Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-17-2011, 03:03 AM   #1
Newbie
 
Join Date: Jan 2010
Location: Honolulu
Posts: 17
Rewards Points: 10
Default

NM Romex in conduit for detached garage??


Hi. Im running a subpanel to a detached garage. It will be a long 100ft run at 30a 220v. Im planning on using 6/3 romex.

From the main house breaker panel, it will traven through the attic, down the exterior side of the house, underground into the sidewalk/concrete slab, up an exterior brick wall, and into the detached garage. The exterior portions will be covered by 1" PVC conduit.

My question is...

Is it ok to use 6/3 romex wire inside of the pvc conduit? Do i need to use UF, or THHN, or is standard NM ok?

Thanks in advance!

ericht is offline   Reply With Quote
Old 10-17-2011, 04:27 AM   #2
Semi-Pro Electro-Geek
 
Join Date: Jul 2009
Location: Arizona, USA
Posts: 2,559
Rewards Points: 2,014
Default

NM Romex in conduit for detached garage??


NM is not rated for wet locations, which precludes its use outdoors, in conduit or otherwise. It gets run in underground conduits all the time by people who don't know this, and it fails as a result. The insulation does not do well in constant contact with moisture. Use THWN/THHN.

mpoulton is offline   Reply With Quote
The Following 2 Users Say Thank You to mpoulton For This Useful Post:
Code05 (10-17-2011), ericht (10-17-2011)
Old 10-17-2011, 05:05 AM   #3
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 4,173
Rewards Points: 2,256
Default

NM Romex in conduit for detached garage??


If you only need 30 amps, you can save some money and use #10 IHWN instead of #6.
__________________
Location:
Coastal South Carolina
rjniles is online now   Reply With Quote
The Following 2 Users Say Thank You to rjniles For This Useful Post:
Code05 (10-17-2011), ericht (10-17-2011)
Old 10-17-2011, 06:20 AM   #4
Newbie
 
Join Date: Jan 2010
Location: Honolulu
Posts: 17
Rewards Points: 10
Default

NM Romex in conduit for detached garage??


Thanks guys.

So is UF ok to run in coduit?
I only ask because i have "heard" that only individual wires can be ran in conduit, and that cable insulation may cause the wires to overheat. Also, i know it will be a PITA to pull through, but im fine with that.

And im using 6ga wire because of the long run, and to leave room for expansion.
ericht is offline   Reply With Quote
Old 10-17-2011, 06:21 AM   #5
Newbie
 
Join Date: Jan 2010
Location: Honolulu
Posts: 17
Rewards Points: 10
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by rjniles View Post
If you only need 30 amps, you can save some money and use #10 IHWN instead of #6.

Btw.. what is IHWN..?? I've never seen it locally
ericht is offline   Reply With Quote
Old 10-17-2011, 07:51 AM   #6
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,824
Rewards Points: 2,446
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by ericht View Post
Btw.. what is IHWN..?? I've never seen it locally
That should be THWN. It is individual conductors.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now   Reply With Quote
Old 10-17-2011, 09:29 AM   #7
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,340
Rewards Points: 2,342
Default

NM Romex in conduit for detached garage??


Is this a home on slab, or does it have a crawl or basement?

Mpoulton, if that was the case, hundreds of thousands of homes with basements and garages would not have NM in those two spaces.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 10-17-2011, 09:41 AM   #8
JOATMON
 
ddawg16's Avatar
 
Join Date: Aug 2011
Location: S. California
Posts: 7,578
Rewards Points: 2,486
Default

NM Romex in conduit for detached garage??


Use #6 THHN/THWN....2 black wires, 1 white wire. Your ground can be a #8 (or 10 I think). In 1", easy to pull. That is exactly what I did to my detached garage. It used to be 3/4"...fit, but was a b!tch to get through.

Even though you think the PVC pipe keeps the wires dry...water still gets in. There are a lot of factors dictating what can and can't be in conduit. There have been a lot of discussions on this board and others about Romex in conduit. I don't think the NEC forbids it....but my county does not allow it. My inspector said that it's not allowed here because of the heat rise. Even though you may be ok space on wire fill, the Romex cover keeps the heat in. Good chance you could exceed the heat rise.

I am personally a big fan of THHN....easy to pull....easy to terminate....

BTW....make sure you don't bond the earth to your neutral in your garage sub panel. And you might want to check...but you will most likley need a ground rod at the garage.
__________________
Even if you are on the right track, you will still get run over if you just sit there.

My 2-Story Addition Build in Progress Link ... My Garage Build Link and My Jeep Build Link
ddawg16 is offline   Reply With Quote
The Following User Says Thank You to ddawg16 For This Useful Post:
ericht (10-19-2011)
Old 10-17-2011, 11:07 AM   #9
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 4,173
Rewards Points: 2,256
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by ericht View Post
Btw.. what is IHWN..?? I've never seen it locally
Typo, meant THWN.

