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Old 10-25-2009, 12:15 AM   #1
tlj
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Running ROMEX into Conduit


I am remodeling an old cabin and I need to add new branch circits. I have run 2" SCH 80 conduit from meter/main to crawl space where it comes out as 2" conduit. Now I am stumped. I don't want to just run romex through conduit because I would fill it up too quickly. I am already aware (thanks to this forum) that I cannot just strip the romes and continue the wire. Do I add a junction box in the crawl space? Suggestions are welcome.

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Old 10-25-2009, 12:21 AM   #2
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Running ROMEX into Conduit


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I am remodeling an old cabin and I need to add new branch circits. I have run 2" SCH 80 conduit from meter/main to crawl space where it comes out as 2" conduit. Now I am stumped. I don't want to just run romex through conduit because I would fill it up too quickly. I am already aware (thanks to this forum) that I cannot just strip the romes and continue the wire. Do I add a junction box in the crawl space? Suggestions are welcome.
How many circuits are you adding? A common solution here (which may not be technically code compliant, but is widely used and accepted) is to simply run the romex through conduit. Assuming this is a short, mostly straight run, the conduit is acting as a sleeve not a "raceway" for code purposes. The bundling derating for NM cable may be an issue depending on how many circuits you are running.

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Old 10-25-2009, 12:26 AM   #3
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Running ROMEX into Conduit


Yes you will have to add a junction box and I really doubt the big box store may not stock this size however electrical supply centre no question asked they will have it on hand.

For the size I always go at least 6X of conduit size { it work fine in most case } so you allready installed 2 inch conduit so you will need 12X12X6 steel or PVC junction box and some will have prepunched KO forum and some don't have any KO prefourmed at all so you will need a hole saw to punch in a multi holes for sure PVC you will need hole saw no question asked.

Merci.
Marc
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Old 10-25-2009, 01:00 AM   #4
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Running ROMEX into Conduit


I am adding all kitchen circuits, 1-50A, 2-30A, and a few other 20A circuits. I think the 2" conduit would fill up pretty quickly with Romex. It sounds like a junction box is the way to go, and thanks for help in sizing it. I will look for something next time I get back to town.

Now, if I did run Romex through the conduit, I have an other question. Can I just run the romex straight into the conduit? Does it need a bushing? Romex is normally clamped into a box once it enters it. Is there a clamping requirement when the Romex, enters the main load center? If so, how?
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Old 10-25-2009, 01:32 AM   #5
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Running ROMEX into Conduit


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I am adding all kitchen circuits, 1-50A, 2-30A, and a few other 20A circuits. I think the 2" conduit would fill up pretty quickly with Romex. It sounds like a junction box is the way to go, and thanks for help in sizing it. I will look for something next time I get back to town.

Now, if I did run Romex through the conduit, I have an other question. Can I just run the romex straight into the conduit? Does it need a bushing? Romex is normally clamped into a box once it enters it. Is there a clamping requirement when the Romex, enters the main load center? If so, how?

To answer your first question if you ran with Romex in the conduit you will fill it up pretty quick and it don't take much at all.

Now as I mention large 12X12 junction box what you do is bring in romex cable to the junction box from there you will switch over to THHN/THWN conductor it will take far less room to fill in the conduit but the derating will go in effect due the numbers of current carry conductors so let me give you a quick run down how it shake it down.

50 amp circuit so that is the Range so just be aware this is a 4 conductor not three conductor set up per NEC code and I will use #6 THHN/THWN { three will be at #6 the fourth one will be at #10 due it will be under 60 amp breaker so that is legit set up I will fill in the rest in a minute as I get the rest of figures in }

2 X 30 amp circuit however this part you may correct me on this one but i will pretty much figured out you will have one dryer circuit and one electric water heater { tank type } so dryer will have 4 conductor while water heater will have three conductor ( two hot and ground )

you say few 20 amp circuits so I will set this at 5 circuits for now so that way you have some wiggy room here { hard to say the word few so it kinda cover the base }

now here what I will do this

Bring out #10 bare grounding conductor or green conductor that will cover the largest breaker and still meet the code { for all green and bare ground conductors just wirenuted them together or get a grounding bussbar { best move on this one }

3- #6 THHN/THWN { that for range}
5 - #10 THHN/THWN { one set for dryer and second one for electric waterheater }
10 - #12 THHN/THWN for 5 X 20 amp circuits

you can able use the 2 inch conduit without issue however I did ran into small snag I have to get my NEC code book to double check the derating numbers if not line up right I will post it ASAP otherwise one of other members here will chime in and give you the correct answer.

{ I did converted from AWG to Metric to AWG size due I have a European verison of Electrician caluatior with me I left the NEC { North America verison } back home. so it should come up pretty close }

Merci.
Marc

Note : the numbers may not line up right so please hold on to that figures I will make couple reversions to crush around to keep it legit.

Last edited by frenchelectrican; 10-25-2009 at 01:47 AM. Reason: add a note
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Old 10-25-2009, 12:17 PM   #6
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Running ROMEX into Conduit


I would just run the romex thru the PVC. There will be plenty of room if you keep the cables straight and do it cleanly.

