Romex and 1/2" conduit

Reply

  #1  
Old 06-04-08, 12:10 AM
H
Member
Thread Starter
Join Date: Mar 2008
Posts: 10
Received 0 Votes on 0 Posts
Exclamation Romex and 1/2" conduit

Let me preface this by saying I'm not an electrician and, as my username states, I'm new to home-ownership. I've got some electrical experience with changing outlets and adding new circuits to the box but nothing totally advanced... the typical "city-boy" doing the work due myself, not having the money to hire a professional.


Here's my situation. I recently bought 14/2 G indoor Romex for an indoor project. Now, what I want to do is add a 2-bulb flood light and a 15a GFCI outlet outside. These two new electrical items will be protected from direct snow and rain by a "roof", under which I keep my pool accessories, my BBQ, and a few other items. This area basically looks like, if you were to imagine, an awning connected to the house... no walls, just a roof. But it's a real roof, made with 2x4s, plywood and roofing shingles.

I want to make this add look clean, so I bought 20 feet of 1/2" ENT conduit, with a coupler and a 90 degree pull-thru elbow, and a wet-location box for the flood light and one for the GFCI.

My questions are: 1. Can I use this conduit outside, under this roof, if I seal all the possible openings to the weather/moisture? 2. I understand that you cannot use indoor romex in outdoor conduit, due to moisture that can build-up in the paper around the wires, BUT, can I use the romex in the conduit, IF I STRIP the plastic romex jacket off and remove all the paper wrapping, essentially making it like single strand THWN? Again, I'm trying to save money by using what I have at hand, but of course, I don't want to do something that can start a fire. Can anyone send some answers my way? Thank you!
 
  #2  
Old 06-04-08, 12:35 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,581
Received 13 Votes on 11 Posts
No. The wire in the Romex is not rated as THHN or THWN.
 
  #3  
Old 06-04-08, 04:33 AM
chandler's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Dec 2005
Location: USA
Posts: 39,964
Received 6 Votes on 6 Posts
Although it is not recommended, and is a PITA, you can run the NM-UF in conduit as a cable, but why? It is too easy to just buy THHN or THWN in colors, run it in the conduit and be done with it. You will find it much easier if you do it that way.
 
  #4  
Old 06-04-08, 09:51 AM
J
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
There is no prohibition against using NM-B outdoors. The only requirement is that the location be "dry". Moisture buildup inside conduit is usually only a problem if the conduit is underground or exposed to the elements.

But I would never, ever try to pull NM-B cable through 1/2" conduit, especially if it had a bend. Depending on the gauge of the wire, even a single NM-B could violate conduit fill limits of 1/2" conduit. And you should never, ever strip the individual wires out of cable--it's not only a code violation, but it's very difficult to do and the chances that you'll damage the insulation are high.
 
  #5  
Old 06-04-08, 10:13 AM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,713
Received 54 Votes on 51 Posts
Originally Posted by Homeowner_2_B View Post
I want to make this add look clean, so I bought 20 feet of 1/2" ENT conduit,
I've used ENT (the blue flex stuff, correct?); and, it's not what I'd call clean for a visible location. There are just so many limitations with it: Not sunlight rated (it rots with UV), it's not rated for exposed protection of conductors, it's hard to paint (thin grooves), you need a ton of clamps to make it even to start to look straight. Can you use emt or rigid plastic conduit instead? If your working around bends in a small space, then maybe liquidtite?
 
  #6  
Old 06-05-08, 10:35 PM
H
Member
Thread Starter
Join Date: Mar 2008
Posts: 10
Received 0 Votes on 0 Posts
Thumbs up

Thanks for all your replies... to make it simple and to avoid any problems, "Chandler", I probably will just go out and buy the THWN, but since I had extra indoor romex left, just wanted to know if I could use it and save a little money.

"Telecom guy", the ENT conduit I have is a 1/2" round aluminum tube- the stuff you would normally find on a stage or connecting fire pull stations... not the blue stuff.

"John Nelson" thanks for the info on the "dry" location. I actually HAD stripped the individual wires out of the romex jacket, using a utility knife, being careful to cut down the center, where the paper-coated ground was... HOWEVER, since that day I have not continued any work, just because I wasn't certain if it would be legal or not...

"ray2047", I've been to the hardware store and THWN/THHN looks similar to the wires inside romex, so I wasn't sure if it was the same thing..

Thank you all for clearing up my questions.. I'm sure I'll have more later, but this is a good start.. Thanks again!
 
  #7  
Old 06-05-08, 10:52 PM
F
Member
Join Date: Mar 2006
Location: NE Wis / Paris France{ In France for now }
Posts: 4,807
Received 0 Votes on 0 Posts
As far you can see why with romex wire if you take the outer coating off and you see the wires unmarked that the moot point if it is not marked then we can not use them in the conduit.

The code is pretty specfic on this one.

Merci,Marc
 
  #8  
Old 06-06-08, 04:04 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 13,937
Received 293 Votes on 255 Posts
ENT = Electrical Nonmetallic Tubing: Sometimes called smurf pipe, it is plastic, flexable, blue or gray.

You are talking about:

FMC = Flexible Metal Conduit (or FMT = Flexible Metallic Tubing)
 
  #9  
Old 06-06-08, 04:59 PM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,713
Received 54 Votes on 51 Posts
I think he has EMT

And, it's very likely NOT Aluminum. As the little rust dots on the patio will testify to (a couple days after the hacksawing)
 
  #10  
Old 06-09-08, 02:23 AM
H
Member
Thread Starter
Join Date: Mar 2008
Posts: 10
Received 0 Votes on 0 Posts
Smile

Okay.. I guess it's not ENT, by that definition, but the metal couplers and elbows I got at Home Depot were in the boxes with the blue labels marked ENT, so I assumed the conduit was ENT as well. As for thinking the conduit was aluminum, I cut it to length, using a plumbing pipe cutter and it was easy to cut thru.. figured it was a soft aluminum.


This is why I'm glad I posted my questions. This is all great information. Thank you to everyone!
 
  #11  
Old 06-09-08, 05:08 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 15,250
Received 112 Votes on 97 Posts
Plumbing type tubing cutters should not be used to cut metallic conduits. They will leave a sharp ridge that can cut through the insulation.

Even using the proper tools the edge needs to be reamed to remove any sharp burrs.
 
  #12  
Old 06-12-08, 01:22 AM
H
Member
Thread Starter
Join Date: Mar 2008
Posts: 10
Received 0 Votes on 0 Posts
I realized that after I had done it.. I only had one cut, so I worked on it for a while and finally got it down to where I could run my finger around the edge and not get cut. Again, trying to go the cheaper route, I opted for a plumbing pipe cutter which I already had, as opposed to a pipe bender for $32.00. In the future I'd probably go with a pipe bender, just to save on the time it takes to clean the cut edge.

Originally Posted by pcboss View Post
Plumbing type tubing cutters should not be used to cut metallic conduits. They will leave a sharp ridge that can cut through the insulation.

Even using the proper tools the edge needs to be reamed to remove any sharp burrs.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: