334.12(B) Common Violation….

AC\DC

Senior Member
Location
Florence,Oregon,Lane
Occupation
EC
ya the manufacture of wire that profit from you buying more are telling you to buy more.
Follow the money.
Nmb has been fine in my coastal rainforest area for 60 years. I won’t do it for liability but it’s a joke.
 

JohnE

Senior Member
Location
Milford, MA
If we all agree that NM cable in an outdoor conduit is a wet location and prohibited, do we have a concrete argument that it is dangerous? We probably all agree that it is not thwn or any "w" rated insulation, but the only argument I see is that it isn't rated. I agree completely. I don't advocate that it is. But is there an argument that it is "unsafe", aside from the argument that if it isn't rated, it must be unsafe? We've heard anecdotally that it is "the same" insulation as the thhn/ thwn product within the cable. No argument at all that it is flat out illegal. Where is the 'danger'? I also realize that as this is a professional forum, we can't advocate any non-compliant installation. Just asking for real world advisories.
 
If we all agree that NM cable in an outdoor conduit is a wet location and prohibited, do we have a concrete argument that it is dangerous? We probably all agree that it is not thwn or any "w" rated insulation, but the only argument I see is that it isn't rated. I agree completely. I don't advocate that it is. But is there an argument that it is "unsafe", aside from the argument that if it isn't rated, it must be unsafe? We've heard anecdotally that it is "the same" insulation as the thhn/ thwn product within the cable. No argument at all that it is flat out illegal. Where is the 'danger'? I also realize that as this is a professional forum, we can't advocate any non-compliant installation. Just asking for real world advisories.

I guess I dont know enough about plastic chemistry to answer. Why is THHN (only) not ok to be wet? What happens? its still "waterproof" isnt it? IS there something about it where it looses dielectric or physical strength when wet and/or hot?
 

jap

Senior Member
Occupation
Electrician
If we all agree that NM cable in an outdoor conduit is a wet location and prohibited, do we have a concrete argument that it is dangerous? We probably all agree that it is not thwn or any "w" rated insulation, but the only argument I see is that it isn't rated. I agree completely. I don't advocate that it is. But is there an argument that it is "unsafe", aside from the argument that if it isn't rated, it must be unsafe? We've heard anecdotally that it is "the same" insulation as the thhn/ thwn product within the cable. No argument at all that it is flat out illegal. Where is the 'danger'? I also realize that as this is a professional forum, we can't advocate any non-compliant installation. Just asking for real world advisories.

I think it all boils down to trying to maintain the integrity of the cable as a whole, not so much as it being unsafe.

In UF there is not paper inside of it like there is in NM, and, we all know the paper does in fact fall apart inside the cable after it's been wet for a time although the conductors themselves may not be affected.

We don't install Nema 1 enclosures outdoors either although with adequate drainage they'd probably hold up just about as well truth be known.

JMHO,

Jap>
 
Top