# Circuits and Wire Gauge...



## MrAtlantis (Aug 27, 2015)

Preparing to install lighting and several outlets in my basement/shop.

What gauge wire is recommended?

I was thinking:


Lighting on a seperate 15a breaker, running 14-2. Should be adequate for, at most, 4 ballasts.
Table Saw and router on a 20a breaker, running 12-2.
1 maybe 2 additional outlets on 20a breakers, running 12-2 also for vacuum, chargers, palm sander, etc.

Should I go 30a, and run 10-2 for the table saw? Or is this overkill?

I'll check my equipment for ratings and such, but what's typical?

Any guidance would be appreciated.


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## oldnovice (Mar 7, 2009)

15 amp circuit 14-2 is OK where I live now, but in my old basement shop I was forced to use conduit and GFCI outlets to comply with local codes.

You can find most of the general wiring codes for wire size and amperage on the Web, but there are also local codes, i.e. as I wrote above, that you may have to follow. You may want to follow these local codes in case something goes wrong and insurance gets involved or if you have the home inspected for a future sale. In California non compliance adds complexity for a property for sale.

If you ever plan to get a more than 2 HP or large dust collection system saw you may want to consider some 220 VAC wiring. It doesn't need to be connected until you want to use it but getting all the wiring done at once is a great time saver.

That's my two cents worth!


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## Holbs (Nov 4, 2012)

Add a 20amp 110v circuit in ceiling for a reel cord or something. You will be thankful later on


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## TinWhiskers (Oct 17, 2015)

Prices for LEDs have dropped a lot. Now is the time to convert. I converted to LED tubes 6 mo ago.


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## Tennessee (Jul 8, 2011)

Tin, I think I'll look for LED's when I finally run out of T-12 bulbs. I think I have a little over a case left.

Atlantis, 14-2 is fine for lighting. I ran 12-2 since I had plenty on the roll and didn't have to buy a roll of 14-2.

12-2, 20 amp definitely for all your 120VAC tools and outlets. You may or may not have to use conduit. GFCI is also probably in the mix.
I just this year upgraded my incoming electric service and panels, and the inspector didn't mention a thing about my non-conduit wiring in my shop, nor the crazy amount of tools I have plugged in at any particular time. Just looked at the breaker size in the new panels, wire size, and said all was well. Some of that was grandfathered, I am sure. Depends on where you live and who you think will see the work. Also always, always think in terms of reselling the house and what the inspector for the new owners would say, even if you have solid plans to die there. So stick to the code as much as possible even if there will be no inspection right now.


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## joey502 (Mar 30, 2014)

My shop is wired to local codes, as of 2008 anyway. 60 amp sub panel in the garage, can not remember the wire size from the main to the sub. The lighting is 13 - 2 lamp linear fluorescent fixtures on a 15 amp circuit with 14/2. There are 6 - 20 amp circuits, all ran with 12/2, around the shop, all GFCI protected. I used the gray plastic conduit and metal boxes on the walls because my garage was insulated and covered in drywall.

My table saw is a 1.75 HP hybrid, it is on a single 20 amp circuit. No problems there. The start up draw on my saw is just under 13 amps.

If you have kids in the house I would suggest adding a way to shut the shops power down when you are not there. I installed a 60 amp general duty switch between the main panel and the sub panel 7' from the floor. It can be locked out when I am not around.


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## Holbs (Nov 4, 2012)

you will have to research local codes about GFCI in your shop. In a garage setting, the first electrical plug in a specific circuit has to be GFCI and following plugs do not (was this local or national code? I forget). But you are in the basement so unsure what codes you have to follow.
Lighting: always safe to have 2 circuits for lighting incase one circuit cuts out while you are in the midst of a table saw cut. I have 3 zone lighting in my 2 car garage: 1 above the door (not used when door is up), other end of garage, and single light bulb hooked to my main house circuit.
For my code, I ran romex for everything in the ceiling and inside the walls, including 14/2 for lighting, 12/2 110v for machinery, 10/2 for 220v for machinery (10/2 might be overkill where 12/2 for 20amps would suffice, but I like to keep options open). By code, you can not put romex inside pipe (some kind of possible heat build up). Any wiring junction (if you go romex to that 3/8" metal flex with wiring inside) has to be done in a metal 4"x4" junction box.


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## helluvawreck (Jul 21, 2010)

Before you do anything you had better take a look at the fine print in your insurance policy. Insurance companies are beginning to take a dim view of do it yourself electricians.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com


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## DrTebi (Jun 16, 2009)

> Prices for LEDs have dropped a lot. Now is the time to convert. I converted to LED tubes 6 mo ago.
> 
> - TinWhiskers


Me too. Installed 3 × 2 LED tube lights in my workshop. I used Home Depot or Lowes workshop lights, removed the ballast, and rewired for the LED Tubes. Philips LED Tubes are definitely my favorites, I tried some other ones before, they didn't last long and the light was weaker and yellowish.

My workshop is the best lit room in the house!


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## oldnovice (Mar 7, 2009)

+1*Charles*, insurance companies are getting very fussy so better be safe than sorry!

I would take the LED light suggestion from *TinWhiskers* too. I just replaced all my fluorescent and CFL lights in my garage. They are brighter, start immediately, do not hum, and will not draw any bugs as there in no UV content. See my review about the Feit lamps from Costco that I, and other LJs, installed.


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## DrTebi (Jun 16, 2009)

I also recommend outlets in the ceiling. It's very handy at times. I have my Air Filtration hanging from the ceiling and plugged in right there, too.


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## crank49 (Apr 7, 2010)

As said, 14-2 fine for lights.
12-2 good for most others.

Nothing about a 220/240 volt circuit requires a 30 amp circuit by default.
Wire size is determined by the load requirements; not voltage.

The circuit for the ceiling mounted reel is a good idea.

I would run 12-3 for the table saw in case I ever upgraded to a 240 volt saw.


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## WhyMe (Feb 15, 2014)

> *I would run 12-3 *for the table saw in case I ever upgraded to a 240 volt saw.
> 
> - crank49


If you're talking about NM-b (Romex), 12-3 isn't needed for 240. There is no neutral for just 240V. XX-3 NM-b is 3 current carrying conductors plus a ground. XX-2 NM-b is 2 current carrying conductors plus a ground. If you're talking about cordage then the ground is counted in the numbering.


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## TopamaxSurvivor (May 2, 2008)

*Should I go 30a, and run 10-2 for the table saw? Or is this overkill?*

#10 certainly will not hurt anything. You never know when you might want to go larger for TS, dust collection and compressors. Depending on the length of run, #10 will have lower voltage drop. Last small shop I wired before I retired, I ran #10 for his TS outlet circuit even though it wasn't required. The code is just a minimum, not a maximum ;-)


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## Knothead62 (Apr 17, 2010)

14-2 is OK for lighting but why buy two different wire sizes? I would recommend going with 12-2 for all wiring for 120V. As mentioned, check local codes to make sure you are covered to sell the home or if something goes wrong.


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## splintergroup (Jan 20, 2015)

I agree with Crank, run 12/3 20A and you can set it up at the outlet for 110V, then easily switch to 220V later,


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## MrAtlantis (Aug 27, 2015)

Much to consider, but my questions have been answered. Thank you everyone!



> ...you may want to consider some 220 VAC wiring. It doesn t need to be connected until you want to use it but getting all the wiring done at once is a great time saver.
> 
> That s my two cents worth!
> 
> - oldnovice


 
I was thinking the same thing shortly after posting. Thank you.



> Add a 20amp 110v circuit in ceiling for a reel cord or something. You will be thankful later on
> 
> - Holbs


 
I will do this - in triplicate actually, thank you.



