Romex in conduit?
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Mickey O
Well-known member
It's true that can not run romex in EMT or PVC but there are other types of wires that you can run in them, THWN and others.
Aceman
Well-known member
Where in the code book does it say I can't run Romex in conduit?
Mickey O
Well-known member
Out here it's illegal in the code (we're on several versions of the NEC modified, varies from town to town), no romex allowed in most Chicagoland areas, but you can buy it at the local Wal Mart and Menards. I probably shouldn't say you can't, you can do what ever you want, but in many case you end up violating the NEC fill capacity code for the conduit so it would be a violation. I suppose if you use a large enough conduit it would be no problem but would be a waste of money unless someone gave you a pile of free romex and conduit. I believe you also have to derate the wire capacity. Now if he's talking about a sleeve to prevent damage it's a little different. You could also get into the NEC rules for using the product per manufacturers instructions and UL testing.
jkeyser14
Well-known member
The only time you can run romex in conduit is when you are dropping it from a protected area to a non-protected (but needs to be protected) area. For example, if you had a finished ceiling in your basement but didn't have finished walls, and you were putting in a new hot water heater, code would allow you to run romex in the ceiling, and then into conduit running down to a disconnect. And any time you go from outside of conduit to inside of it you need to make sure you have the proper fittings on the end. In the example above where the transition isn't inside a junction box, there would need to be a fitting with a cable clamp to prevent the cable from rubbing on sharp edges as it transitions into the conduit.
The reason for the code is that Romex has an extra layer of insulation, so the code gods are worried about overheating it in an enclosed space (conduit). If you look at specs though, type NMB Romex (any romex made in the last 15 years) and THHN have the same temperature ratings
. Also, romex is run in insulated walls which would lead me to believe the "enclosed space" argument is a moot point. Still, it's a good idea to cover your **** and use THHN.
The reason for the code is that Romex has an extra layer of insulation, so the code gods are worried about overheating it in an enclosed space (conduit). If you look at specs though, type NMB Romex (any romex made in the last 15 years) and THHN have the same temperature ratings
. Also, romex is run in insulated walls which would lead me to believe the "enclosed space" argument is a moot point. Still, it's a good idea to cover your **** and use THHN.'cause my walls are made out of concrete and it's rather difficult to snake wires through.
I have about 60' of wall with no outlets I need to string up...Yeah, I'm just mad because I can only buy it in 500' rolls and I need 5 colors. I DON'T need 2500' of wire, but I also don't want to pay $0.24/foot either...
Mickey O
Well-known member
The only time you can run romex in conduit is when you are dropping it from a protected area to a non-protected (but needs to be protected) area. For example, if you had a finished ceiling in your basement but didn't have finished walls, and you were putting in a new hot water heater, code would allow you to run romex in the ceiling, and then into conduit running down to a disconnect. And any time you go from outside of conduit to inside of it you need to make sure you have the proper fittings on the end. In the example above where the transition isn't inside a junction box, there would need to be a fitting with a cable clamp to prevent the cable from rubbing on sharp edges as it transitions into the conduit.
The reason for the code is that Romex has an extra layer of insulation, so the code gods are worried about overheating it in an enclosed space (conduit). If you look at specs though, type NMB Romex (any romex made in the last 15 years) and THHN have the same temperature ratings
Technically I think you could run romex in conduit if you used the right size conduit and properly derated the wires, unless it was specifically prohibited like it is out here. But again, it would seem like a waste of money and a pain in the **** to pull it.
Charles (in GA)
Well-known member
As Aceman said, where in the code book does it say you cannot? Chapter 9 -Tables- in the back of the NEC has all the conduit fill info and even tells you how to calculate the area of an eliptical cable (Romex for instance), and also tells you to treat a multi-conductor cable as a single conductor for fill calculations; the various article sections on conduits and raceways do not forbid it, Article 334 on NM cable doesn't forbid it, so unless its local AHJ that forbids it, where does it say you cannot?
That said, I think anyone that wants to try to run Romex in conduit for any distance is crazy. Been there, done that, got the prize. It isn't worth the effort, no amount of cable lube in the world will help it and it simply doesn't pull easy enough to make me want to ever again try.
Charles
That said, I think anyone that wants to try to run Romex in conduit for any distance is crazy. Been there, done that, got the prize. It isn't worth the effort, no amount of cable lube in the world will help it and it simply doesn't pull easy enough to make me want to ever again try.
Charles
Aceman
Well-known member
You guys are making up NEC code..
I can pull Romex in a mile long conduit all day long as long as I size it right. There is no extra "derating" for Romex. Until you guys post something factual(NEC code article), I'm calling BS.
Some folks seem to think that there local amendments should apply to everyone, well, they don't. Let's stick to what the NEC has to say about it...
