EMT electrical conduit -- how many NM wires?

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I have a dedicated 15-amp circuit in an unfinished basement that runs to an outlet on the wall for the sump pump. The wire/cable that goes to the outlet is white 14/2 NM-B w/ground. From the ceiling down to the outlet it is fed inside of metal EMT conduit. I assume that the metal conduit is 1/2-inch (the outside diameter of the conduit is about 3/4-inch).
I would like to add a pull string ceiling light above the sump pump for better lighting while working on the sump pump and/or the HVAC which is next to the sump pump.
What I am thinking of doing is getting power for the light from the outlet and running new 14/2 NM-B w/ground from the existing outlet back up through the same EMT metal conduit to the new ceiling light.
My main question is, is it okay to have two 14/2 NM-B w/ground cables inside a 1/2-inch EMT metal conduit?
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On Friday, July 12, 2013 1:01:12 PM UTC-7, TomR wrote:

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You can’t have any NM cable inside a conduit. It has to be single conductors.
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On Fri, 12 Jul 2013 13:15:41 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

Wrong
334.15 Exposed Work. In exposed work, except as provided in 300.11(A), cable shall be installed as specified in 334.15(A) through (C).
(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means.
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On Friday, July 12, 2013 1:58:08 PM UTC-7, snipped-for-privacy@aol.com wrote:

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Even in that exception the conduit would have to be larger than ½” so a s not to exceed the fill capacity.
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On Fri, 12 Jul 2013 16:32:46 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

Not true at all for a single 14-2 NM. A single conductor or cable can fill 53% of a raceway but when you get to two, that drops to 31%
Ok to make the math easier this is metric Using Southwire RX
width...........area 14-2 9mm ...63.6 mm2 12-2 10mm..78.5 mm2 14-3 7mm....38.5 mm2 12-3 8mm....50.24 mm2 10-3 9mm....63.6 mm2
From Table 4 Trade size..one wire 53%...2 wires 31%....3 or more 40% 1/2"EMT....104 mm2 ...........61mm2............78mm2 3/4"EMT....102 mm2 ...........106mm2...........137mm2 1" EMT......295 mm2 ...........172mm2...........222 mm2
Two 14-2 RX would need a 1" EMT to be legal.
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On 7/12/2013 11:31 PM, snipped-for-privacy@aol.com wrote:

1" PVC might be easier to handle and install but I don't know about the capacity. It's been a while since I installed any and I often used calipers to compare the inside of different types of conduit when planning a job. Scrap pieces of conduit and wire come in handy when you want to do a practical measure of what you're installing especially when it's signal or network cables that may not appear in any tables. Any of the phone system or computer network installations I've done have 3/4" EMT run to every phone or network outlet inside any wall but the wires are not carrying any significant power. It makes it easier to install the wires, besides, I'm lazy. ^_^
TDD
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snipped-for-privacy@gmail.com wrote in

Absolute nonsense. NM cable is permitted inside conduit in any location where NM is permitted without conduit.
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On Friday, July 12, 2013 2:15:55 PM UTC-7, Doug Miller wrote:

here NM is

NEC Note 9 in the Chapter 9 tables says "A multi conductor cable of two or more conductors shall be treated as a s ingle conductor for calculating percentage fill area. For cables that have elliptical cross section, the cross section area calculation shall be base d on using the major diameter of the ellipse as a circle diameter".
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snipped-for-privacy@gmail.com wrote in

How on earth did you manage to read that as prohibiting NM inside conduit?
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On Friday, July 12, 2013 5:20:47 PM UTC-7, Doug Miller wrote:

?
It exceeds 53% of the area for ½” conduit.
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snipped-for-privacy@gmail.com wrote in >> >> > You can't have any NM cable inside a conduit.

All that proves is that _that_particular_combination_ can't be run in _that_particular_size_ of conduit.
You made the blanket claim that "You can't have any NM cable inside a conduit" -- which is complete and utter nonsense.
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On 7/12/2013 9:37 PM, Doug Miller wrote:

And now that he's been shown to be wrong, he's back peddling, trying desperately to look like he's still correct. Wait for it, we'll soon see the be-all, end-all answer of "BECAUSE! That's why!" <g>
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On Friday, July 12, 2013 7:37:03 PM UTC-7, Doug Miller wrote:

uit ?

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duit" -- which is

For that matter you can make an air conditioner that runs on water instead of Freon if you made the pipes about a foot in diameter. It would work but wouldn’t be practical.
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snipped-for-privacy@gmail.com wrote in

made the pipes about a foot in diameter. It would work but wouldnt be practical.

What in the world does that have to do with whether NM is permitted inside conduit or not?
Perhaps you should sober up before you post again.
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On 07/12/2013 04:01 PM, TomR wrote:

I don't know the answer to that question as I'm used to seeing THHN instead... I'm assuming the reason for using NM is that the EMT just terminates at a bushing above the ceiling, and is only used for protection of the cable?
Is the recep in a 1900 (4" square) box or a handy box? If a 1900 box I would just get another stick of EMT and do it that way. (don't forget the bushing where the EMT terminates, to prevent chafing the NM.) If it is a handy box you probably don't have enough room in the box to legally add more conductors anyway, and should consider replacing it with a 1900 box.
nate
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On 7/12/2013 4:01 PM, TomR wrote:

If you run NM inside of metallic conduit, the metal should terminate in you box using a proper fitting. At the other end of the conduit sleeve, there should either be a choke or a bushing on the end of the conduit and a staple into some framing near the end of the conduit. If you need more cable entries in the box, use additional sleeves
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RBM wrote:

Thanks. That's how the conduit and wiring is set up now -- with the right fittings clamps, etc.

Okay.
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The problem is conduit fill. You can't put that many NM cables in a 1/2" EMT
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Probably not physically possible anyway... but no, not as far as I know.
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Doug Miller wrote:

Thanks Doug, gfretwell, RBM, Nate, et al.
I have another option that I think will work. The existing 14/2 NM cable runs along the side of a ceiling joist close to where I want to put the new light. Most likely, I can just unstaple that cable and create enough slack to place a junction box in the circuit there and run the light from that junction box. Or, if that doesn't create enough slack, I could just use two junction boxes.
But, before doing that, I thought that I would check to see if I could do my original idea of having two NM cables in the one 1/2-inch metal conduit -- apparently not.
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