Romex in a Conduit

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glene77is said:
Jumper,

This is a DIY. Don't even look at his EGC connection, thanks.

Protection is a good idea.
Running from a panel to a dedicated receptical, surface mounted in a garage, imagine that the Romex leaves the panel, up an inclosed wall, across the attic, entered conduit in the garage, down the wall to the Receptical.

I have been told I must transition from Romex, in a JB, and down with THHN.
I maintain that the code allows a continuous run of Romex
from the Breaker Box to the conduit and down to the Receptical.
Click to expand...

and i maintain that you are right, np jb is necessary, 334.15c bushing or connector only .
 
glene77is said:
Can Romex EVER be run inside of a conduit?

The attached photo is a 'leading' example,
to intice comments.
Click to expand...

Yes, it is allowed in all the 3xx.22 article sections.

Using EMT for an example

358.22 Number of Conductors.
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9.

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.
Click to expand...

There is nothing in article 334 prohibiting NM from being installed in conduit.

Roger
 
Alwon,
Thank you for your response.

Can Romex EVER be run inside of a conduit?
Refering to a code correct project,
Can I run Romex from a Breaker Panel,
up inside a covered wall,
across an attic,
enter a EMT in the attic,
pass right down an exposed wall to a Recepital?

I have been told that I must make a transistion.
(1) NM up and across the attic,
(2) enter a JB, and connect to THHN,
(3) down the EMT on the wall surface to the receptical.

I say that I don't have to make any transition, just run Romex all the way,
and into the EMT and on down to the Receptical.
I say "No JB, and No THHN".

I have been told that I must make the transition from NM to THHN
before entering the conduit down to the receptical.

What does the code say about not running NM inside a conduit
in this kind of application?
 
Here is an illustration that seems to apply.

1100551339_2.jpg


Roger
 

Gus,
Thanks.
I see your good points, and thanks for a code reference.

I need to run from a Panel, up a covered wall, across an attic,
then enter EMT to go down a surface mounted receptical.
I have been told that I must transition from NM, in a JB, to THHN,
then through the EMT down the surface of the wall to the receptical.

IMO, I think that the code allows NM all the way, in one peice;
that is, no transition to THHN at the conduit run down the wall.

Of course, when the master says do it, I do it his way first.
I still have these lingering questions, just a personality trait of mine.
 
I would say as long as your raceway system is complete from one end to the other and you comply with Note 9 of Table 1, Chapter 9 concerning dimensions (often overlooked), there is no violation.
If the raceway is not complete, the references I gave earlier.
 
Last edited:
Roger,

Thank you, 334.30.
The application is right on target with mine.

Mike does have a good artist on staff.
His drawings combine several concepts at one time,
making them more vivid and memorable.

So, I'll still wire it the way I was told.
And my question stands answered.
I can live with that.
 
On the "cabinet" end, I would think 312.(5)(C) would prohibit an installation such as shown IF the conduit penetrated a structural ceiling.
 
Roger,
Thanks.
Now that's settled in my mind,
I'll go to work Monday and try to do a good job.

I did notice, in 334..., that there is no mention of NM-B,
only NM-C (corrosion) and NM-S (signal).
I am sure that NM and NM-B are the same, just a tradename conflict or something.
I understand from reading that "B" stands for the higher temperature version
of the old NM cable, from 60 to 90 degrees C, from TW to THHN.

On that note, I do not find any stamped info on the wire internal to the NM cable.
I guess that means that we cannot strip the yellow plastic off the NM
and then reuse the wire inside the sheath, as in making joints.
It looks like THHN and has the same apparent thinness of insulation,
and the same temp rating.
 
glene77is said:
On that note, I do not find any stamped info on the wire internal to the NM cable.
I guess that means that we cannot strip the yellow plastic off the NM
and then reuse the wire inside the sheath, as in making joints. .
Click to expand...


Where is the permission to strip off the labeling to enter a panel?
 
augie47 said:
On the "cabinet" end, I would think 312.(5)(C) would prohibit an installation such as shown IF the conduit penetrated a structural ceiling.
Click to expand...

Gus,
Thanks, I will check on that idea.
312. (5)(C). I will give it a check.
Locally we are allowed something that is similar.
Needs to be checked on, and against the NEC.
 
