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Old 02-10-2015, 08:16 PM   #1
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From Panel to Attic Junction through 1 1/2 Conduit


First, I really appreciate everyone offering advise and education on these forums, its been quite helpful.

I fear I may need to re-do part of the work I started based on some previous advise elsewhere before its too late.

I have a house with old wiring. I am replacing the wiring with #12 wire and wanting to put in a few 20 amp circuits.

So originally I thought to run several circuits through the 1 1/2" conduit. I thought I had the right information, but now I am really doubting myself based on a number of posts in this forum.

The inside image shows conduit with an upward angle. The thought had been that with such a low angled roof, this extension and 45 degree angle would make it easier to access after everything was closed up and insulation was laid back in.

Based on my previous, possibly misunderstood DYI education, I ran 8 cables of 12/2 rommex through the conduit. Yes, it was a major pain, I did 4, then 4 more.

Now I am wondering if I should pull it all back out and fix it, so here are my questions:

1) Does it need to be fixed or is it ok as is?

If it needs to be fixed, do I:

1) Cut the conduit down closer to the wall like the older conduit?
2) Run multiple #12 THHN wires?
2.1) Are there any suggestions or standards for multiple colors in the same conduit?
2.2) These will be on ARC Fault breakers, so do I run back a white wire for each circuit and mark it somehow?
2.3) I can run back a single ground #12 wire, correct?

Or rather than ask a bunch of questions, what is suggested based on your experience?

The location if it matters code wise is San Diego County (not city) in California.

I know the other loose cables there look bad, its from part of the old wiring and is some of the stuff I am trying to clean up and the outside picture was taken before the conduit was secured.
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Old 02-10-2015, 08:38 PM   #2
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From Panel to Attic Junction through 1 1/2 Conduit


You wasted your time . You can't run all that romex in conduit that distance outside. Then you get into derating factors of conductors. Then bundling of cables. Sorry, imo,
Call an electrician.

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Old 02-10-2015, 09:06 PM   #3
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From Panel to Attic Junction through 1 1/2 Conduit


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You wasted your time . You can't run all that romex in conduit that distance outside. Then you get into derating factors of conductors. Then bundling of cables. Sorry, imo,
Call an electrician.
Thanks for the reply, although its sad to hear. I was really hoping this was something I could end up doing. All of the old cabling is 14/2 and 12/2 cable running through the smaller conduit.

Any chance this could still be resolved by reducing the number of NMB cables and removing the "indoor" (image) conduit making it flush with the wall like the other lines coming in??

If it were possible, how many NMB wires could safely be pulled through the conduit?
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Old 02-10-2015, 09:26 PM   #4
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From Panel to Attic Junction through 1 1/2 Conduit


NM cannot be used outside, even if in conduit.
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Old 02-10-2015, 10:06 PM   #5
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Where in the NEC does it say you cant? You do have to derate though. Why not use single conductors in the pipe? Make it much easier
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Old 02-10-2015, 10:54 PM   #6
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Where in the NEC does it say you cant? You do have to derate though. Why not use single conductors in the pipe? Make it much easier
this is from the 08 code but:

334.12(B)(4)

NM shall not be used under the following conditions or in the following locations:

in wet or damp locations




conduit, out side, is considered a damp location.
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Old 02-10-2015, 11:28 PM   #7
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Thanks for the replies,

I realize there is a lot of debate around this issue, which is why I decided to seek more help and education here from all of you. I am not in a rush to do it wrong, so I don't mind doing it right, but I do want to learn how to do it right and not just pay someone if learning it is possible. I've done a lot of the work past the jbox over the years, and its been 15+ years since last I can remember pulling cables on the construction job, but that was as an assistant.

From what I've gathered, I understand that outside conduit is considered by NEC 334.12(B)(4) and 300.9 basically state that NM cannot be run in 'wet' locations and any conduit outside is considered to be a 'wet' location. Granted, it does appear that this is a more recent (last 4 years?) clarification and a ton of electricians have done as I did running NMB through conduit to the outside. Searching through this forum before I posted I knew this seems to be a constant point of discussion\debate.

So I understand I need to run THWN rated conductors. I don't mind pulling the cable back out to do this and replacing with single conductors in the conduit.

I'm just learning how to derate, so I am reading up on that but any guidance is greatly appreciated. My end goal is to get as many 20 amp circuits through this conduit as is safe, to a set of junction box(es) in the attic so I can better separate the electrical as I remodel the house. Our entire house is currently running off of a single 20 amp and a few 15 amp circuits and the existing wire is falling apart.

So now that I know I need to remove the NM and put in THWN, what is the proper way to do this getting it to the jbox in the attic? Do I have to run conduit all the way or do I just secure the wires? I've read conflicting views on this. We do not have attic rodent problems in this area.
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Old 02-10-2015, 11:49 PM   #8
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From Panel to Attic Junction through 1 1/2 Conduit


I believe the statement I posted was new in the 08 code. I suspect it was simply meant as a clarification rather thst a new rule.

Individual conductors must be in conduit at all times.

It's late for me so I'm not going to get into the deratjng tonight. I'll be back tomorrow
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Old 02-10-2015, 11:52 PM   #9
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San Diego eh? We use THHN everywhere here in imperial valley. Just use single conductors. 16 current carrying conductors should be fine in 1.5inch pvc.
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Old 02-10-2015, 11:53 PM   #10
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Your allowed to secure NM in the attic
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Old 02-10-2015, 11:58 PM   #11
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Quote:
Originally Posted by nap View Post
I believe the statement I posted was new in the 08 code. I suspect it was simply meant as a clarification rather thst a new rule.

Individual conductors must be in conduit at all times.

It's late for me so I'm not going to get into the deratjng tonight. I'll be back tomorrow
NAP thanks. I think I actually might have figured out derating and the answer to my question.... but I need to validate the ambient temperature. NEC doesn't seem to define if I should use year round average as opposed to summer month temps.

Using summer month temps and THWN #12 90C conductor, I believe I use 30 amps for the derating calculation and ended up with between 21.84 (normal summer) and 20.88 (hot summer) as the derated ampacity assuming I use no more than 6 current carrying conductors (6 black and 6 white plus grounding).

This all would be different if I were to have a conduit run of 24" or less.... which at the moment I don't think is possible due to the punch outs on the box available to me.

Hopefully I am on the right track.
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Old 02-11-2015, 12:26 AM   #12
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From Panel to Attic Junction through 1 1/2 Conduit


If your running a 240v setup, you don't "have" to run a neutral for each hot. But you'll need to learn about and understand multi wire branch circuits or MWBCs.
In a nutshell you can run one neutral matched up to 2 hots from different legs.
But there's more to it.
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Old 02-11-2015, 12:58 AM   #13
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Yea dont know that much about residential wiring techniques but have done some. I work in commercial and industrial mostly. Used to dealing with BRB BOY. Romex throws me off sometimes. Does multiwire in residential work on the same principles as commercial without the extra phase?
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Old 02-11-2015, 02:36 AM   #14
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Originally Posted by clw1963 View Post
If your running a 240v setup, you don't "have" to run a neutral for each hot. But you'll need to learn about and understand multi wire branch circuits or MWBCs.
In a nutshell you can run one neutral matched up to 2 hots from different legs.
But there's more to it.
Thanks for your input.

My assumption was that since I was having to use ARC Fault breakers on these I had to run the neutral back since it monitors the entire hot and neutral circuits.

If I remember correctly, I'd need to use a 2 pole (or paired double 1 pole) breaker, which Cutler Hammer does make for my BR type breakers, but I don't think they have an ARC Fault 2 pole. I am using 1 pole 20 Amp ARC Fault breakers.

I realize they are more complex, at least for me, and the only area I could really think it would benefit (vs complexity, etc) me is in running a line to under the sink and splitting an outlet between the dishwasher and disposal.

However, personally it just seems easier to run a single dedicated 20amp line to an GFCI outlet that services both needs.

I guess it might help too for splitting the kitchen counter outlets, but I'd rather keep it simple in my own mind as to 1b\1w\1g=1 breaker.
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Old 02-11-2015, 02:44 AM   #15
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Stay away from mwbcs. One trips they both go out. You lose two circuits.Plus what you mentioned.

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