If the conduit is longer than 24" it is a technical violation but is accepted in many areas. It's much better than adding dozens of splices in a jbox.
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Old 10-26-2009, 09:33 PM   #7
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Running ROMEX into Conduit


Update of THHN. There is a lot of confusion as to whether the cable in Romex is THHN or not. A quick Internet search reveals hundreds of companies selling wire who claim that the wire in Romex is THHN. Most electricians maintain that when transitioning from Romex to single conductors in a JB they cannot use stripped Romex but must use THHN wire. I examined what I had on hand and found that some of the conductors in Romex had a clear outer coating which is probably Teflon, and some did not. None of the Romex wire samples I looked at had markings on them as does THHN. I think the bottom line is, that you have to go on what is marked on the cable which is the NEC way.
So, I called my Electrical Inspector and he confirmed that there is a lot of confusion, but if I wanted to strip back Romex to the JB and run individual conductors through the conduit, it was OK with him. I assured him that I would only do it with cables that looked like they had a teflon outer coating. I would prefer not to cut a perfectly good wire and splice in an other perfectly good wire resulting in an unnecessary splice.
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Old 10-26-2009, 10:31 PM   #8
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Running ROMEX into Conduit


Tlj:

I just want to give you a head up with the list I have above from yesterday finally got my NEC code book out of my storage I do keep it for handy and I will say I did ran into a blunder I oversighted with derating however.,
I need your confirmation realted to 120 volt 20 amp circuit are you going with three or four or five circuits ?


The reason why I did count the number of conductors in the conduit it will really cut the ampcaity in half so if you want to add a second conduit that will only reduce a little compare to single large 2 inch conduit and how long this conduit it will be exposed or used ?

{ a nice gotcha if you keepthe conduit under 24 inches then the restriction is not enforced }

Merci.
Marc
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Old 10-27-2009, 11:58 AM   #9
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Running ROMEX into Conduit


I'm not sure why you are going to strip Romex when it is against code
The fact that your inspector will allow it doesn't change anything
How far is the run from meter/main? (main panel?)
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Old 10-27-2009, 12:37 PM   #10
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Running ROMEX into Conduit


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I'm not sure why you are going to strip Romex when it is against code
The fact that your inspector will allow it doesn't change anything
What the pumpkin said.
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Old 10-27-2009, 07:58 PM   #11
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Running ROMEX into Conduit


Derating your conductors due to the number of "current carrying conductors", or "ccc", in the same conduit are going to kill ya.

(2 ccc) for the 50A circuit
(4 ccc) for the two 30A circuits
These alone give you 6 ccc, which means you have to derate the allowable ampacities of your conductors to 80% of their values in Tables 310.16 thru 310.19 of the NEC. Not a problem.

Throw in one of your 20A circuits (+2 ccc, total of 8 ccc), puts you at 70% of the table values. Not so bad.

Throw in one more of the 20A circuits (+2 ccc, total of 10 ccc), puts you at allowable ampacities of 50% of the values listed in the tables. What does this mean? You would need bigger wires for the same circuits.

Sounds like a perfect time to put in a subpanel. Use the 2" conduit to feed the sub.
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Old 10-27-2009, 08:17 PM   #12
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Running ROMEX into Conduit


Do NOT strip the sheath off. Yoy are going to end up with a clusterflock of unmarked wires. If you ever have to troubleshoot or ring out a circuit, you need to know which neutral goes with which hot.

There is no confusion about NM cable being thwn wire...it's not. It may be the same exact wire but if it doesn't say thwn, it aint thwn. In most areas they don't give it a second thought because it will never ever be a problem. There are hard nosed inspectors in some areas that will turn it down, but not in your case.
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Old 10-27-2009, 08:27 PM   #13
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Running ROMEX into Conduit


Tlj;
I am kinda suprised that your inspector allow it here my Inpsectors they will say no way both in Wisconsin and France.

You wil have to come up differnt way to slove the issue with conduit run and NEVER I will repeat JAMAIS { Never in French } strip the NM off otherwise you will get into such heckva a mess you will not able sorted out if not marked with number on it and what more almost all NM I know in both USA and France they hardly print anything inside of the NM conductors!

Merci,Marc
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Old 11-05-2009, 06:02 AM   #14
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Marc...

I was somewhat surprised too. However, this is Idaho, and what happens in Idaho stays in Idaho . The inspector also said I could pull as many Romex cables as I could stuff into 3-Ft of conduit (but I wont). Elsewhere I believe the length is 2-ft.

As far as losing track of cable pairs, don't you have the same problem with THNN? I am labeling each pair on both ends with a sleeve made from the yellow jacket of Romex and a Sharpie, indicating the branch circuit each pair feeds.

Thanks again for your responses.

...tlj

unrelated afterhought:
I was off-line a few days working on my cabin, and installing WIndows-7 at home. In my experience Windows-7 RC1 was better that the final release. Some printer drivers don't work and I have had problems installing other programs that installed just fine under RC1. Microsoft must have acknowledged this by laying off another 800 persons, problably those responsible for the oversight.
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Old 11-05-2009, 06:46 AM   #15
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The inspector also said I could pull as many Romex cables as I could stuff into 3-Ft of conduit (but I wont). Elsewhere I believe the length is 2-ft.
...tlj
If it's only 3' then I see no point in violating code by removing the romex
If you need more room run another 3' section of conduit

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