#1 DIY Electric Mistake - Can you use Romex Wire in Conduit?
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- čas přidán 30. 03. 2024
- Can you run Romex or NM cable inside of Conduit? The most debated question in DIY electric wire work. Learn the truth about this highly misunderstood mystery.
Conduit Fill Calculator: www.southwire.com/calculator-...
NEC Code Info:
Conduit: up.codes/s/nonmetallic-sheath...
Damp Locations: hew.com/specifications/70555.pdf
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Disclaimer:
Due to factors beyond the control of Silver Cymbal, I cannot guarantee against improper use or unauthorized modifications of this information. Silver Cymbal assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Use this information at your own risk. Silver Cymbal recommends safe practices when working on machines and or with tools seen or implied in this video. Due to factors beyond the control of Silver Cymbal, no information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or from the information contained in this video is the sole responsibility of the user and not Silver Cymbal.
Can You Use Romex in Conduit Legally? STOP Doing this Wrong - Jak na to + styl
What do you think? NM Code Info: bit.ly/3VCAm7R Damp Location Guide: bit.ly/3VL75rX - My Amazon top tool pics: www.amazon.com/shop/silvercymbal
I love your content. I would have liked code article from 2020 and 2023 code cycles. I'm not an electician so I dont fully understand everything about electrical or code. But did you consider heat build up? I know thats a thing. Because the wires are jacketed they are rated at a certain amperage and temperature. As the heat builds, so does the resistance, and as the resistance rises so does the heat. I've been told that is a runaway senario, which is why we derate wire fill. Is there a connection between that and electricans being almost unanimously against putting romex in conduit? You would be putting a rated, jacketted product into another jacket which increases heat?
@@MarbleGoblin Hi there great points, I added links above. Thanks!
I read the codes but those are Texas codes and not NEC. Texas codes are cool. But it doesn't really matter either way. I always thought you should be able to run sheathed cable in conduit as long as it didn't fill the conduit over 40%. I retired 12 years ago. Back then the inspectors wouldn't let you do that.
I've considered all of these things over the years and done some of them. What I am disappointed in is you. You probably know when and where and how to run a little Romex in a conduit, but you never gave one example of when, where, and how _you_ do it. Thumbs down.
Honestly, this sends shivers down my back. Happy therefore to say that this side of the pond it is a non-issue since we can't even buy that type of wire here. For outside and underground use we have metal shielded cable, inside it is all single wires running through PVC conduit, meaning you don't have to take down the walls to change the wiring. With respect to the amount of wires running through the conduit there is only one (strict) rule: it may never ever carry wires from more than one fuse. In practice this means that inhouse the vast majority of conduits contain just three 20A rated "THHN" wires (ground, zero and fase) however they may be accompanied by one or more 10A rated wires for switching lights.
Thank God! Someone who got TO THE POINT and didn’t yammer on and on for 20 minutes!
100% True that!
but it was completely lacking in inane dad-jokes
how can i drink coffee without them?
And he didn't advertise a sponsor 😅
God yes! I'm tired of half hour videos saying something that could be said in 5 minutes or less. Even if the subject is interesting who has the time? Save the long vids for something that requires depth and intricacy. We'd all do better, learn more, and see more creator's work.
Right?
I love how this was a short, informative, accurate video that wasn't stretched out into 20 minutes. I wouldn't of watched it then. I like smart people.
I really appreciate that thank you
Yup. It’s content like this that brings me to CZcams first. I didn’t have to spend 10 minutes weeding through SEO blog spam before finding the answer.
Thanks!
I agree. Great pace. Good info.
"wouldn't have", not "wouldn't of". Where did you go to school?
@@banjohappy I was kinda excited because I knew I worded that wrong. Then I realized youre just a dick and aren't correcting me to teach me. You corrected me to feel smug about youself. I bet your mommy is so proud!
A couple of minor nitpicks: You can run NM cable inside conduit in a damp location _as long as the NM cable is rated for damp locations_ (i.e. it needs to be NM-C). Basically, conduit vs not conduit has nothing to do with it. You can only run anything in a damp location if it's rated for damp locations (which ordinary NM cable isn't, but some other kinds are).
Also, technically, the wires inside NM cable are just THHN, and have exactly the same insulation/protection that individual THHN wires do. The only problem is that the manufacturer has not explicitly _stated_ that they can be used in that way, so even though there is actually nothing inherently unsafe about doing that, the code just doesn't allow using things contrary to the manufacturer's instructions, so you can't do it, really because of a technicality in how things are written. It's not that it actually wouldn't work fine, though. It's more a letter-of-the-law thing.
Thank you, that is exactly the simple answer we all needed about how to run which type of wire, in a conduit in a damp location.
Thanks for that, and since the wire is not printed THHN on it, if you use it and something goes awry, the insurance company will have their say in it as well.
I'm reminded of when I used a PVC pressure coupling in a drain line. Failed inspection because DWV wasn't printed on the coupling. Had to use a fernco rubber coupling... letter of the law should be superseded by intent.
@@jon__doe
Unfortunately, that's not how The Law is usually interpreted, which is why they need lawyers and sh** gets so f***ed up.
_"Well, for someone who has nothing nice to say about lawyers, you certainly have enough of them around."_
_"They're like nuclear warheads. They have theirs, so I have mine. Once you use 'em, they fuck up everything."_
_- "Other People's Money" -_
Had a situation recently, where inspector made us run (2) 12/2G UF's in 3/4" PVC conduit under the slab (previously installed before slab pour) to an island in the kitchen. Boss should have argued that under slab inside the house is not damp location. That's UF 40' from panel thru attic to nearby wall, down the wall and 15' over to the island. Twice.
All info and no background rock concert! Excellent!
Good observation. I was wondering why this was so pleasant to watch. Also, it was really well presented and extremely informative. I agree - it is excellent.
Once in a while you get a YT creator with some common sense.
And no clown act by the presenter.
