Listing for conductors

[SparkyHC]

During a seminar last week a comment was made regarding Romex installed in emt conduit...
If the Romex is pushed through a length of conduit into a metal outlet box which the conduit is connected to, it will
not be restrained by a listed Romex connecter so this would be a violation...
The comment then followed that, OK - I'll put an EMT connecter with a rigid coupling and Romex connector on the end of
the EMT and then strip the Romex and push it through the conduit...
Now this is where the question here begins...It was suggested that stripping the outer jacket of the Romex to feed just
the conductors through the conduit would also be a violation as "the conductors are only "listed" with the non-metallic sheath."
If this is correct, where is this "listing" in writing?

 

[GoldDigger]

During a seminar last week a comment was made regarding Romex installed in emt conduit...
If the Romex is pushed through a length of conduit into a metal outlet box which the conduit is connected to, it will
not be restrained by a listed Romex connecter so this would be a violation...
The comment then followed that, OK - I'll put an EMT connecter with a rigid coupling and Romex connector on the end of
the EMT and then strip the Romex and push it through the conduit...
Now this is where the question here begins...It was suggested that stripping the outer jacket of the Romex to feed just
the conductors through the conduit would also be a violation as "the conductors are only "listed" with the non-metallic sheath."
If this is correct, where is this "listing" in writing?

Although the conductors clearly have to be stripped after the approved clamp in order to be terminated, a different issue comes up if the unsheathed conductors are going to be run any distance, such as in raceway under the listing of the individual conductors. The biggest concern I have seen here is whether the isolated conductors are in fact properly labelled as to size and insulation type once the sheath has been stripped off.

If those labeling requirements are met, then probably OK. There may be some brands of NM (although probably not Romex (TM)) which do not use individually labeled inner conductors.

 

[iwire]

I will just point out that the NEC specifically allows cables in raceways via xxx.22 of each raceway article.

 

[Smart $]

...
Now this is where the question here begins...It was suggested that stripping the outer jacket of the Romex to feed just
the conductors through the conduit would also be a violation as "the conductors are only "listed" with the non-metallic sheath."
If this is correct, where is this "listing" in writing?

What you were told is actually a twist on the matter, which has nothing to do with the listing. The actual violation is that the stripped conductors in a raceway are not an NEC recognized wiring method. Conductors run in raceway must be of a type in Table 310.104(A).

 

[iwire]

If those labeling requirements are met, then probably OK. There may be some brands of NM (although probably not Romex (TM)) which do not use individually labeled inner conductors.

I understand my view is a minority one but in my opinion the labeling requirements are only manufacturing requirements not an installation requirement.

If that is not the case we have a violation every time we strip the sheath of NM to enter it into a panelboard cabinet.

 

[GoldDigger]

What you were told is actually a twist on the matter, which has nothing to do with the listing. The actual violation is that the stripped conductors in a raceway are not an NEC recognized wiring method. Conductors run in raceway must be of a type in Table 310.104(A).

And if the conductors inside the sheath are in fact lableled (and therefore listed?), such as THWN, then they are type 310.104(A) conductors.
I do not see NM as a wire or cable type in that table, but it seems to be generally agreed that you can run intact NM inside a raceway.

 

[Smart $]

And if the conductors inside the sheath are in fact lableled (and therefore listed?), such as THWN, then they are type 310.104(A) conductors.

Yes... but I've not seen any such labeled conductors in NM.

I do not see NM as a wire or cable type in that table, but it seems to be generally agreed that you can run intact NM inside a raceway.

But that's mostly where the raceway serves a purpose other than than a raceway, such as support or physical protection. There are only a couple sections which allow NM in a conduit terminating to an enclosure or box.

 

[GoldDigger]

Yes... but I've not seen any such labeled conductors in NM.

I have not either, but I have seen reports of such by members, although not with manufacturer and part number.

I think we are really talking about the same thing and basically agree: Regardless of the formulation and thickness of the insulation, a conductor is not of a particular type unless it is listed, and as part of the listing it has to be marked.
If it is not marked it cannot not be not listed, and if it is not listed it cannot be an approved wiring type under 310.
The incidental exposure of the inner conductors as part of the termination process, in a box rather than in conduit, etc., does not seem to be a problem. There would be a workmanship issue if the inner conductors wander two or three times around the inner perimiter of a panel, but probably not a clear violation.

 

[Smart $]

...
The incidental exposure of the inner conductors as part of the termination process, in a box rather than in conduit, etc., does not seem to be a problem. There would be a workmanship issue if the inner conductors wander two or three times around the inner perimiter of a panel, but probably not a clear violation.

My perspective is the degree of protection and safety provided by the sheath versus in raceway. The raceway clearly exceeds that of the sheath for physical protection, but from the standpoint of insulation properties the sheath exceeds that of a metallic raceway. One may contest that the raceway is grounded whereas the sheath is not, and another discussion ensues...

 

[GoldDigger]

...but from the standpoint of insulation properties the sheath exceeds that of a metallic raceway.

Which is why we would need to know the detailed insulation properties of the individual conductors to be able to evaluate the bare conductor use.
But the metallic raceway does nothing to diminish the insulation properties of the intact sheath.
Might be a little hard to pull, although you can get NM with a Simpull (TM) sheath.
Definitely increases the fill percentage, and
probably justifies a greater ampacity adjustment.
The list goes on.

