# Adding a 20a, 240V outlet in my garage; conduit / code questions



## kooshball (Feb 14, 2010)

I plan to add a 20A 2-pole breaker to my existing sub-panel in my garage and run via external conduit a line to feed a surface mounted L6-20 outlet for my new table saw.

With this approach do I need steel conduit and a steel receptacle box or can I simply pick up what ever is cheapest / most user friendly at the hardware store (PVC, flexible, etc). I am planning on mounting the box "switch height" but is there a specific minimum height that should be maintained above the garage floor?

Thanks for the help.


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## Wizard1500 (Jul 12, 2009)

I don't know what the code is for where you live, but personally, I would use the metal conduit and metal box.....I ran a line for my 2hp dust collector a couple of months ago, and that's what I used.....when it comes to electricity, and 240 in particular, I don't believe in cheaping out....but that's just me.....


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## bb71 (Jan 23, 2010)

If you're surface mounting, why not use BX? It's good enough for industrial applications.


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## woodman42 (Aug 6, 2007)

Where will the conduit run? In wall, on floor, ceiling?
If it will be in a place that it can come in to contact with something that could penetrate the conduit you definitely want to use EMT.
Always us a heavy duty box. If it ever gets hit by anything, you want it to withstand a pretty good blow.
I ran my conduit in the attic, then used a heavy duty drop from the ceiling to my table saw with a twist lock connector.


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## TimPa (Jan 27, 2010)

options are metallic conduit, non metallic conduit (plastic), and bx armored type cable. if your ceiling is open, you can run 12/3 romex in there, then drop in conduit. i like to keep outlets and switches at least 48" off the floor because of gasoline vapors in a garage. check with some local electrical guys for your code though.


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## kooshball (Feb 14, 2010)

woodman42 said:


> Where will the conduit run? In wall, on floor, ceiling?
> If it will be in a place that it can come in to contact with something that could penetrate the conduit you definitely want to use EMT.
> Always us a heavy duty box. If it ever gets hit by anything, you want it to withstand a pretty good blow.
> I ran my conduit in the attic, then used a heavy duty drop from the ceiling to my table saw with a twist lock connector.


The line will be run on the wall (interior wall of my garage), I can't run through the area above the garage as it is finished living space.

Thanks


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## woodnthings (Jan 24, 2009)

*All my shop wiring is in EMT*

It's easier to add or move outlets as required. I even used it for the overhead lights and 3 way switches. It's a pain and took about a week, 
but the finished job looks great. For your case adding one outlet it's about a 1 hour job. Located a stud where the box will go, screw it on temporarily and install the fittings on the main and outlet. Cut the EMT to fit between or use 2 pieces and a coupler and run a pull wire inside as you go. Pull the new conductor through allowing extra length for wiring to the breaker and outlet and you're 95% done. Wire up everything "correctly" and wait for you new saw to arrive! :yes: bill


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## frankp (Oct 29, 2007)

EMT isn't really that much more than PVC (at least in my area) and it's the right way to do it. That said, I ran "electrical grade" PVC, whatever that means, when I did the same thing for my bandsaw a few months back. It's grey PVC and doesn't make quite the same mess when cutting that the white (plumbing) PVC does. I was told by the appropriate people here that for my area EMT was only required for commercial spaces.


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## rrbrown (Feb 15, 2009)

kooshball said:


> The line will be run on the wall (interior wall of my garage), I can't run through the area above the garage as it is finished living space.
> 
> Thanks


 
That's why they have fish tapes. Wires can be ran anywhere and any wall can be moved you just need the knowledge,experience and tools to do the job.

If you want to use conduit go with the metal over plastic.

You would have to check for code for minimum height for outlets but if your mounting it switch height you should be fine.


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## mdlbldrmatt135 (Dec 6, 2006)

Make sure the conduit is sized with the proper airspace!!!


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## TS3660 (Mar 4, 2008)

mdlbldrmatt135 said:


> Make sure the conduit is sized with the proper airspace!!!


Proper airspace????