The same 4 people above 20+ years ago probably would've complained that such a simple video with no rock concert in the background was "boring" and meant only for old people. Some things never change, especially when it comes to consumers being picky about the content they absorb, depending on their moods and peer group opinions. Just saying🤠
Good vid and most important, accurate. Fun fact, back in the day the company I worked for, due to a conflict with an inspector, actually contacted one of the bigger wire manufacturers and asked what type of insulation they used on the wire they put in NM cable and they said it was thhn. Also, I've in the past have pulled the conductors out of the jacket and noticed that on the conductors insulation had lettering and upon looking much closer, it read that it was thhn /thwn. Therfore I wasn't hesitant about using them for any conduit application, even in a wet location. But I've also done that and there was no lettering on the insulation therefore being hesitant to use it in a wet location but not so much in a dry location.
I could have sworn I remember working a Friday evening trying to do a last 25 ft run of wire for some track lighting and was short on wire so I grabbed the Romex saw it said thhn and told my foreman lets just run the Romex without the jacket, it be the most expensive 25 ft run ever but screw it at least we'll be done, and we did so ya I even remember cutting some power cables that were 14 gauge thhn to use as pigtails when I was stationed in Afghanistan.
Yeah, the wire inside NM cable is just THHN, so technically it's no different from using any other THHN. The problem, though, is that the manufacturer simply hasn't certified it for use in that way, so technically you're using it contrary to the manufacturer's instructions, which is a violation of the code, regardless of what type of wire it actually is.
Basically, there's nothing inherently unsafe about doing it (provided you were careful about how you cut it out of the sheath, which is another potential concern), but it's just against code due to a technicality in how things are written (so _technically_ you still shouldn't be doing it).
(However, if the wires have the correct markings on them, then I seriously doubt anybody would be able to _tell_ that's what you did anyway, so...)
The question/problem isn't the material of the wire insulation, its the thickness of the insulation. Its thin and prone to shorting in romex.
You seem to thing its all about the material. I kinda asking you , because i don't very veyr novice@@nowmann2821
You say technically there is no difference , but there could be a difference. Its not to code, so something must be different. I'd love to know why.
maybe its too thin , maybe its cured differently. maybe its harder or softer. Again ,. someone is saying there is a difference. @@foogod4237
I've never seen lettering on the individual conductors inside NM. I wish they had it
Thanks for settling this debate. I appreciate that you got right to the point & kept things moving. I appreciate your editing time. I’m guessing other viewers do too. Great job.
Wow, I have seen this topic bandied about on YT dozens of times. Never have I seen it so perfectly answered as here. Thank you!
No topic brings out the internet electricians like NM in conduit. 😂
Master Internet Electricians
As long as it's(N)ot (M)y conduit.
Pick a side , war is a foot
Carful @@billted3323, you'll offend the EU electricians. They don't like our fractions.=
I R a professional 😂
If it's not compliant in your jurisdiction you can always run the NM romex cable to a metal j-box then splice in the box and run conduit out with rated individual conductors. As I understand it there are special circumstances such as foundation wall drops (not framed) where it's permitted (with limitations) but generally frowned upon because of the possibility of overpacking/lack of free air and heat dissipation with all of the extra sheathing, but conduits are not the only place where overpacking is regulated, such as cable trays in commercial applications where you also have to follow a strict packing density with spacing. Generally and practically speaking difficult for me to understand how a single NM drop in a conduit is going to overheat relative to the myriad of NM cables most homes have in their attic bundled with insulation in the dead of summer, seems relative.
Great video covering this topic though.
dude thank you for keep it straight to the point and facts only. Cant stand videos where they go into a main character back story arch.
Great video and very valid points. I would like to add something. Another reason that you can not pull the individual wires out of the NM cable and pull it through the conduit is because the wires are no longer labeled on the insulation like THHN, THWN, THWN-2 ( Voltage, gauge etc)
A good explanation without commercials !
Thanks. I run individual wires in conduit, and often leave room for extra runs. The inspector flipped out when I ran a two inch and an inch and a half conduit sixty feet from the house to the garage. When I bought an electric car, I was mighty glad that I could run an extra 50 amp circuit.
I always run a extra wire from the switch box to the light fixture just in case if later on they want a ceiling fan.so they could be switch separately
More expensive, but just smart for future upgrades, especially if you plan to stay in that home for the long run.
Do you upsize your initial wires to account for the de-rating with the additional conductor?
@@ronnietruman7296 Not sure what your asking. Any additional wires pulled through the conduit at a later date would be separate circuits and fused separately according to wire size.
@@twigd3825 I refurbished a 1945 house with all new wiring and I put in the three wires with ground plus fan rated boxes for ceiling lights so there is no issue if next owner wants a fan.
I decided to learn how to bend EMT correctly and just bought spools of THHN to do all of my shop lighting. It was a frustrating but rewarding experience. Untold numbers of bad bends I had to cut out and redo, but I did it.
Congrats! Not sure how you are learning, but if you don't have the handbook written by a guy named Benfield, I highly suggest it. It's an old illustrated guide to using the Benfield conduit bender. 1940s maybe. It's pretty easy to follow with amazing results. Happy bending!!
Good of you to take on the challenge of bending conduit.
When I was in school to get my journeyman electrician license, I did a 3 month co-op at a Wal-Mart that was being constructed near my home.
I was trying to run conduit for the rows of walk-in coolers in the back of the store.
Every time I bent a piece wrong, I tossed it in between the cooler and the wall of the building.
One of these days, someone is going to discover the pile of bent pipe hidden there and wonder what in the world was happening to the electrician that was wasting all of that pipe.
I eventually became very efficient at running conduit, but I'll always laugh about those early days.
Or you could use the new type of bx.
Just bought a new house, was fixing a bad gfci outlet today that supplies power to an outdoor refrigerator, while replacing the outlet noticed they used romex. And boom this video pops up.
Thank you, I’m going to be looking now to fix that too. Your videos are great, keep doing what you do.
Great summary! Thank you. I now know that I've definitely not followed code on that issue for a couple of non-permitted outdoor connections. (Properly done otherwise.) This makes it clear that they need to be removed or permitted and redone if I ever sell.
I love your videos and your great delivery.
I understand electrical code does clearly rule it out. Southwire is the parent company of Romex. If you look at their conduit fill calculator - NM wire is not a selectable choice. In fact - have been unable to find any conduit fill chart that shows NM wire. I also cannot find where any wire manufacturer (or Intertek ETL or UL) states that it is tested and permissible.
If you compare the price THHN wire to NM wire, you will certainly use THHN (or similar) inside the conduit.
I live in the US mid south where we have rapid temperature change and usually high humidity. Condensation often occurs inside metal conduit located in vented attics and garages.
The only situations where I would use NM inside a conduit is 1) where I need nail protection within a column or 2) when I need to span an space (like between two cabinets). In these instances I would only run a single NM wire.
I agree the brief no long dialogue is appreciated
You cleared this up very well! In the factory I always pulled THHN Wire in conduit to the fill specified in the NEC Code. Thank You for this Video .
I wish everyone’s instructional videos were as direct and to the point and as well organized as this one. Liked and subscribed and you should too.
Please elaborate. What was incorrect?
You are allowed to run UF-B (and other equivalents) outside and in Conduit. It is rated for direct burial in no conduit. Want more protection - Conduit is allowed.
It is a 'romex' style - but really is a hard flexible plastic surrounding all the wires. So no paper, and no water leakage into any conductor.
This. In fact, if you're running cable in conduit outdoors, it MUST be type UF. This is because the conduit cannot be considered to be free from moisture, so NM is NOT allowed.
@@edtompkins865 hmm then why did the sparkies that ran feed under the driveway at our complex use thwn? If UF is that is allowed, they would have run it
@@harveylong5878buried raceways are considered wet environment so the conductors ran in them must be rated for wet environment (ie "w" in thwn). UF is actually rated for direct bury itself so no conduit is required.
You absolutely nailed the code. Well done!!
Thanks for making it very clear and explaining the pros and cons of using the Romex inside a conduit. As a DIY'er I find it very useful to get sound explanations about many code-related issues which may be contradictory to common sense but it is there for a good safety reason and/or good practices.
Straight to the point, loaded with information. The world needs more videos like this.
I knew 90%, but think I'm the exception. Learned 10% (didn't know you couldn't pull the wire out of romex and use it). Only took 3 minutes. Excellent job!
Well as long as you didn't use those conductors you pulled out of its sheathing inside a conduit, then you should be fine.
This was a great, quick, yet appropriately detailed answer to an interesting question. Appreciate it!
Great explaination. Very concise. I like short videos with lots of info. I must say, as a DIY, I've likely violated this but conduit is seldom used in DIY.
Great video, sure do like the style, right to the point. Thanks and Cheers!
Excellent and to the point. I thought part of the romex-inside-conduit issue was that of heat buildup (which is probably why the 53% max fill was designated.) I also appreciate you telling us that individual wires from romex bundles are not allowed. I would have thought otherwise. Keep up the good work.
The fill ratio has more to do with NFPA regulations than anything else, along with mitigation of unintended damage and destruction of your own work.
When you're pulling cable or individual conductors over significant distances, what you're pulling is going to be rubbing up against anything else inside that conduit, causing large amounts of friction, which generates heat. This can, will, and has damaged cables halfway through the run to the point that a fire hazard is created in an non-visible area by way of burning through any and all insulation.
Cable pulling lubricant does mitigate this somewhat, however the code on this primarily exists to address this issue.
So romex in conduit in an 120F attic? Electrical advice should be left to licensed electricians.
@@mongo7129 I am one.
Obviously, the NEC and NFPA should be consulted prior to starting work on any installation.
That being said, there is no reason to be using romex in that application in the first place, and if you did, you're getting fired.
@@RighteousJ Homeowners aren't going to reference the NEC and NFPA, thats why they're watching a stupid youtube video! There in no application where you have to run NM in a conduit...none. Running romex in conduit is like burring the american flag... can you yes...should you no!
@@mongo7129 Agreed. That being said, the electrical code exists for a reason, and the main skill you need to be a licensed electrician is to know how to navigate the NFPA in the first place. That's literally how you pass the written exam - answering a selection of code-related questions in a set amount of time, while having the actual book as your sole reference. Beyond that, you're expected to apply that skill on every job going forward.
Being a skilled tradesman can best be explained as performing professional guesswork based on incomplete data provided by those of questionable knowledge. Ultimately, the person doing the installation owns any hazards that result from improper work, and if something I'm being told to do by management doesn't line up with the NFPA, it's my obligation as a professional to refuse to perform the work as described.
As far as these sorts of videos are concerned, however: if work was done not to code, regardless of whether or not a permit was pulled or a "professional" did it, then insurance won't pay out. There's a saying in my business: if you think it costs a lot to hire a licensed and qualified electrician, try hiring an unlicensed and unqualified one. This absolutely encompasses hiring yourself if you don't know what you're doing but refuse to admit it.
I love the straightforward information you provide.
Great format! Direct and to the point. Thank you!
This is great information. We run into this situation at campgrounds when owners are burying NW wire
From the pedestal (18” above ground to “24 below ground) in conduit. Never thought it was an issue for this short span of wiring. Of course nobody is dismantling the conduit to check.
Mostly likely they are burying "UF" which is intended and allowed for direct burial. It will be gray, and instead of an outer sleeve with separate wires running thru it, the outer layer is a solid mass molded around the separate internal wires. The internal use has paper or string inside the outer sleeve to help maintain its form, but the outdoor doesn't need that because it is solid.
Also the short length of conduit falls into a separate category - conduit used as a short protective sleeve rather than for the entire length.
@@Sylvan_dB So it’s ok to put UF wiring conduit outside?
@@Coldpack13 A short sleeve as you described to protect the vulnerable cabl between the ground and the box is fine.