> Prices for LEDs have dropped a lot. Now is the time to convert. I converted to LED tubes 6 mo ago.
> 
> - TinWhiskers


 
I have some ballasts already lying around, so I'll use these first to save money. Once I finish the shop real nice in the future (insulate basement) - I'll make the ultimate switch.



> ...So stick to the code as much as possible even if there will be no inspection right now.
> 
> - Tennessee





> Before you do anything you had better take a look at the fine print in your insurance policy. Insurance companies are beginning to take a dim view of do it yourself electricians.
> 
> - helluvawreck


 
I'll communicate everything with my home inspector and insurance company prior to installation.



> *I would run 12-3 *for the table saw in case I ever upgraded to a 240 volt saw.
> 
> - crank49
> 
> ...


 
Ok, this is where I'm a little confused… ##-2 nm Romex carries two jacketed wires, and a bare ground. ##-3 nm Romex carries three jacketed wires, and a bare ground. If at the junctions, I only need two wires and a ground, why would I need to use ##-3? Unless of course I plan to have a 240 hook-up, right? Otherwise, if I use ##-3, either the bare ground or one of my jacketed wires won't ever see any action.
Please correct me if I'm wrong.

However, I spoke with our electrician recently at my job - he mentioned that the spare ground can, and should be attached to the junction box (in the events of metal casings and tubes).



> ...The code is just a minimum, not a maximum ;-)
> 
> - TopamaxSurvivor


 
Agreed, I'll consider when budgeting for the project.



> 14-2 is OK for lighting but why buy two different wire sizes? I would recommend going with 12-2 for all wiring for 120V. As mentioned, check local codes to make sure you are covered to sell the home or if something goes wrong.
> 
> - Knothead62


 
Smart. Will do.


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## MrAtlantis (Aug 27, 2015)

> ...If you have kids in the house I would suggest adding a way to shut the shops power down when you are not there. I installed a 60 amp general duty switch between the main panel and the sub panel 7 from the floor. It can be locked out when I am not around.
> 
> - joey502


 
I will definitely be doing this, with a 60a as well. Thank you!


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## WhyMe (Feb 15, 2014)

> *I would run 12-3 *for the table saw in case I ever upgraded to a 240 volt saw.
> 
> - crank49
> 
> ...


You only need 2 conductors plus ground cable (XX-2) to get either 120V or 240V. Using 2 conductors for 120V is to use one conductor for hot and one conductor for neutral. For 240V both conductors are hots, no neutral. The only reason to use 3 conductor cable is for multiwire circuits where the neutral is shared between two circuits or where used for 3-way light switches and such. Three conductor cable is used for things such as ranges because of the need for both 120V and 240V at the appliance. To use 3 conductor cable for wiring a normal 120V or 240V circuit is usually a waste of the 3rd wire. The bare ground is always used. One of the three current carrying conductors ends up not being used.


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## Knothead62 (Apr 17, 2010)

Black, white, green (ground) for 120V. Black, red (extra hot line), white, green for 220/240V. Basically the black and red are carrying 120V each; using the four wire cable will give the high voltage needed for the high voltage tools.


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## daddywoofdawg (Feb 1, 2014)

if you have a shop sink or laundry sink you need a gfci within I think 10'.


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## rwe2156 (May 7, 2014)

Mr Atlantis:

I have enough experience to tell you some of the posts here are not correct.

I've wired a house, a business and 2 shops and I've worked shoulder to shoulder with professional electricians on several occasions. And even still, I think I know enough but I quit giving advice because on a forum you have no idea who I am or what I know. IOW its cheap, unvalidated advice.

I have gotten different opinions from licensed electricians, so its not all cut and dried.

Some things are simple, yes, but IMO most posting here regarding electrical makes it way to complicated and confusing.

Please please PLEASE consult an electrician before you do anything.


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## TheFridge (May 1, 2014)

Your original plan sounds good.