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## kooshball (Feb 14, 2010)

mdlbldrmatt135 said:


> Make sure the conduit is sized with the proper airspace!!!


I will run 10-2 for the outlet and plan to use 1/2" conduit; will this work safely?


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## TS3660 (Mar 4, 2008)

If there's one lesson I've learned while wiring my shop it's that the conduit should always be bigger than you think you need. Just in case later on you want to run another wire through it.


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## rrbrown (Feb 15, 2009)

kooshball said:


> I will run 10-2 for the outlet and plan to use 1/2" conduit; will this work safely?



If your running 240v then you should use 10-3 with ground. 2 hot, 1 neutral and the ground. Allot of equipment requires a nuetral and a ground, not to mention it is the proper way to run it. You can use 10-2 but it could cause problems in the future if the extra wire is required.

As for the conduit being big enough to add another wire if needed. That would depend on if it's underground, threw a slab or an extremely long hard to get to run, which i would then say definitely. If not then it's not needed but a choice. The wire should fit easily and not be forced 10-3 with ground would probably be best with 3/4" but test the fit to be sure. Just my .02


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## nblumert (Oct 15, 2008)

I would absolutely use the metal EMT, I think its only a few bucks a stick at Home Depot. I would also say a metal box with a metal face plate. For only 1 box, it shouldn't be expensive at all. Just do it the right way the first time. If something falls on the metal EMT, it cant cut the wires, now if you used something else and it cut the wires, you better watch out. Electricity ain't no joke. I can show you pictures of what I have in the garage if you would like, just let me know.
Nick


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## 47_47 (Feb 8, 2010)

My 2¢. I'd run 1/2" emt conduit with 2) #10 black thhn and 1) #10 green thhn. 

If you want to future proof this for 240/120 volts at 30 amps, run 1) #10 thhn white. 

I'd mount the outlet at least 36" from the floor in a garage.


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## mdlbldrmatt135 (Dec 6, 2006)

I don't have my "Ugly's" handy at the moment.... you can't pack the conduit tight... you need airspace in there.


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## 47_47 (Feb 8, 2010)

mdlbldrmatt135 said:


> I don't have my "Ugly's" handy at the moment.... you can't pack the conduit tight... you need airspace in there.


Yes you are right, you just can't put as many wires in that will fit. In 1/2" emt you can have a maximum of 5) # 10 thhn wires.

Mike


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## woodnthings (Jan 24, 2009)

*The original question was for a 20 amp circuit*



kooshball said:


> I plan to add a 20A 2-pole breaker to my existing sub-panel in my garage and run via external conduit a line to feed a surface mounted L6-20 outlet for my new table saw.
> 
> But overkill is good! No 12 will work for 20 amps, no. 10 for 30 amps.
> :thumbsup: bill


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## rrbrown (Feb 15, 2009)

47_47 said:


> My 2¢. I'd run 1/2" emt conduit with 2) #10 black thhn and 1) #10 green thhn.
> 
> If you want to future proof this for 240/120 volts at 30 amps, run 1) #10 thhn white.
> 
> I'd mount the outlet at least 36" from the floor in a garage.


*Who runs individual wires for electrical ? That's the same thing as 10-3 with a ground but they or all in one wire. *


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## rrbrown (Feb 15, 2009)

woodnthings said:


> kooshball said:
> 
> 
> > I plan to add a 20A 2-pole breaker to my existing sub-panel in my garage and run via external conduit a line to feed a surface mounted L6-20 outlet for my new table saw.
> ...


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## kooshball (Feb 14, 2010)

OK so after reading all of these and talking to an electrician here is my plan of attack: I will go for 1/2" EMT and metal boxes with 10-2 wire and surface mount the outlet in a convenient location. I picked up all the parts on the way home and got out for under $60 (I am only going 5' away from the sub-panel).

Thanks for all the help!


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## pabloj13 (Dec 10, 2009)

kooshball said:


> OK so after reading all of these and talking to an electrician here is my plan of attack: I will go for 1/2" EMT and metal boxes with 10-2 wire and surface mount the outlet in a convenient location. I picked up all the parts on the way home and got out for under $60 (I am only going 5' away from the sub-panel).
> 
> Thanks for all the help!