(I don't know of a national definition for "short" but usually a foot or few is fine... a local code might be more specific)
@@Sylvan_dB Ok, thanks for the reply.
@@Coldpack13 Yes, UF is rated for direct burial, and by extension damp or wet locations. UF is allowed in conduits as long as it does not exceed the capacity of the conduit. It is a common practice to use a conduit to protect the UF cable between the box and the soil to give it extra protection, like in the video. For example, if you want to wire a GFI on your shed, it's common to bury UF cable and install PVC conduit between the box and the ground to protect it from sunlight and physical damage, like weed wackers. UF is even harder to pull through a conduit than regular NM cable is.
Great video. Right to the point and very informative. Subscribed.
Yes I did find it interesting. Ive run single strand but always wondered about this. You covered it well and concise. One thing I imagined is if there would be overheating issues. Since you don't mention I'm guessing not.
❤ Very well done presentation and excellent explanation.
NEC and CEC I’m sure would be appreciative of your clear instruction.
Thank you
For some reasons these types of videos have been showing up on my feed. So far this one has been the most to code accurate. The only thing I'll add, that you did or did not talk about. Those outdoor disconnects with a whip going to something like an ac condenser unit. There box is pressed out to have raised feet. So whether you run direct romex or sleeve it through some type of conduit, some people might consider that a damp location.
When I see a video from this guy, it’s a must watch. Always good information presented clearly without dragging it out!! I got a lot of understanding from this video!
I really appreciate the nice words, thank you
The Ones you don't get a comment from are in Closed Caskets
Brief and to the point.
Clear and concise.
Thank you for nailing this. 100% correct, getting all the corners of the code that "CZcams comments experts" don't actually know.
You are absolutely correct. I’ve seen lots of CZcams videos with people using NM in their sheds and running it in pvc conduit. What a total waste of money. Most of the time, they just slop in the pvc, kink it, and do not use the correct fittings. Oh, white pvc is not pvc conduit.
So in this situation, how do you get power (underground) out to the shed? I assume it has to go inside some type of conduit. Is this where the THHN inside conduit is used? (Wondering, as my electrician is planning on using NM inside PVC and I want to verify code compliance.)
@@lances4803 NM inside pvc is not legal underground. Reason: PVC underground is a wet location. Best way, pvc and THHN/THWN. THWN the W stands for “wet”. If pvc is chosen, you can run “UF” cable in it. Looks similar to NM, but Wet rated. Second Best: Get a cable rated for direct burial and use pvc at the locations where it comes up from the trench. Personally, I would use conduit all the way, panel to panel.
Some other things to watch for. At the shed, if feeder and panel, you must have a disconnecting means at or near where the conductors enter the shed. Normal to use main breaker panel. Breaker can be oversized with no issue as it is disconnect, not overcurrent. You must have grounding electrode connected to ground bar in the panel. IE, two ground rods. Ground and neutral must be seperated. All receptacles must be GFCI protected. Best wishes! Kevin
This is exactly what I did about 19 years ago when I knew even less than I do now. I believe the Romex was rated for direct burial, but I put it into PVC pipe. I used the PVC for protection more than anything. I have witnessed a few too many shovel incidents and rodents damaging insulation and thus allowed the wire to corrode away. Also, I've been involved in a small number of detached garage electrical issues where one of the 2 phases was lost, which had to be due to one of the wires getting damaged.
With how wet the ground is around here, I did not understand why adding about $10 (in today's dollars) in PVC was going to harm anything.
I also ran some Cat 5 cable to the shed at the same time, ran through a separate PVC pipe.
The ground is a lot of clay and holds a lot of water around here. Both the cat 5 and Romex seem to be doing their job perfectly yet. I recently moved the shed about 5 feet and had to deal with the wiring. The Cat 5 still gave me 100 megabit. I have no idea if that cat 5 was ever meant to be used in wet locations. I never checked, and I didn't know how to check 19 years ago.
@@KevinCoop1 Thanks Kevin, much appreciated. Keeping this for future reference!
I saw someone with I think 6-3 Romex maybe some sort of thicker SER run through PVC drain pipe instead of conduit. Not sure if it's against code to use plumbing pvc instead of conduit but it looked pretty ghetto. And there are obviously no proper fittings to connect to panels and junction boxes.
Howdy. Yeah.
Running several Romex's in a conduit one should check the current derating coefficients due to derated cooling. One may need to choose the next lower AVG (thicker wire) for the Romex's to handle the breaker current rating.
Regards.
Nice informative and to the point video. My home had 2 outlets installed on the back of the fireplace that extends in to the kitchen. Whoever installed them removed the sheathing where the wires came down from the attic and ran them through a thin, WT looking plastic conduit that had glue in a few spots to hold it against the brick although the receptacle was screwed in, but the wall plate would come off when unplugging an item lol. I had an electrician install a metal conduit that is bolted to the bricks, but I don't know if the wire was replaced. The company sent a few workers since I had a few things that needed to be addressed.
Yes, this helped. The best previous answer I got was "sometimes". -- Thanks for the effort to upload. ---
Every builder, inspector and journeyman electrician should have this on a test. There should be a book other than the electrical code book for common things like this because there are too many codes that for many builders, they will never run into, but clutter the simple/critical things like this. I owned over 100 homes and actually had an electrical issue with 220 30 amp circuit had romex in a metal conduit. Moisture was retained and shorted circuit.
When I became a Master Plumber in TX, I was tested on actual working plumbing principles, not plumbing code. You roughed in and topped out little miniature two-story houses, you had to cut and fit pipe with math formulas, work cast iron pipe, correctly adjust water heater flames and a lot of other shop stuff. Then you had a long written test of plumbing theory, not code. Then I move out west and it's all about vomiting up plumbing code for your tests. Your shop experience came from working for your father or uncle and them lying about your actual work experience. What a system and what lousy plumbers overall.
When I did my C of Q, there were quite a few questions not related to the Code book. Basically a pick the best answer question regarding general knowledge. Did not have this in particular though. Those are tricky questions because multiple questions were correct but it asked for the "more correct". The wording was a bit confusing too.