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## splintergroup (Jan 20, 2015)

> You only need 2 conductors plus ground cable (XX-2) to get either 120V or 240V. Using 2 conductors for 120V is to use one conductor for hot and one conductor for neutral. For 240V both conductors are hots, no neutral. The only reason to use 3 conductor cable is for multiwire circuits where the neutral is shared between two circuits or where used for 3-way light switches and such. Three conductor cable is used for things such as ranges because of the need for both 120V and 240V at the appliance. To use 3 conductor cable for wiring a normal 120V or 240V circuit is usually a waste of the 3rd wire. The bare ground is always used. One of the three current carrying conductors ends up not being used.
> 
> - WhyMe


Correct, but The 12/3 is a bit more versitile. You can use it as a 220V branch for higher HP motors (2 hots) and also use the neutral (the "3" in the 12/3) if that tool also has a 110V accessory light built in. If the 220V is not currently needed, the 12/3 creates two 110V 20A branch circuits that share a neutral (wired to opposing phases).

RWE has the "word" however, nobody knows if you really are just a dog who owns a computer and accessed the internet…. 
Local pros have the knows!


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## WhyMe (Feb 15, 2014)

Mr Atlantis:
I just don't agree with the notion of the possibility of switching voltages of circuits or maybe needing to power a piece of equipment that takes 120/240V to justify running XX-3 for a general purpose 120V outlet circuit. I've seen too often wiring be done with the "maybe one day" feeling only to see it never happen. Wiring needs to be planned and designed for the intended use. Trying to wire as one size/type fits all for the "maybe one day" is not a good plan.

There was a comment about GFCI outlets by a sink. Your basement shop needs to have all the 120V outlets GFCI protected. NEC 210.8(A)(5)


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## MrUnix (May 18, 2012)

> I just don t agree with the notion of the possibility of switching voltages of circuits or maybe needing to power a piece of equipment that takes 120/240V to justify running XX-3 for a general purpose 120V outlet circuit. I've seen too often wiring be done with the "maybe one day" feeling only to see it never happen.


But if/when it does, it sure makes it a lot easier than pulling new wire 

Cheers,
Brad


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## WhyMe (Feb 15, 2014)

> I just don t agree with the notion of the possibility of switching voltages of circuits or maybe needing to power a piece of equipment that takes 120/240V to justify running XX-3 for a general purpose 120V outlet circuit. I ve seen too often wiring be done with the "maybe one day" feeling only to see it never happen.
> 
> But if/when it does, it sure makes it a lot easier than pulling new wire
> 
> ...


That's why running surface boxes and conduit in a workshop makes more sense than burying NM in a wall.


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## crank49 (Apr 7, 2010)

I suggested the 12-3 because It can provide two circuits of 120V, 20A each. This is very useful for powering a saw and a dust collector from the same quad outlet box. Then if you need a 240V circuit, you have all you need. Some other appliances, like stoves for instance, actually require all three wires plus the ground. I'd feel secure in knowing I had all my bases covered with the 12-3 w/ground cable. Some electronic controls might, in the future, need the neutral to power 120V circuits while the motor needs the 240V.


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## Cato (May 1, 2009)

Just to throw more in the mix, lol, I just had my garage done for my shop about 2 weeks ago. I was going to do it myself and have done so in the past but being busy at work I was running behind on it, and with a brand new house decided to get a licensed electrician. Haha, okay so one just happened to be at my neighbors doing the same type thing.
He ran a 20amp 220 for my Jet TS and then 4 120v outlet boxes with two circuits to each, where I wanted them. Each box has two pairs of receptacles, one white and the other black denoting the circuit difference. The two 20 amp 120v circuit breakers are GFCI. 
I really like the way he did it, and its going to work out very nicely having two circuits in each box.


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## Knothead62 (Apr 17, 2010)

IMHO, having two different circuits in one box would not be a good idea. Unless the plugs are different (they should be) where they wouldn't interchange. Never saw it done that way- should have separate boxes for each circuit.