I can pull Romex in a mile long conduit all day long as long as I size it right. There is no extra "derating" for Romex. Until you guys post something factual(NEC code article), I'm calling BS.
Some folks seem to think that there local amendments should apply to everyone, well, they don't. Let's stick to what the NEC has to say about it...
LoneGunman
Well-known member
Yup, if you can't site an article number then it don't exist NATIONALLY. I don't think there is any good reason to do it, unless coming down a wall.
Falcon67
Well-known member
I use 3/4" in the shop and usually limit a pull in that to 2 romex cables. If I need more, I'll use 1" or better. Haven't yet, all are just plug runs and I like the conduit as protection from flying objects. Amazing what damage a 7/16" wrench can do when that header won't go back on the motor right. If you take a little time to pre cut and unwind the romex, a little GoJo on the end and it'll slide right through. A single run will easy fit in 1/2, but most boxes have more 3/4" holes than 1/2, so I just buy the 3/4.
[edit] - also, I just use the conduit for drops and wall runs, up in the attic the wires are run along something and stapled. I have 3 12 gauge runs that go to the far end across rafters, I just ran those in some extra 1 1/2" PCV for protection - because I had it.
I can see the argument - you can buy 250' of 12-2 for under $50 (last time I looked) and a single 500' spool of black runs you $122 at Grainger. Not on most peoples budget.
[edit] - also, I just use the conduit for drops and wall runs, up in the attic the wires are run along something and stapled. I have 3 12 gauge runs that go to the far end across rafters, I just ran those in some extra 1 1/2" PCV for protection - because I had it.
I can see the argument - you can buy 250' of 12-2 for under $50 (last time I looked) and a single 500' spool of black runs you $122 at Grainger. Not on most peoples budget.
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sberry
Banned
For the OP, pipe it up the wall. 5 ft of pipe wont hurt anything.
Scotto
Well-known member
I have a similar deal in my basement. I have romex running down to the outlets now, but I'd like to run it in some kind of conduit. I've already had a scare with something falling and cutting the jacket of the romex.
Charles (in GA)
Well-known member
Lowes has 500 ft spool of THHN, 12 ga solid, all colors, for $50 a spool. I think HD is about the same.
Charles
Falcon67
Well-known member
Hadn't looked - that's more like it, I'd buy that.
jvitez
Well-known member
Exactly the situation I'm facing. I'll either run Romex in conduit or build an enclosed raceway to protect the NM-D until it goes up into the attic.
Do you have a link to the type of fitting you're describing?
I understand if using a junction box you would run the conduit into the JB, pull the NM-D through the conduit, into the and out of the JB, and use a standard fitting like that for entering into a load center where the Romex comes out of the junction box into the attic space. Right?
Mickey O
Well-known member
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Mister B
Member
I did the same thing. I ran my romex cable stapled along the joist in the basement and then into EMT conduit starting at the top of the block wall and down the concrete block basement wall to a receptacle.
This is what the fitting I used at the top of the conduit looked like. It clamped the romex cable to the conduit so that it would not move. Sorry for the huge picture, it is all I could find.
This is what the fitting I used at the top of the conduit looked like. It clamped the romex cable to the conduit so that it would not move. Sorry for the huge picture, it is all I could find.
jvitez
Well-known member
This site is fantastic! Thanks guys.
Falcon67
Well-known member
Maybe I'm not looking hard enough, but I haven't been able to find the bushings or one of those cap/clamp things in my usual shopping spots.
djjsr
Well-known member
If there's a Menards near you, they have smaller spools of wire. If you're running conduit anyway, it'll be cheaper than using romex.
Grumpy365
Well-known member
, look at 334.12(B)(4) and 300.5(B) and 300.9 ..
The result is no Romex in a conduit in a wet or damp location.
So as long as your 1000 foot is inside you may be right
Mickey O
Well-known member
Canada has completely different rules/codes.
A EMT connector, rigid coupling, & a romex connector would be a substitute.
octavio3311
Well-known member
There's nothing wrong with running 12/2 in EMT conduit and dropping it down from the ceiling into your receptacle box! Just make sure you get an anchor kit for your hammer drill and secure the EMT and your receptacles to the concrete wall. THHN would be easier - but hey - that's up to you!
scottybaccus
Well-known member
I spent many years pulling romex through both emt and pvc for yard lights and water wells, some many hundreds of feet. I sure did get by with a lot of inspections somehow if there is anything in the NEC prohibiting such installations.
Well, thanks for the info everyone. I thought there was some NEC thing about not allowing romex in conduit. I'll just use the romex since I'm not going very far and I won't be inviting anybody to come inspect inside my conduit. If it's safe enough not to be prohibited by the NEC, then it's safe enough for my shop. I'll only be pulling it 10' at a time, so I don't think it will be too hard. Hell, the last guy in my shop just stapled 14/2 anywhere he needed it...attached to 20A breakers. 