"NM" disappeared with the manufacturer of NM-B ( 90? )
NM conductors are "insulated" but do not necessarily meet the specs of THHN and can not be substituted for a THHN application.
 
augie47 said:
On the "cabinet" end, I would think 312.(5)(C) would prohibit an installation such as shown IF the conduit penetrated a structural ceiling.
Click to expand...

Now that is a another violation that I see all over the place. @' PVC stubbed up to an attic and bunches of nm cable pushed down the pipe and the conduit wide open. Same going into a crawl space.

I have seen 2" PVC pipe connectors used with all the homeruns run thru it.
 
iwire said:
Where is the permission to strip off the labeling to enter a panel?
Click to expand...

Iwire,

Well, what I referred to is the habit of grabbing scrap wire and making joints,
pigtails, etc. In the last residential job, we grabbed some scrap Romex, stripped off the sheathing.
This was to help making pigtails.
I question "where is the permission?" also.
Usually, we do industrial and have spools of THHN, MTW,
etc. around, for joint making.
It is just something we do,
and the question just passed by my mind, also.
I never thought much about it.

There is a code section that requires a 1/2 inch of sheathing
as Romex enters into a panel.
That makes sense for the protection of the wire.
The remainder of the cable sheathing (inside the panel)
is always stripped off (including the 'labeling')
so that the wires can be landed.

I hope I caught your thought.
 
My thought is this.

Many people say that if we install cables in raceways we must leave the labeling on the cable that is required by 310.11.

OK, then where is the section of the NEC that allows me to remove 3 or 4 feet of that labeling at the panel?
 
Dennis Alwon said:
Now that is a another violation that I see all over the place. @' PVC stubbed up to an attic and bunches of nm cable pushed down the pipe and the conduit wide open. Same going into a crawl space.

I have seen 2" PVC pipe connectors used with all the homeruns run thru it.
Click to expand...

Amen! I had an out-of-area contractor start to do a chain motel that way. Said this was his 50th some odd and no one had turned him down yet. (you're not in Kansas any longer, Toto)
 
Dennis Alwon said:
Now that is a another violation that I see all over the place. @' PVC stubbed up to an attic and bunches of nm cable pushed down the pipe and the conduit wide open. Same going into a crawl space.
I have seen 2" PVC pipe connectors used with all the homeruns run thru it.
Click to expand...

Alwon,

You are right. I see it too, on the few residential jobs we work on.

I know that locally we are allowed this general technique,
but not into floorable areas.
Only with bushings, and only with a limited number of cables.
Red Standoff Trees are good to handle head dissipation.

This makes me wonder just how many cables
I can run through a 5/8 inch hole in a wall plate.
My helper says there is NO UL listing on the holes, just 'pack em',
but I only put one cable through,
unless it's old work and there is a genuine problem making more holes.
 
iwire said:
My thought is this.

Many people say that if we install cables in raceways we must leave the labeling on the cable that is required by 310.11.

OK, then where is the section of the NEC that allows me to remove 3 or 4 feet of that labeling at the panel?
Click to expand...

Iwire,

By the letter of the code, I would say that there should be enough
of the original sheathing to identify the cable, before any stripping occurs.

On the other hand, only a "qualified person" (Art.100) (electricians) are supposed to ever be in the panel, and we know what we are working with.
Of course, there are surprises.

I always keep my left hand in my pocket when I am around a panel, and that attitude of safe lookout has helped keep me alive for 40 years of this.
That makes me at least somewhat "qualified", ha.
There is always something more to learn,
that makes the work great,
and I hope it lasts a few more years.
 
augie47 said:
"NM" disappeared with the manufacturer of NM-B ( 90? )
NM conductors are "insulated"
but do not necessarily meet the specs of THHN
and can not be substituted for a THHN application.
Click to expand...

Gus,
I think I agree.
I was looking in the '05 code handbook, and did not see a "NM-B" reference where I expected it. Umm.

I understand the 'Not Necessarily' comment. Good point.

I doubt that the practice of using stripped NM for joint making
places one's work on the edge of disaster,
but it is good to think about it.
 
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