I would gig it on the fact that the location was not indoors, ie, where is the door?? Plus, UF is not that much more expensive, just a bugger to make connections with.

That being said, I have seen NM used outside in some nasty wet locations here in Michigan that worked fine for decades. To Mother Nature copper is copper, no matter how pretty it is wrapped....

 

[K8MHZ]

In the specific example given, I would consider this outside and a damp location simply due to the fact it is not within the protected envelope. As for a crawl space, the location could be both damp or dry depending on existing conditions but in the OP's question being one that it is outside and two being outside yet covered is still a damp location.

Location, Damp. Locations protected from weather and
not subject to saturation with water or other liquids but
subject to moderate degrees of moisture. Examples of such
locations include partially protected locations under canopies,
marquees, roofed open porches, and like locations,
and interior locations subject to moderate degrees of moisture,
such as some basements, some barns, and some coldstorage
warehouses.

Yeah....I would call it a damp location before I would call it a dry or wet location if I had to make the call. It has the twofecta going for it...Outside and Damp Location.....

Agreed. Excellent interpretation.

 

[arnettda]

Thanks for all your replys. Her is another question. If you can not put Nm inside of a conduit outside. Can you run Nm into the back of a 3R panel installed outside? Would this not also be considered a damp location?

 

[480sparky]

Thanks for all your replys. Her is another question. If you can not put Nm inside of a conduit outside. Can you run Nm into the back of a 3R panel installed outside? Would this not also be considered a damp location?

The 2008 NEC only defines the inside of raceways installed in wet locations to be wet locations. 300.5(B) and 300.9. It does not define the interior of a box or panel as such.

If the inside of a panel would be considered a damp or wet location, you would not be able to put breakers in it.