10/2 NM for general purpose receptacles

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nizak

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I came across a job that a homeowner started. It is new residential construction and he has roughed in all the general purpose receptacles with 10/2 NM.

Bedrooms, living room,hallways, foyer, great room, etc.

Since there is no 30 amp device that is suited for use in a residence ( 30A 125V twist lock and 30A 125 V RV are the only two I'm familiar with)is it code compliant to use 20A devices and put them on a 20 amp C/B?

12/2 NM for the lighting which is all going to be LED.

Total lighting load is going to be less than 600 watts.

14 switch boxes stuffed full of 12/2 and 12/3 cables.

What a waste of time and money.
 
Other than box fill , it's gonna be a real pain in the butt.
No code issues other than fill.
DIY yup.... what ya gonna do.
 
He is unable to finish the rough in and asked if I would be interested in doing it.

I wanted to pull out the #10 and simply start over. He's adamant about using it.


I guess it's not the most ridiculous thing Ive run into.

Some years ago I went to a residence that had burned. I was going to put together a proposal for a restoration firm to rewire the house.

Totally unbelievable. The entire house was wired in RMC.

I could not believe what I was seeing.

Come to find out, the house was built in the 40's and the owner did his own wiring.

He was an industrial electrician who worked at an chemical processing plant.

The work that was exposed in the basement was immaculate.

The insurance company ended up paying to have the pipe and boxes removed, and it redone with NM cable.
 
nizak said:
Since there is no 30 amp device that is suited for use in a residence ( 30A 125V twist lock and 30A 125 V RV are the only two I'm familiar with)is it code compliant to use 20A devices and put them on a 20 amp C/B?

What a waste of time and money.
Click to expand...

As long the recs are approved for #10- you're good- device listing is the mitigating factor here. Going to have to get 20a spec grades for this if connecting the 10 directly to the device.
It is going to be a pain when tucking in if you do it that way with that 10 solid..........so you might want to go ahead and push the stiff stuff to the back of the box the best you can and then pigtail stranded 12 out to the device- it will be much easier come push in time. And if you do the pigtail idea, you can use the cheaper recs that only go up to 12....
 
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nizak said:
I came across a job that a homeowner started. It is new residential construction and he has roughed in all the general purpose receptacles with 10/2 NM..
Click to expand...

nizak said:
He is unable to finish the rough in and asked if I would be interested in doing it.

I wanted to pull out the #10 and simply start over...
Click to expand...

I had missed earlier that this was of HO/DIY origins...

IMHO, ask yourself about the quality of the work/ code compliance that you have seen before you commit to anything- over engineering doesn't mean something was done correctly/safely. And if he will not agree to gutting any non compliant crap that he installed- then it may be walkin' time.

We hear about these all the time- some guy will (or attempt to) wire his house, only to call an electrician to "finish"- install panel/devices etc.
They do this to save $$$. CYB on this.
 
Just imagine how much trouble it will be to install devices w/ 10 AWG conductors, if the homeowner is adamant about keeping the 10/2 NM, let him finish it, not worth the headache to patch the mess.
 
nizak said:
I came across a job that a homeowner started. It is new residential construction and he has roughed in all the general purpose receptacles with 10/2 NM.

Bedrooms, living room,hallways, foyer, great room, etc.

Since there is no 30 amp device that is suited for use in a residence ( 30A 125V twist lock and 30A 125 V RV are the only two I'm familiar with)is it code compliant to use 20A devices and put them on a 20 amp C/B?

12/2 NM for the lighting which is all going to be LED.

Total lighting load is going to be less than 600 watts.

14 switch boxes stuffed full of 12/2 and 12/3 cables.

What a waste of time and money.
Click to expand...

Yes it is, tho as others have mentioned, watch box fill. and any boxes cut in to drywall might blow out when folding #10 back in them (lot of stiffness there).
 
user 100 said:
As long the recs are approved for #10- you're good- device listing is the mitigating factor here. Going to have to get 20a spec grades for this if connecting the 10 directly to the device.
It is going to be a pain when tucking in if you do it that way with that 10 solid..........so you might want to go ahead and push the stiff stuff to the back of the box the best you can and then pigtail stranded 12 out to the device- it will be much easier come push in time. And if you do the pigtail idea, you can use the cheaper recs that only go up to 12....
Click to expand...

