Inspected a job where the manufacturer built walls in the factory and installed non metallic boxes and smurf tubing inside the walls and styrafoam (spelling) insulation. Walls are sealed up and now he wants the electrical contractor to pull in NM cable for the wiring method. My understanding is that this would violate the code. NM cable is not Listed for use in ENT. I believe the contractor should be using single conductors. What does this forum think?

NM is not approved for installation as you have described only for the reason that a approved cable connector will not be used at the point where it enters the box.

Code violation...yes.

Hazard to people and property...no.

shortcircuit

In addition to support issues described by sc, the width of the NM cable would have to be considered in order to satisfy raceway fill, per "Notes to Tables" in Chapter 9.
What size tubing? What size NM?
In my opinion, it seems amateurish to attampt to install romex in raceways.
Single conductors is the proper way to go.

[This message has been edited by Redsy (edited 03-12-2005).]

The 2005 clears this up and it is allowed. It was never really the intent that NM was not allowed in raceways, but I won't dwell there.

Article 362.22 (all the xxx.22 sections are the same)

Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.

Roger

Depends on the runs. I'm going to assume that they are stubbed up into the ceiling space at the top. I think the main issue is going to be the transition from NM to the tubing with the connector requiremment. I don't believe that you can put an adaptor and NM connector on the end of the tubing because it needs to be accessable. This would mean extending the tubing to an accessable J box. This would also mean that there would be no reason to pull NM but rather single conductors as necessary.

-Hal

I agree with Roger as to intent.
After all, adapter fittings to connect NM to EMT have been around for a long time. But, the issue has been debated several times, with the "securing the cable" argument probably being the most compelling reason not to do it.

I do not see the problem with romex in a raceway if the raceway is appropatly sized.

Last sentence of 334.30 2005 code
" Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway."

If the romex is in a raceway and the raceway terminates correctly in a box, why not use it.

While I personally would probably use an acessable J box in an attic or unfinished basement and THHN, it appears to be nothing wrong code wise with using romex this way.

[This message has been edited by nesparky (edited 03-12-2005).]