I would not do this anyway but I rarely use Romex.
I have seen people put AC90 in a conduit though lol.
How does anyone "own over 100 homes" ?
@@mattywho8485 either house flipper or a landlord
@@mattywho8485 I had a 95% minimum occupancy... It is easier the more houses you have if you stay on top of it.
A couple of things. One. A very important point is romex can't be used in damp locations due to paper insulation which wicks in water. You can see @ 2:12
Two. Romex Does use THHN wires. Those wires are allowed in damp locations. Romes need to be brought in a j-box, to be de-sheath then the rest of the wires can be used in a damp location in a pipe.
Cheers!
Finally some information that really makes sense - the paper insulation. Now I'm in Europe and paper insulation on electrical wires isn't present and the ground wire has the same insulation as the other wires and is color coded yellow/green.
Conduit is by itself not bad, and is preferred to protect against rodents.
The individual conductors from Romex is vinyl like in THHN, and derated based on the 90 deg column like THHN, but It lacks that clear nylon outer coating that THHN usually comes with. Without a listing from the manufacturer I can definitely see an inspector still flagging you for stripping the outer jacket and pulling the individual conductors in an exterior conduit located in a damp location.
@@BluCappy419 I got this from the manufacture
What is Romex Wire?
Romex wire is made out of two or three THHN wires combined with a grounding bare copper wire. Like the THHN wires, Romex wire can’t be used outside because of its minimal PVC jacket protection. However, these wires come in larger sizes than the thinner THHN wires; 14/2 and 6/3 are used widely as electrical wire, despite the fact that it can’t be used in conduit at all. The primary use for this type of wire is to run more than one conductor at a time through a separate grounding wire.
@@stevedonovan22 What did all the other manufacturers of NM-cable say? Romex is just one of many. And quite frankly, in my parts, is not even seen very much any more.
XHHW...the W stands for Moisture Resistant...do yourself a favor.
Excellent explanation. Now I know why putting romex in a conduit is a mistake. Thanks for posting.
I agree with others! Less than 4 minutes and I understand exactly what the point is. That's why I subscribed. Thanks!
Great coverage, you anticipated all my questions!
Glad it was helpful!
No wonder the water won't run these pipes are all clogged up with the wire
This house sure gone crazy!
@@allkindsofoutdooractivities That's a classic!
The three stooges proved that
@@mistervacation23 😂😂 one of my favorite shorts!!
Great video. I actually ran Romeo through a PVC pipe to my shed…what a PIA. I need to change out those wires for THHN wires. Thanks for the info.
Thank you for concisely covering a topic with minimal yadda yadda. It's refreshing. And you bring up a big point, often missed: If it is technically correct, but not recommended by the manufacturer, it's likely not going to be allowed in the NEC.
I've used Romex in conduit in an off-grid remote location to protect it from mice, badgers and squirrels. But I also used 3/4" pipe so it pulled quite easily.
The only time you should really use NM cable inside a conduit is on the basement concrete wall. You can use conduit as a sleeve of protection when you drop the NM cable down from the basement ceiling joists onto the wall to install a metal switch/outlet box. Fasten the conduit to the box with an appropriate fitting, then install a plastic bushing on the other end and fasten that end to the ceiling joist using a one-hole conduit strap.
I agree, it’s to protect the exposed Romex from being damaged.
OK for UF (Direct burial using PVC conduct for protection for outdoor use. Metal conduit below ground is not acceptable because of corrosition
Thank you, came in to point that out. Sleeving cables for protection is definitely allowed.
Came here to say just this, have done this for a dryer outlet and for a receptacle for the washing machine
@@pld8993 NEC 358.10 (2023) "EMT is NOT permitted to enclose underground conductors"
I hope you aren't a electrician!
While IMC & Rigid is permitted with "corrosion protection", It doesn't last forever, just a lot longer than EMT would.
Thank you for the short clear video!
There is also concern about heat dissipation when running NM in conduit, if you bundle more than I think 3 current carrying conductors together for more then some length, you should be de-rating. However with 1/2 conduit and NM cable, you will hit conduit fill before that's an issue. I use EMT for vertical runs from the ceiling to electrical wall boxes in basements. Any other place I would need conduit, I will run THHN. Pulling NM around any kind of bend would be a nightmare!
Fantastic information extremely well presented! Thank you.
Just starting to re wire my sisters basement (1969 house) and have to replace the aluminum wire feeding the garage (underground). This confirms what I already knew. You always seem to time it right thank you. Always enjoy your videos.
I battled with a contractor on this recently. He ran NM for a mini split right through a block wall and then wrapped under and in to a disconnect. Unacceptable to me having both unprotected NM passing through rough concrete holes and NM pinched behind a disconnect outdoors. Had him junction it indoors to conduit and THWN out to the disconnect. He insisted there was nothing wrong with what he had done but ultimately installed it the way I asked.
All the multi-family new construction here in the PNW has Romex in the outdoor conduit going from the disconnect to the outdoor unit. I do HVAC and asked an electrician about it, I was informed that the inspectors walk up to a building and see 40 something mini-splits and just sign off on it because they don’t want to inspect them all.
I agree that inspectors might not check, but that doesn’t make it right. Conduit is not guaranteed to be watertight, and neither is NMC. That’s why damp locations are not a good idea.
Code regulations are there for many reasons. While some reasons may be lost in antiquity or controversial, they made sense to someone at some time.
Humans are very likely to come to poor conclusions individually, which is why groups of experienced reviewers come to consensus on codes. “It won’t be checked” and “everybody does it” are not good excuses.
