Underground conduit: NM vs. THWN

[pdel]

What is the section, if any, of 2004 California/2002 NEC that prohibits NM cable in underground rigid conduit (P40 PVC) and/or requires individual THWN?

 

[raider1]

Take a look at 334.12(A)(10)(d) 2002 NEC

Chris

 

[Pierre C Belarge]

Take a look at 334.10(A)(1)
& 300.5(B)

 

[haskindm]

Look at the sections that they referenced. You also need to keep in mind that an underground conduit of any type is considered a wet location. Is NM suitable for a wet location?

 

[goldstar]

Just a few side bar questions while we're on this subject :

Is it acceptable to strip off the jacket of the NMC and paper wrapping around the EGC and use these conductors for something like an AC fixture whip ? I believe the insulated conductors in NMC are THHN. Am I wrong ?

Is it required for the EGC inside PVC to be insulated ?

The whip obviously isn't buried so, is the inside of the whip considered a wet or damp location ?

 

[raider1]

Is it acceptable to strip off the jacket of the NMC and paper wrapping around the EGC and use these conductors for something like an AC fixture whip ? I believe the insulated conductors in NMC are THHN. Am I wrong ?

This is a violation of 310.11, which requires that conductors be marked.

Is it required for the EGC inside PVC to be insulated ?

No.

The whip obviously isn't buried so, is the inside of the whip considered a wet or damp location ?

The inside of a conduit in not a seperate location. The area where the conduit is located is the determining factor. So if the whip is in a wet location the inside of the whip is also in a wet location.

Chris

 

[petersonra]

Just a few side bar questions while we're on this subject :

Is it acceptable to strip off the jacket of the NMC and paper wrapping around the EGC and use these conductors for something like an AC fixture whip ? I believe the insulated conductors in NMC are THHN. Am I wrong ?

They may have THHN insulation but are not marked AFAIK.

Any reason you can't just run the NM as is in the whip?