Romex in conduit...sort of?

[sfav8r]

I was at a call yesterday, which I must go to again today. I ran across something I've never seen and while I can't think of a code reference off the top of my head, it just looks wrong.

Basically, their is NMC running from branch circuits back to the panel. Where the NMC drops from the floor joists down the wall to the panel, it is covered as it should be.

The service panel is on the exterior. There is an 1-1/4 IMC stub that goes from the back of the panel, through the exterior siding. This is where the NMC enters the panel. The sheathing was stripped off of the NMC at the other end (inside the basement) and enters the panel as seperate wires.

There are proper bushings etc. and I must admit the job looks clean, but I've nver seen NMC that "turns into" individual wires.

Is this OK? If I was doing the original installation, I would put a junction box in the basement, run all the NMC to the junction box, then run THHN from the junction box to the panel. But then again that is a bunch more connections that may not be necessary.

I was there to add several new circuits and if the existing setup is not to code, I want to rectify that before I add new circuits.

Thanks!

 

[tom baker]

Re: Romex in conduit...sort of?

NO this is not allowed. Each NM cable must be secured with a clamp where it enters the box.

 

[bphgravity]

Re: Romex in conduit...sort of?

Even though a code violation or two could be cited for this installation, I really don't see a clear hazard that exists or could develope from this method. I would consult the AHJ and let them determine compliance and/or needed correction.

 

[rbalex]

Re: Romex in conduit...sort of?

334.112 Insulation. The insulated power conductors shall be one of the types listed in Table 310.13 that is suitable for branch circuit wiring or one that is identified for use in these cables. Conductor insulation shall be rated at 90?C (194?F).
FPN: Types NM, NMC, and NMS cable identified by the markings NM-B, NMC-B, and NMS-B meet this requirement.

I wish the FPN were clearer because all NM, NMC and NMS that aren't signaling cables (see 334.104) "...meet this requirement."
"-B" is all that's manufactured today.

The problem is that some conductors are only "identified for use in these cables" and may not be mechanically suitable for installation in raceways.

In my opinion, where they are identified as "regular" 90?C conductors, they should be permitted as described, especially in light of the fact that the ampacity restrictions of 334.80 are still in effect. The fewer splices and terminations the better.

[ July 06, 2004, 12:11 PM: Message edited by: rbalex ]

 

[electricman2]

Re: Romex in conduit...sort of?

Where I work, we are allowed to run 2 or more NM cables into the back of an exterior mounted panel through a short length of conduit. The cable must be secured just before entering conduit and sheath must extend into panel at least 1 inch or more.

 

[hbiss]

Re: Romex in conduit...sort of?

rbalex, I don't know how what you are talking about applies to the original question...

Section 312.5(C) allows this IF (among other things) the conduit is between 18 inches and 10 feet in length and enters a surface mounted enclosure on its top.

As electricman2 points out, what you have seen may be a local amendment to this.

-Hal

 

[rbalex]

Re: Romex in conduit...sort of?

sfav8r's original description didn't comply with 312.5(C) Exception in several instances.

My point was that what he did describe should not be a problem, especially if the individual conductors were Table 310.13, 90?C compliant.

Most manufactures that make both NM and standard building wire use the building wire to make the NM. A few manufactures that only make NM use conductors "...identified for use in these cables." Those conductors may or may not be "...suitable for branch circuit wiring ..." and therefore may or may not be suitable for installation in a raceway without the sheath - as sfav8r described it.