@@joelperigo7213 Isn't it legal if it just goes to the disconnect mounted on the outside of a wall? From what I was reading NEC approves that every house I ever seen had AC unit used NM wire usually 8/2 to a disconnect. 99% of the homes here in AZ are big units not mini-splits usually 4-5 tons. My home has roof top unit like 99% of homes built before 1990 all of them are using NM wire up through the attic to a disconnect mounted on the stand below the unit. The roof top units are like what most are used to seeing on commercial buildings entire AC unit is in one box. The air is ducted up to the roof makes replacing them simple. Newer homes have split systems big condenser unit on the ground like most other states. Those I see disconnect is mounted to the wall with NM wire passing through the wall.
@@Mike-01234 From what I read, similar debate there to what is discussed in this video. NM is straight through the wall and direct in to the back of the disconnect without passing much daylight seems to be common but might not meet code. In my case, the NM ran unprotected through a block wall, wrapped down and in to the box (3” run behind the box), AND was mounted on a stone facade so not right against a wall. Worse than what may commonly be done, in my opinion.
In the situations I am finding, the NM cable is not just coming out of the wall and going to the disconnect, it is also going through the liquid tight conduit from the disconnect to the outdoor unit. Because this conduit is outside, the interior of the conduit is considered a damp location, and as such, NM cable should never be used in it. I agree that this is not correct, and I am not justifying it. When the company I work for does HVAC installs, we contract out the electrical to a quality company that pulls the proper wire. The problem is with the large companies that do the large multifamily, new constructions, and the lazy inspectors that don’t want to do their job. I am not saying all inspectors are lazy, but I have seen a lot that are lazy, or start questioning me, an HVAC service technician, on if the electrician did their job properly and if a certain disconnect is legal or not.
The quality of this video is why I subbed.
Nice video! Thanks for the straightforward explanation.
Very helpful.Thanks.
Fantastic video thank you
Great video. Informative, thorough, and to the point.
I think you did a great job on this factual and concise video. Since you did make a comparison between NM and THHN, It's worth noting that the ampacity of NM-B is determined by its 60 degree C rating. While THHN has has a 90 degree C rating and its ampacity is determined by the lower of the wire rating or the temperature rating of the terminations.
Also worth mentioning that wire pulling gel is super helpful when running Romex through conduit.
Rookies always overlook lube.
My electrician ran some 10/3 romex through 3/4" flexible metal conduit for a portion of the run for some added protection where it wasn't going to be covered up by drywall. The inspector had no issues with it at all. I think the main issue is when people who aren't electricians try running romex in conduit for long runs because they don't know what THHN wire is.
True about DIY'ers who run indoor rated Romex outside in what they think is water tight conduit mostly water tight flex conduit. THHN has to be rated TWHN which means rated for wet environments. Most if not all THHN is rated also for TWHN it's marked right on the wire. NM Romex rated for wet environments is lot more expensive. Most electricians don't like stranded wire since NM Romex is solid wire easier to terminate.
Great video, unfortunately it doesn't apply here in the UK. I do like your style, I hope you go far.
Liked and subscribed. I enjoyed your delivery and clear educational approach.
in the chicago area we are required to run all wires in conduit. people who have never lived anywhere else think its crazy you can just run romex through studs in other states.
Chicago is crazy with that. Think of how many millions of dollars are wasted by being overly paranoid about NM run bare. The majority of electrical fires (besides extension cords/devices plugged in) happen at the terminations/junctions, not over the length of the unbroken cable itself. We could probably save some houses from flood damage if every water pipe was required to be sheathed in a larger pipe to catch any leaks, but sometimes good enough is enough.
You can thank organized crime aka unions for that. It isn't about safety but about limiting who has skills to run conduit. Any kid can drill holes and pull "Romex" to boxes. But to run EMT or even MC takes more skill that are usually kept to union electrician training.
I believe you can use mc/ac cable in the city of Chicago but there is a limit of 25 feet per run
@@vicktorpatriot1430 Yep, and don't forget billable hours for those union members. Pulling a run of NM from a panel takes a few minutes once the holes are drilled. Cutting conduit, doing any custom bends, then pulling conductors, etc. will take many multiples of that time. And that's in new construction - adding to a circuit with finished walls is now a huge project with conduit $$
I usually attach the Romex to the metal conduit and energize everything. Takes the guess work out of stuff.
Hey it's all metal, that's an extra conductor to use!
Bravo!
Best comment.
rofl
Thanks for a good to the point video answering questions about electrical installations i have certainly thought about about "doing".
I suggest making a quick video about the popular 20 amp /12 gauge wiring circuits being put in garages... how many folks install the said 20 amp circuit goods up to the individual boxes.. then use wall receptacles that are only rated for 15 amp draw for wiring joinery at the receptacle. {20 amp receptacles can be purchased for more $$ but few buy them}.
Thanks. After 8 months, I can finally start my small project.
The way I interpreted the code (30 years ago) is that romex, or nm is not allowed in conduit due to ambient temp. Wire in a sheath and then inside a conduit does not possess enough ambient air to properly cool the wire within. Therefor, I have never ran romex in conduit. Place a junction box and always transition from nm to thhn before entering conduit.
That doesn't really make sense. You can run romex in spray foam or other insulation. If your wire is getting hot it's overloaded.
Sooner or later, a circuit is going to be overloaded. It's inevitable. A breaker is designed to cut power when a circuit is drawing more amps than it is designed to, and has nothing to do with temp. If you are drawing more than a wire is capable, it's going to heat up. Only when the amps are higher than the breaker will it trip. If the wire is in a confined space(not just a couple of inches of spray foam) it has the potential to melt before the breaker trips. There is a degree of heat dispassionate must be allowed for.
@@jtsather4535 I disagree. You think conduit retains heat better than spray foam? Circuits done correctly are almost never overloaded especially dedicated circuits.
@@sparkyjerred419 That word "Almost" burns down houses. Take every precaution against that which can kill you. Even if it seems over the top. You might save a life.
Just for reference, I've been a sparky for 35 years.
You just need to grease the cables. Bacon grease works.
So glad I saw this because Im planning putting a subpanel in my shop building then running romex thru sched 40 pvc conduit. Ill research this even more . I want it to be right and safe. Thank you.
Easier to run THHN. Don't run romex.