 

[Smart $]

Which is why we would need to know the detailed insulation properties of the individual conductors to be able to evaluate the bare conductor use.

I believe you meant unsheathed...

But the metallic raceway does nothing to diminish the insulation properties of the intact sheath.

That's correct. And where permitted to run in conduit connected at one end, the sheath must remain intact through the conduit and secured near the entry.

 

[Dennis Alwon]

During a seminar last week a comment was made regarding Romex installed in emt conduit...
If the Romex is pushed through a length of conduit into a metal outlet box which the conduit is connected to, it will
not be restrained by a listed Romex connecter so this would be a violation...

I disagree as art. 334.15(C) allows this.

334.15(C) In Unfinished Basements and Crawl Spaces. Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables
shall be run either through bored holes in joists or on running boards. Nonmetallic-sheathed cable installed on the wall of an unfinished basement shall be permitted to be installed in a listed conduit or tubing or shall be protected in accordance with 300.4. Conduit or tubing shall be provided with a suitable insulating bushing or adapter at the point the cable enters the raceway. The sheath of the nonmetallic-sheathed cable shall extend through the conduit or tubing and into the outlet or device box not less than 6 mm (1?4 in.). The cable shall be secured within 300 mm (12 in.) of the point where the cable enters the conduit or tubing. Metal conduit, tubing, and metal outlet boxes shall be connected to an equipment grounding conductor complying with the provisions of 250.86 and 250.148.

This article also states that you cannot strip the nm inside the conduit as the jacket must stick the box.

 

[don_resqcapt19]

I disagree as art. 334.15(C) allows this.

334.15(C) In Unfinished Basements and Crawl Spaces. Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables
shall be run either through bored holes in joists or on running boards. Nonmetallic-sheathed cable installed on the wall of an unfinished basement shall be permitted to be installed in a listed conduit or tubing or shall be protected in accordance with 300.4. Conduit or tubing shall be provided with a suitable insulating bushing or adapter at the point the cable enters the raceway. The sheath of the nonmetallic-sheathed cable shall extend through the conduit or tubing and into the outlet or device box not less than 6 mm (1?4 in.). The cable shall be secured within 300 mm (12 in.) of the point where the cable enters the conduit or tubing. Metal conduit, tubing, and metal outlet boxes shall be connected to an equipment grounding conductor complying with the provisions of 250.86 and 250.148.

This article also states that you cannot strip the nm inside the conduit as the jacket must stick the box.

Interesting that this provision only applies on the wall of an unfinished basement.

 

[Dennis Alwon]

Interesting that this provision only applies on the wall of an unfinished basement.

I think this is one of those rules where it was meant as an example. It would make no sense otherwise. I have never seen an inspector who would only allow that type of install in a basement

 

[kwired]

I have never seen a conductor type marking on conductors of NM cable that I am aware of. I have seen marking on conductors of some AC/MC cables before.

 

[roger]

I have never seen a conductor type marking on conductors of NM cable that I am aware of. I have seen marking on conductors of some AC/MC cables before.

They are not identified in NM.

As far as the OP's question, if I understand correctly the illustration below is applicable. (from the 2005)

Roger

 

[kwired]

They are not identified in NM.

As far as the OP's question, if I understand correctly the illustration below is applicable. (from the 2005)

Roger

some people will interpret the end of that "protective sleeve" to be the equivalent of a box cabinet or fitting and require securing it within 12 inches per 334.30. I do find error in that drawing by calling it a raceway when it should be called a "protective sleeve" or something similar. It may be made out of something that is listed as a raceway but it is not used in accordance to raceway articles in this case. 300.18(A) tells us that raceways "shall be installed complete between outlet, junction, or splicing points prior to the installation of conductors".

 

[roger]

some people will interpret the end of that "protective sleeve" to be the equivalent of a box cabinet or fitting and require securing it within 12 inches per 334.30. I do find error in that drawing by calling it a raceway when it should be called a "protective sleeve" or something similar. It may be made out of something that is listed as a raceway but it is not used in accordance to raceway articles in this case. 300.18(A) tells us that raceways "shall be installed complete between outlet, junction, or splicing points prior to the installation of conductors".

334.30 is specific to NM, we don't have to worry about 300.18, read the last sentence of 334.30 for clarification.
As an aside, the definition of raceway doesn't include the word complete.

Roger

 

[kwired]

334.30 is specific to NM, we don't have to worry about 300.18, read the last sentence of 334.30 for clarification.
As an aside, the definition of raceway doesn't include the word complete.

Roger

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

All that tells me is I don't have to secure the cable within the raceway, and tells me nothing about installing the raceway itself, or what to do at the raceway to cable transition point.

 

[Smart $]

... I do find error in that drawing by calling it a raceway when it should be called a "protective sleeve" or something similar. It may be made out of something that is listed as a raceway but it is not used in accordance to raceway articles in this case. 300.18(A) tells us that raceways "shall be installed complete between outlet, junction, or splicing points prior to the installation of conductors".

A raceway terminated at only one end to electrical equipment is still a raceway. Cables, including single conductor cable, and cords can be used with this wiring method, but single conductors cannot. The entry and securing requirements vary by type of cable/cord.