Why does the OP have to use a 20A spec grade device?
 
edward said:
Why does the OP have to use a 20A spec grade device?
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B/C of this
VVVVVVV

GoldDigger said:
Presumably because the non-spec-grade is not listed for wire connections sized #10 or larger?

Sent from my XT1585 using Tapatalk
Click to expand...
:thumbsup:

Not all recs are listed to accept #10, contrary to the opinions of a lot of tradesmen. Many of the non spec cheap devices don't go larger than 12 per the listing.

To the OP: above I meant to say 15/20a spec grade device, not to imply that you must use a 20a device- one can use duplex 15's on a 20a ckt and be totally compliant.
 
For one in/one out you need a 17.5 cubic inch box. Most "cheap" one gang plastic boxes are 18 cubic inch.

Did you ask why he thought he needed 10 AWG? If he wanted "cheap" 14 AWG was sufficient for everything but SABC's, laundry, bath, and certain fixed appliances.
 
As I have said many times in the past, I am not an electrician, I am an electric motor guy participating in this forum because I like the theory and understanding the code aspects.

As a (gasp) DIYer, I totally 'get' what goes through someone's mind when they overbuild aspects of a design. When the 'cost of labor' drops to zero for a job (it doesn't really...) then you can allocate more money to higher quality materials. Then it is very easy to make the jump from 'higher quality' to 'bigger', missing the very real fact that you end up selecting a much more difficult to install materials.

Every receptacle that I install in my house is spec grade. Total overkill, I know. But spending $20 on a receptacle is easy to justify when I am not spending $200 on a repair call.

I have a strong preference for 'metallic wiring methods'. I use MC rather than NM. The cost difference is not that big, the labor difference is not that big...but I am sure that if I wanted a new house built and professionally wired using MC it would be a bear; it would slow the professionals down and tremendously raise the price.

When my kitchen gets re-done, it will be EMT in the basement to junction boxes, and then MC to each receptacle, permitting easy modification in the future. I'd need to import an electrician from Chicago if I wanted to hire that out at a reasonable price. But I like working with EMT...even though I often have to throw away bends because I did them wrong.

As others have said, just because one portion of the install was 'over designed' does not mean that the entire install is code compliant. Box fill issues come to mind, but there might be other issues such such as sizing of box fittings or support staples.

If the homeowner really wants the increased wire size, then IMHO you should up-sell corresponding materials for the rest of the job (eg. larger metallic boxes to deal with the additional stress of pushing in the heavier gauge wire, 'plug-tail' receptacles to make installation and repair easier, etc.)

Best of luck!
-Jon
 
I can agree with you about the stupidity of the HO. Makes no sense, but maybe he likes orange cable. :D Was he even aware of box fill? But I don't see it as a deal breaker assuming you can see everything and it's run properly. What I would do is change out all the boxes to steel, probably deep 1900 (or 4-11/16 if required) with a suitable mud ring. Pigtail the 10's with 12 for connection to the receptacles. Should have plenty of room.

-Hal
 
nizak said:
... a residence that had burned ... was wired in RMC.
The insurance company ended up paying to have the pipe and boxes removed, and it redone with NM cable.
Click to expand...
I'm surprised the pipe & boxes didn't survive the fire and enable the rework to be wire-only with THHN.
Ironic that the electrical system was enclosed in so much armor and yet there was still a house fire. I'm presuming the fire was not electrical in origin?
 
kwired said:
Did you ask why he thought he needed 10 AWG? If he wanted "cheap" 14 AWG was sufficient for everything but SABC's, laundry, bath, and certain fixed appliances.
Click to expand...


Opened up another point there-It could be that the guy had some 10 laying around, used it to save money and now won't have it pulled out b/c he doesn't want to pay for a rewire- but if that was the scheme, thing is, any money he saved by not buying the 14 is now easily gone when our op has to clean up his mess.
 
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