Isn't this site awesome??


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## 47_47 (Feb 8, 2010)

rrbrown said:


> *Who runs individual wires for electrical ? That's the same thing as 10-3 with a ground but they or all in one wire. *


Richard,

I'm new here and do not want to get off on the wrong foot, but in conduit runs it is much easier to pull the individual wires than romex.

Mike


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## mdlbldrmatt135 (Dec 6, 2006)

In some areas you can't run romex in conduit. it has to be the individual stranded wire rather then the solid romex. the outer jacket is also considered extra insulation in some places.


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## woodman42 (Aug 6, 2007)

I would have gone with the 3/4 emt to give room for expansion, but thats just me.


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## woodnthings (Jan 24, 2009)

*true*



mdlbldrmatt135 said:


> In some areas you can't run romex in conduit. it has to be the individual stranded wire rather then the solid romex. the outer jacket is also considered extra insulation in some places.


For a 5 ft run, you can always strip out the wire from the romex and just twist and pull them thru together. The copper ground probably won't want to strip out, so you can just run a separate wire for the neutral, a different color or marked with color and a bare copper ground also. That'll give you the proper arrangement for code. I ran individual wires in my shop in the conduit, no romex! I bought 250 ft rolls and put them on a rod in a holder to pull from, and it worked great. No tangles! :thumbsup: bill


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## rrbrown (Feb 15, 2009)

:surrender:


47_47 said:


> Richard,
> 
> I'm new here and do not want to get off on the wrong foot, but in conduit runs it is much easier to pull the individual wires than Romex.
> 
> Mike


Don't worry about it Mike I was probably a little hard on you anyway. It's always good to have other people participate. :thumbup1:

If it's to hard pulling Romex in the conduit then it's probably not the right size conduit.

Hard was Pulling 125' of #4-3 w/ground out the panel up through the wall, through the attic back outside into conduit down the wall under slab and back up again into my shop wall and panel. Where there's a will there's a way.

Ok I surrender in some area's it may be required or preferred to use single strand wire over romex in conduit. I should have an open mind I guess. :surrender:

I still don' like it.:laughing:


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## 47_47 (Feb 8, 2010)

rrbrown said:


> I still don' like it.:laughing:


Yes there is more than one way to skin a cat. The main thing is we agree on using the #10 overkill wire :thumbsup:


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## bzbatl (Feb 10, 2009)

Is it legal to run your own electrical like this? I would think there's some sort of laws that only licensed electricians can do this sort of thing. I mean, there's laws for damn near everything else...


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## rrbrown (Feb 15, 2009)

Depends on the area I would think as to what requires a license or not. I have done allot of electrical work including wiring whole houses, shops and replacing electrical panels, some of which I had to have checked by a electrician and filed under their license. That said I have seen allot of stuff done by licensed electricians that is no where close to code. I have helped people including on this forum with problems caused by electricians previous work. 

There are allot of people especially on here that either were trained or learned along the way about electrical etc and are capable of helping each other out without being licensed. That said caution should be taken that you have the right advise which usually starts or ends similar to this. "You may have to check the codes in your area" or "This is how you do it but if you feel more comfortable call a licensed professional to do the job".


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## TimPa (Jan 27, 2010)

realize that romex, or non-metallic sheath, has an outer "abrasion resistant" sheath around insulated conductors (which happen to be solid). it's not intended to be an insulator. emt, a metallic sheath of similarly insulated conductors, which happen to be stranded (more flexible). 

if interested:
nec code (chap 9 tables 4,5) for conduit fill - 40% fill by cross sectional area. 1/2" emt conduit is 0.622 in sq.. over 2 wires 40% fill is 0.122 sq in.. 10 ga insulated thhn is 0.0211 sq in. so five conductors of that size is permitted (5 x .0211 is less then .122).


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## dennisf (Feb 5, 2010)

Check with your local building dep't. They are a big help in all the cities that I've asked for help.


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