Romex or individual conductors in conduit

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Old 10-11-15, 05:26 AM
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Romex or individual conductors in conduit

Okay, from what I'm reading, Romex should not go in EMT. So, how many wires should I pull for 4 x 20A circuits (neutrals, hots, 12-2, 12-3, etc.)? What size EMT?

Installing circuits to a crawlspace for two 10A heat cables, a bathroom blower heater, and a spare. Want to run the wire and EMT myself but have an electrician tie into the panel and install GFI outlets and switches. The EMT will pass through the garage wall, climb the exterior wall to the 2nd floor, and go through the soffit. Since I don't have a bender, was gonna use boxes at bend (unless the pipe must be one solid run - then I'll buy a bender).

Thank you, thank you, thank you so much for your assistance.
 

Last edited by GDeward; 10-11-15 at 06:20 AM. Reason: Clarity
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Old 10-11-15, 06:14 AM
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Raw wire? I guess you mean THHN individual conductors,have you checked to see if cables( NM-B )can be fished up to the second floor,maybe along side a stack pipe or vent pipe,I would definitely check with a licensed electrician to be sure he is OK with you doing part of the work.
Geo
 
  #3  
Old 10-11-15, 06:44 AM
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If your going to have an electrician connect the wires, you should be asking him how it needs to be run or if he's even willing to do the job with you doing part of the work before doing anything.
It would make more since to me to run just one set of wires to a new sub panel.
 
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Old 10-11-15, 07:20 AM
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Could we stick to facts? How many wires, code, etc.?
 
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Old 10-11-15, 07:41 AM
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Could we stick to facts?
We are sticking to the facts. The fact is if you pay an electrician chances are he will want it done his way. It is he who has to pass inspection and his license that is on the line. We can't guess how he wants it done and you shouldn't try.

Now if you want to do the whole job we can help you or if you want advice on if your electricians plans meet code we can help you.
 
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Old 10-11-15, 09:44 AM
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All of the points were in line with your questions.

Type NM cable can be run in conduit, but it cannot be used outside. There are also sizing rules for the conduit to maintain conduit fil, rules.
 
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Old 10-11-15, 02:53 PM
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1/2" EMT will be fine for 4 - 20 amp circuits. You can get up to 9 #12 THHN wires in a 1/2" emt. If you do not want to make box offsets you can use these: Raco EMT and Rigid/IMC 1/2 in. Hanger (5-Pack)-2052B5 - The Home Depot You can only have a max of 360 degrees of bends in a pipe run. I suggest keeping it to 270 degrees if possible for ease of pulling/pushing the wire in.

You may also be able to rent a bender. Please heed the others advice!
 
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Old 10-14-15, 08:04 AM
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If I ran THHN in 1/2" EMT for all four circuits (direct shot, no subpanel), what should I run? Would it be possible simply run FOUR 12-3 lines in the same raceway? If I run single THHN wires, what would I use? Is this even close to correct:

THHN #12 (four 20A circuits)
hot wire A
hot wire B
hot wire C
hot wire D
ground
neutral A
neutral B
 
  #9  
Old 10-14-15, 08:21 AM
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If you use the shared neutrals option, you need to use double pole breakers, and cannot use device feed through lugs for the neutral connections. You would probably want to split back out to four 12-2 cables from a junction box in the garage to make GFCI protection much easier.

If you put cables (e.g. 12-3 NM) in a conduit, the code specifies you have to calculate conduit fill assuming the cable is round with a diameter of the cable's widest dimension (assuming an oval or oblong cable). Conduit fill cannot exceed 40% of the cross-sectional area of the inside of the conduit. The code book has plenty of tables for THHN, but for cables you'd need to do the calculation yourself. My guess is maybe 1-1/4" conduit minimum.
 
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Old 10-14-15, 10:07 AM
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Whoa... 1.25" EMT? In my garage? And walls? How the heck do I bend THAT!?!? Geesh!

If I did ONE 12-3 NM in each raceway, could the raceways all use the same box when I need to punch through walls? Meaning, if you remove the cover you will see four 12-3 cables. Is this allowed?

I'm thinking of running four individual pieces of EMT (up, over, down, over) to a box and then punching through the sheetrock.
 
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Old 10-14-15, 10:41 AM
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It really sounds like you just need to let the electrician do the whole job. Still not clear why you even want to use conduit in the walls.
 
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Old 10-14-15, 01:08 PM
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I would say that running the NM through conduit is far more trouble than it's worth. Use individual THHN conductors in the EMT, and a large junction box at either end to transition to cables. You can pull 9 #12s in a 1/2" conduit. Four black, four white and one green ground. There's your 4 20A circuits in one 1/2" pipe. If you have more than 2 or 3 bends, you'll want to use 3/4" pipe to make the pull easier.