OP, 100' is not a long run so voltage drop is not a real concern. I would run THWN in conduit(first choice) or direct bury UF. I would not run UF in conduit, a real PIA
__________________
Location:
Coastal South Carolina
rjniles is online now   Reply With Quote
Old 10-17-2011, 11:33 AM   #10
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by rjniles View Post
Typo, meant THWN.

OP, 100' is not a long run so voltage drop is not a real concern. I would run THWN in conduit(first choice) or direct bury UF. I would not run UF in conduit, a real PIA
I agree, but OP specifically asked if UF in conduit is legal. It is.
Code05 is offline   Reply With Quote
Old 10-17-2011, 11:37 AM   #11
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by ddawg16 View Post
And you might want to check...but you will most likley need a ground rod at the garage.
OP will need 2 if no other electrodes are present. Nobody I know even thinks about trying to test and use only one. Not worth it.
Code05 is offline   Reply With Quote
Old 10-17-2011, 11:42 AM   #12
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,340
Rewards Points: 2,342
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by Code05 View Post
I agree, but OP specifically asked if UF in conduit is legal. It is.
Only in vertical rise or horizontal run for a short distance to protect.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 10-17-2011, 12:04 PM   #13
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by gregzoll View Post
Only in vertical rise or horizontal run for a short distance to protect.
Greg, are you saying I cannot install a complete conduit system and pull UF through the whole run or are you defining where it is is necessary to sleeve the UF from damage?
Code05 is offline   Reply With Quote
Old 10-17-2011, 12:14 PM   #14
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,340
Rewards Points: 2,342
Default

NM Romex in conduit for detached garage??


I am saying that anything jacketed multi-conductor, with the exception of LV such as networking or a/v, should not be ran in conduit. In the case such as when we ran the UF for our garage, it is 3 feet from the sill plate to 18" under the ground. I used emt to protect, then where we have a tree, that we could not go under the roots, but was able to go about 12" under ground, I ran the UF through a short section of about two feet of conduit. Same when we got to the garage, but that section if I recall was about 4 feet.

That is the only time I would use conduit for UF, and if in a basement or garage, would use short enough to protect up to the ceiling for NM. Running conduit is a art, unless you cheat and use el's and t's that you have the screws to hold on emt, or glued for pvc, then I would run straight thhn or thwn depending on the location. I just looked downstairs, and I probably still have a thousand foot each on the spools downstairs of thhn, that I bought when we moved in in 2003. It is nice to keep on hand, especially in that I am going to have to run conduit out front for the porch light, when we put the new awning up. It was one of those things that I should have relocated when I had that section of roof open, but never did.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is online now   Reply With Quote
Old 10-17-2011, 12:22 PM   #15
Member
 
Code05's Avatar
 
Join Date: May 2009
Location: Easton MD
Posts: 1,841
Rewards Points: 1,000
Default

NM Romex in conduit for detached garage??


Quote:
Originally Posted by gregzoll View Post
I am saying that anything jacketed multi-conductor, with the exception of LV such as networking or a/v, should not be ran in conduit. In the case such as when we ran the UF for our garage, it is 3 feet from the sill plate to 18" under the ground. I used emt to protect, then where we have a tree, that we could not go under the roots, but was able to go about 12" under ground, I ran the UF through a short section of about two feet of conduit. Same when we got to the garage, but that section if I recall was about 4 feet.

That is the only time I would use conduit for UF, and if in a basement or garage, would use short enough to protect up to the ceiling for NM. Running conduit is a art, unless you cheat and use el's and t's that you have the screws to hold on emt, or glued for pvc, then I would run straight thhn or thwn depending on the location. I just looked downstairs, and I probably still have a thousand foot each on the spools downstairs of thhn, that I bought when we moved in in 2003. It is nice to keep on hand, especially in that I am going to have to run conduit out front for the porch light, when we put the new awning up. It was one of those things that I should have relocated when I had that section of roof open, but never did.

Greg, I do not like putting large cables in conduit either, my point is that if the OP wants to: he/she can as long as pipe fill and other factors allows it. It is a design choice.

Code05 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Garage Insulation yamster Insulation 0 07-01-2011 02:30 PM
Running conduit from attic to garage. raptor_demon Electrical 16 01-25-2010 10:12 PM
rewiring garage, questions about conduit pros and cons wombosi Electrical 32 05-08-2009 02:59 AM
Why not Romex in Conduit? Mr Chips Electrical 3 11-08-2008 10:58 AM
Use of unsheathed Romex NM-B wires in conduit? WoodworkerDave Electrical 10 09-29-2008 06:57 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.