I wish I could run more of it in the attic, but it was apparently designed for birds and squirrels to live in...not for 200# men.
If it's safe enough not to be prohibited by the NEC, then it's safe enough for my shop. I'll only be pulling it 10' at a time, so I don't think it will be too hard. Hell, the last guy in my shop just stapled 14/2 anywhere he needed it...attached to 20A breakers. I wish I could run more of it in the attic, but it was apparently designed for birds and squirrels to live in...not for 200# men.
The inspectors must have been looking the other way as the NEC prohibits romex outdoors, let alone in conduit. Maybe you were pulling UF in conduit and call that romex?
Mickey O
Well-known member
Okay, I'm running 3 12-2 (welder, compressor, outlets- each on a 20 amp breaker) and 1 14-2 (lights - 15 amp breaker) in romex in EMT conduit, tell me what size conduit to use, or if I can even do it.
Its less than 9 current carrying conductors so it shouldn't be a problem
Aceman
Well-known member
I don't have to tell you anything.
Stuart in MN
Well-known member
No. A 1/2" conduit is way too small for one piece of romex, let alone two.
Charles (in GA)
Well-known member
Chapter 9 of the NEC titled "Tables" says in "Notes to Tables", note (9), A multiconductor cable or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit fill area. For cables that have ellipticall cross sections, the cross-sectional area calculation shall be based on using the MAJOR diameter of the ellipse as a CIRCLE DIAMETER
What this is saying, is that, when you install a multi-conductor cable such as romex in conduit, a single romex pull would be a single conductor and have a 53% fill limit, while two conductors (two separate THHN wires or two Romex pulls) would have a 31% fill limit and more than two conductors would have a 40% fill limit...... the limits are specified in Table 1 of Chapter 9........... AND you would take the fattest width of the romex and calculate the area using the simple Pi times the radius squared formula. Thus a typical 12/2 w/grd Romex that measures about .375 the wide way, is .375 divided by 2 equals .1875 and that squared is .03516 times Pi (3.1416) is .1104 square inches of area PER ROMEX. Table 4 of Chapter 9 tells us that for a 1/2 conduit the 53% (one conductor) fill is .182 and the 31% (two wire) fill is .094 and the 40% (three wire) fill is .122
Thus a single 12/2 Romex is all that will fit in a 1/2 EMT conduit.
Looking at 3/4 EMT, the two wire 31% fill is .165 so two Romex pulls will not go in 3/4 either. You have to go all the way to 1" EMT to get a two wire fill large enough, .268 to accommodate two pulls of Romex.
HOWEVER, all of this being said............ Note (2) tells us that the conduit fill limits of Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring from physical damage. While I thought there was a length limit to use of EMT as physical protection and not as a complete system, I cannot find it in the code right now.
That being said, common sense tells us that when you have a 1/2 conduit whose 100% fill is .304 sq in, and a ID of .622" that two 12/2 Romex cables will not fit in it very well if at all.
Charles
What this is saying, is that, when you install a multi-conductor cable such as romex in conduit, a single romex pull would be a single conductor and have a 53% fill limit, while two conductors (two separate THHN wires or two Romex pulls) would have a 31% fill limit and more than two conductors would have a 40% fill limit...... the limits are specified in Table 1 of Chapter 9........... AND you would take the fattest width of the romex and calculate the area using the simple Pi times the radius squared formula. Thus a typical 12/2 w/grd Romex that measures about .375 the wide way, is .375 divided by 2 equals .1875 and that squared is .03516 times Pi (3.1416) is .1104 square inches of area PER ROMEX. Table 4 of Chapter 9 tells us that for a 1/2 conduit the 53% (one conductor) fill is .182 and the 31% (two wire) fill is .094 and the 40% (three wire) fill is .122
Thus a single 12/2 Romex is all that will fit in a 1/2 EMT conduit.
Looking at 3/4 EMT, the two wire 31% fill is .165 so two Romex pulls will not go in 3/4 either. You have to go all the way to 1" EMT to get a two wire fill large enough, .268 to accommodate two pulls of Romex.
HOWEVER, all of this being said............ Note (2) tells us that the conduit fill limits of Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring from physical damage. While I thought there was a length limit to use of EMT as physical protection and not as a complete system, I cannot find it in the code right now.
That being said, common sense tells us that when you have a 1/2 conduit whose 100% fill is .304 sq in, and a ID of .622" that two 12/2 Romex cables will not fit in it very well if at all.
Charles
You cannot re identify a conductor smaller then 4 AWG either white or green.
Aceman
Well-known member
Charles, conductor fill doesn't apply to sleeves used for physical protection.
The reference is in the Notes to Tables #2 on the first page of Chapter 9.
The reference is in the Notes to Tables #2 on the first page of Chapter 9.