WRT to larger pipe, you can buy pre-made bends.
 
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Old 10-14-15, 08:57 PM
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Thanks, ibpooks. You've been quite helpful.

Last question: If I used 12-3 solid THHN cable OR 12-3 NM-B W/G cable, could I use a single 1/2" EMT for each within the garage, for protection, and run free in the attic? If so, then I could make a straight shot from the panel to the new outlets.

To clarify, the reason for the EMT was twofold. First, I want the wire protected in my garage. I'll be punching through a wall on the opposite side of my garage from where my main panel is. Second, I was trying to create an easier pass-through from my garage to my attic. I only NEED two of the circuits today and would rather only pull those cables / wire. Having the conduit (or two or four conduits) from my garage to attic will allow me to pull the other two circuits later on down the road.

The cables I'm considering:

Cerro 100 ft. 12-3 Solid THHN Cable-112-161253C - The Home Depot

Southwire 12-3 NM-B W/G (By-the-Foot)-63947699 - The Home Depot
 
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Old 10-15-15, 08:24 AM
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Home Depot really screwed the pooch on the product description of the Cerro Wire THHN. That is neither 12-3 nor cable. It should just be called #12 solid THHN, a.k.a. individual conductor wire. This type must be in conduit.

The Southwire product is cable, which is to say an outer jacket which contains two or more individual insulated wires. 12-3 w/g has a black, white, red and bare ground wires contained in an overall PVC jacket. NM cables can run without conduit through building spaces, but should be in conduit where subjected to damage. Your plan to run a single run of 12-3 in conduit for protection is OK.
 
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Old 10-15-15, 09:32 AM
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Wish I could shake your hand, ibpook, whomever you are. Thanks for such direct and responsive replies.
 
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Old 10-15-15, 11:10 AM
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Ben, that wire looks like all the conductors are packaged on one roll instead of 3 rolls of individual conductors.
 
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Old 10-15-15, 11:50 AM
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Ben I thought the same thing till after a lot of searching found this: SIMpull THHN® Cable with AlumaFlex® Conductors This is for commercial use.
APPLICATIONS
Southwire SIMPULL THHN cable with AlumaFlex conductors are primarily used in conduit and cable trays for servicesfeeders, and branch circuits in commercial or industrial applications as specified in the 2011 National Electrical Code.
 

Last edited by ray2047; 10-16-15 at 10:40 AM.
  #18  
Old 10-15-15, 04:59 PM
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Ben, that wire looks like all the conductors are packaged on one roll instead of 3 rolls of individual conductors.
That is exactly what it is. I've never seen it before so wonder if this is something geared to the weekend DIYer.

•Black, white and green wires
I don't think it would pull so easily though because of the resistance of the spiral of the conductors, kind of like trying to pull URD in conduit.

I see it isn't marked as cable by the manufacturer, but as "cabled".
 
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Old 10-15-15, 05:47 PM
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Joe asked:
I don't think it would pull so easily though because of the resistance of the spiral of the conductors
From: SIMpull THHN® Cable with AlumaFlex® Conductors
This cable should be installed without application of pulling lubricant.
 
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Old 10-16-15, 09:35 AM
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Interesting -- yeah I completely missed that. I've never seen that product before, and it's a little confusing as to why anyone would want it. Conductors twisting inside the conduit is usually a big pain in the butt during a pull. Pre-twisted conductors seem counter-intuitive, especially if you ever want to pull anything else in there.
 
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Old 10-16-15, 10:07 AM
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Conductors twisting inside the conduit is usually a big pain in the butt during a pull.
My thoughts exactly. It must be someone's idea that Cerro was the first to come out with. If it catches on, which I don't think it will, Southwire will also produce it. In commercial/industrial work it's actually pretty rare to just pull one 20 amp circuit into a conduit and many times just one circuit is installed with MC cable.
 
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Old 10-16-15, 10:20 AM
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And we are talking aluminum alloy so wouldn't you need #10 for 20 amps?
 
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Old 10-16-15, 10:34 AM
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Ray, the Cerrowire product linked by the OP is #12 copper.

Cerro 100 ft. 12-3 Solid THHN Cable-112-161253C - The Home Depot
 
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Old 10-16-15, 12:57 PM
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I have seen this concept in the trade magazines. Kind of like having the factory prefab the pulls on a spool.
 
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Old 10-16-15, 01:31 PM
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Cerrowire product linked by the OP is #12 copper.
OOPs. I missed that. Thanks for the correction. I was going by my search.
 
 

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