@@ElectricianMagician That's the way the mill I worked in was wired. It was mostly 480 3 phase but there was 277 Florescent lights along with 110 lights. That's exactly the type wire they used in conduit. I have just a 220 submerged pump 4 '' well with 10 AWG and no 10 AwG ground supplying power to it. I was told since I was using halogen lighting in my shop the wire feeding pump from 30 Amp 220 would be sufficient to run to subpanel box to be put in , feeding from 100amp in service panel, 30 Amp would feed to well just like now
Prob have a dozen outlets but only one or two would be used at a time. Then a table saw unknown voltage and amps ( watts) possibly drill press and planer. One running only at a time. Also air compressor. It and pump will come on as necessary.
Wire feeding to sub panel is 10 AWG 2 COATED HOTS 10 AWG bare gr. I've got 200 Amp panel with 100 to house and 100 will feed shop.
That was very informative. Thank you!
Of course you can. As a very new and young apprentice I fell victim to the myth. I assumed that since romex was used in residential work and thhn was used in typical commercial pipe and wire jobs that romex wasn't allowed in conduit. It is kind of a logical train of thought but the conduit has no bearing on the use of romex.
So… nobody gonna ask about the black box casually hanging out at 0:35??
Traffic Signals in Southern California have Conduit runs from the Traffic Signal Controller Cabinet to a “pull box” near each Traffic Signal Pole. There generally two scenarios with the Signal wiring. The original scenario was to pull sufficient wires between the Traffic Signal Controller Cabinet and the Traffic Signal Poles, ie one for red, yellow, green, grounding etc. the second scenario was to pull “bundled cables” that are separated at pull boxes to each Signal pole. These bundled cables were introduced to provide a higher degree of protection from amongst other things, wire eating insects.
Excellent content. Will check out your channel and see if the rest is as good as this. Thank you.
Thanks 👍
What about running outdoor rated romex in a conduit outside?
There is NO reason to do that. It is MUCH easier just to buy wire and run that through the conduit.
You can just get Direct Burial Cable instead.
You nailed it. Very well explained video. Thanks
Glad it was helpful!
Very useful information! Thanks. 😊
I ran it underground to my garage 40 years ago in 3/4 pvc conduit and it still works.😉
Ideally UF (Direct burial Romex) in PVC conduit since it is approved. I don't believe standard Romex can be used because the plastic may breakdown over time when exposed to water & contaminates in water.
@@guytech7310- It's not really a plastics issue, (tho THWN is the right choice for underground installs) it's the paper-based protective wrapper inside the NM jacket can absorb, retain, and wick water the length of cable until it encounters a nicked wire jacket and shorts, or corrodes connectors. Yeah, more a problem in St. Petersburg or Seattle than Reno or Scottsdale, but rain happens!😢
@@KevinSmith-ys3mh Its the material as non UF Romex is not water rated. Look it up.
Now does anyone know why conduit fill is important? Hint heat
Very useful information...especially for a do-it-yourselfer like me!
Lots of info fast, thank you
The garage is considered a damp location in my area.
If in doubt, ask the inspector before doing it.
That's makes sense. Because in some areas, garages are not required to be heated. This can cause high humidity
Liveing in Arizona and SoCal, it wasn't a concern. Now after moveing to PNW between the Vancouvers, I've shopvacced and sqeegeed out a few garages after heavy storm winds blew water past the doors. Its also a favored location for sewer cleanouts, and fail prone/maint intensive utilities like water heaters, regulators, sprinkler trees, water softeners, and cars dripping from rain & snow. So, location matters- hence local codes vary!😉
There is the code and then there are insurance companies. I know of one company that made a living for a few years just rewiring many detached garages because the Insurance company demanded / required all visible romex to be replaced with conduit. Theory being if you could see it something is going to hit it.
Always check with your insurance company with renovations and to see if they will actually insure your wiring. Most insurance companies are draconian if they find something THEY don't like or is in their fine print. Denied claims are rampant in this day and age.
@@chrisd_man2156 If it meets code, the insurance company shouldn't make you do that. I'd get a different insurance company before going through that expense.
@@JohnD-JohnD Basically they make that same decision for you, when they notify you that your Policy has been terminated, effective immediately.
And BTW, in FL, CA, and a few other states once ONE insurance company terminates your policy,...THEY ALL DO,...because they have this service / registry now, where they all share information.
All can do is let people know of what is taking place out there. With over 51,000 electrical fires each and every year,...I'd say the "system" is sending a message to DIY types.
Your going to find out there are multiple agencies involved with residential construction these days,...and everyone needs to check with all of them. As many have found out the hard way,..."your responsibility" for NOT reading the fine print.
This is why I used to carry over 20 Million in liability, just for myself. And every job , and I mean every job, a permit was applied for, and inspected. NO freebies, no relatives, and especially no neighbors! LITIGATION IS IN FACT THAT BAD COMPARED WITH THE 70S'.
My understanding was that the jacket is not temp rated for any type of confinement but only for free air like in a house wall. Confining it should derate the ampacity of the romex.
Came in to see this comment as well, that's getting into the details and I knew it would not be covered by a short video. All in all, short spans for extra protection and not complete and closed runs will keep you within Code. It's actually a fairly complex subject... that is why someone invented Trade School and why watching numerous CZcams videos still doesn't get you a license.
Romex is already derated to 60C even when the THHN wires inside are rated higher.
@@dannelson6980 True but any further derating will stack. The absolute test is to read the conditions listed by the manufacturer when submitting NMC to the UL for testing. Short broken runs for protection purposes not applicable but complete conduit runs were very unlikely included in the original test conditions requested by the manufacturer. In short, NMC is not rated (nor are probably any cables) for conduits. Probably can be authorized by an AHJ but the derating could be unfeasible. In general, a multi conductor cable in a conduit is very problematic. Installation (required engineering formulas for installing cables in conduit may not even exist for multi conductor cables), conductor heating, moisture wicking, conduit fill.
@fritzmiller9792 In industrial locations such as biochemical plants, refineries and power plants, multi-conductor cables are installed in conduit ALL THE TIME. For protection, if protection is not required, cables trays suffice.
@@Fotosaurus56 I have installed many in cable trays and duct banks and through bond-outs and sleeved through short conduit but not power cables in conduits.... definitely signal and low power but never the power cable. I am sure it can be engineered with oversized conduit and other consideration but in general a cable is engineered to cool in a certain environment that a conduit won't allow for unless again it's oversized to the point of acting like a duct. Again, there is many complexities to this subject and there is no limit to the exceptions that often take place in unique industrial applications with engineers overseeing the installation and conditions.
A question I've been contemplating for the past couple months, as a client asked me if I could run underground power to his shed. I have seen people run NM through PVC and bury it in the ground in the past, but I didn't know personally whether that was correct to do. Now I know, thanks!
Good and to the point, useful video. Thanks!
All modern NM uses THHN-insulation on the two insulated conductors. Sometimes (depending upon the Mfg. of the NM) those individual conductors are marked, sometimes not. Either way, it is the same wire, and perfectly acceptable to strip the outer jacket from the NM and use it as individual conductors. It's literally the same wire.
I would challenge anyone to tell the difference between stripped NM, pulled into an EMT conduit, vs. individual conductors pulled in from a roll. I've had inspectors look at work done this way, and pass it without issue.
Lastly, using jacketed NM in any conduit is a classic rookie/DIY'er install mistake. While it is not prohibited by Code, it is extremely poor workmanship.
It is NOT the same wire. You can not strip the jacket of of any type of NM and use the individual conductors as the "Same." This is very misleading and outright deceptive and dangerous.
Unmarked wire is unknown wire, and needs to be discarded.
@@chrisd_man2156
Why? Why is it "dangerous"? And how is it different?
If the individual conductors are properly marked (as to size, type, manufacturer data, etc.) on their outer insulations, just as individual conductors pulled off of a roll, what's the difference?
Are you saying that the "Southwire" company (for example) makes two different types of conductors, one for spooling on to a roll, and a different one to put into NM or MC? That just wouldn't make economic sense, from a manufacturing perspective.
I'd veture to bet that YOU couldn't tell any difference, if you looked at two conduit-runs of wire, with one from a "roll" of THHN/THWN, and one from an NM or MC cable.
And what about MC cable? Can the individual conductors in an MC be removed from their metal sheath and pulled into an EMT conduit, for example? How would you (or anyone) know the difference?
Now... I'm not saying it's the best practice, nor is it very economical, but it's FAR from "dangerous", and will get one by in a pinch.
Lighten-up Francis...
I never use romex as a commercial electrician, but I do believe that the wire itself is THHN so it can go bare through a pipe etc (any place THNN can go). The conduit is the protection bro.
Exactly, the conduit IS the protection.
This is what I always understood to be true. So the bit about not removing the nm shell is just an issue with the mfr recommended use and not really a fire hazard?
I used to work in a wire mill that made both THHN and Romex from thick copper coils and barrels of plastic resins. THHN has one additional coating material added (makes it more resistant to the strains of conduit pulls) that is NOT included in the wires placed in Romex (because it's not required there and so would be too expensive to add), so, while nearly identical, they are not the same, and aren't intended to be run without the paper and outer sheathing
The wires in NM isn't *labeled* as THHN, so running it bare in conduit isn't code-compliant. You need the outer jacket, which has the listing...
@@blairmurri8741 So conduit doesn't cut it, but plastic and paper does? I don't see your logic. Also the N in THHN is the nylon jacket you speak of. Google "what type of wire is in romex"
Sounds like pretty solid advice.
Clear and concise! Thanks!
American electrical code is just nuts, that's what I think 😂
There is no country named America
Fucking mental. They can't even agree on a national one that actually enforced
It's pretty easy once you get the hang of it.
They have electrical code?
NFPA 70 otherwise known as the National Electric Code. You should have known,Lol.
Remember folks, no matter what you are doing, IF you are doing ANYTHING, you are breaking a code, a regulation, or a law. There are more than you will ever be able to comply with. Laying on the couch is the only way to avoid being a criminal in America, today.
Or yanno just learn what you're supposed to be doing and do it right...
That didnt stop the police from killing that dude who was asleep on his couch after a long night of work in February of 2022. Then trying to blame him saying he came after them with a hammer. So even laying on your couch is a crime
What the heck?
@@biasdahl4737 If an inspector wants to fail you, you will be failed. Read the code. There are more ways to fail you than there are ways to pass. 100% code compliance is not possible.
I found an under-ground old cloth covered Romex cable while digging for a garden on the side of our house when the ground started sparking. Surprisingly it did not blow the 15 Amp fuse. A previous owner had installed a receptacle on the corner of the raised deck that had been added after the house was built. Would have been nice if it had been placed in conduit for protection. I disconnected it at the source (attached garage) then ripped it all out.
What you said, plus the ambient temperature plays a heafty part. The load on the wire, the length and yes, the number of ninety degree bends, all play a part. If you pass thru a handi-box you always leave a service loop. You NEVER pull a bend on the wire at a sharp 90. It WILL heat up.
You have a nice video. Thanks for making it. With over 37 years in the electrical field, I can tell you, I've seen some dillies, that unknowing people have done. You can tell that the DIYer has never even heard of the NEC.
CZcams needs more videos like YOURS, to set the DIYers straight. THANK YOU!
So how do you get all those wires in a junction box with out a 90 degree bend? ( not a troll, I am really wondering)
@posatronic9262 the 90 degree thing is referring to longer runs from point A to point B. When it comes to the termination point, it's a little different in that typically the load on the circuit will be there, and the process of finishing the work at that location necessarily involves pushing excess cable/wire back into the box, thus causing the angle to decrease past the 90 degree threshold.
Never mind that this is part of the reason for leaving a service loop at the location you're pulling to; a service loop serves more purposes than just making maintenance and future modifications easier.