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## Cato (May 1, 2009)

Knothead, yes two sets of plugs one white set for a circuit and one black set for the other in each box.


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## WhyMe (Feb 15, 2014)

> IMHO, having two different circuits in one box would not be a good idea. Unless the plugs are different (they should be) where they wouldn t interchange. Never saw it done that way- should have separate boxes for each circuit.
> 
> - Knothead62


I believe Cato is saying there are two 120V circuits in one box, not 120V and 240V together.


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## Cato (May 1, 2009)

Whyme, yes the 240v is separate and in its own receptacle box and then i just posted a pic of 2 separate 120v circuits in one box all black receptacles are one circuit, all whites another.


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## kelvancra (May 4, 2010)

Just wired my shop [some more].

I have five 30 amp (10 gauge) circuits. One for my table saw, one for my 3hp collector, one for my 1-2 hp collector, one for my jointer and one for a ceiling heater.

I have five 20 amp (12 gauge) circuits. They leap frog over each other, rest about four foot up the walls, for easy access and to avoid being hidden by a bench or other item, hide in plain sight on the ceiling, and travel out doors (through the walls), in case I need to plug in a weed eater, electric chain saw or something else.

I have three fifteen amp (14 gauge) circuits. One is for all the exterior night and security lights. One is for the garage portion. Finally, two are for the work area.

The shop area lights are on two circuits so one breaker can trip and I'll still have about twelve four footers (flourescents and LEDs) shedding light on a running saw. One is on a three way and one is on a four way (between the two man doors in the shop and the garage). The garage has a motion sensor on one part of the circuit so anyone going in the garage or getting out of a car will, automatically, have light both in the garage and just inside the door of the shop, to allow them to see their way to the man door.


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## TheFridge (May 1, 2014)

Knot head, multiple circuits in a box is pretty much the norm.


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## REO (Sep 20, 2012)

I have wired several shops with 120 and 240 in the same quad box. two 120v outlets and one twist-lock 240. the GFCI cant be used to protect the string though a separate GFCI outlet has to be used for each one, because all of them will trip. the latest was just finaled this summer.Outlets over 20 amps have to be individually protected. Many inspectors wont sign off on wire over #12 to daisy chained outlets.


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## rwe2156 (May 7, 2014)

> five 30 amp (10 gauge) circuits. One for my table saw, one for my 3hp collector, one for my 1-2 hp collector, one for my jointer and one for a ceiling heater.
> -------
> multiple circuits in a box is pretty much the norm.


Couldn't help but smile when I read these…..
Why do I keep looking at this thread?????

Here is a fact: One of these guys can save you a lot of money


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## Knothead62 (Apr 17, 2010)

OK, thanks for the clarification. Still, never seen circuits split that way. I've lived in a lot of houses in my time.


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## kelvancra (May 4, 2010)

No, they can't [save me a lot of money]. He, or she, is not going to install circuits in my shop for the cost of a roll of ten gauge, some breakers and a few wire staple

There is, absolutely, nothing wrong with running a ten gauge / thirty amp circuit to power my fifteen amp dust collector. In fact, running twelve gauge would be at or near a fools errand, since it actually consumes that much running, which would leave a five amp margin, had I cheaped out and ran twelve.

Ten gauge on each of the circuits allows me a whole lot more options in the future. It also means I don't have to pay out the nose or work my butt off to upgrade the circuit.

Oh, and I used to belong to that union, back in the day, until I moved on to electronics. I have friends and associates who yet belong (are electricians) and we've disagreed on more than one occasion.

Many electricians are minimalists and in favor of doing only what code, or the job requires. I'm not. I'm in favor of looking to the future and considering things like that I might want to move my collector, saws and other equipment, or the high cost of redoing (including redesigning wall use to accommodate conduit) or adding circuits down the road.

I've worked systems that demanded reliability well beyond what is required for houses and shops (there is no walking back from a sea or space voyage). Within reason, larger gauge was permissible, unless weight and room, or the ability to fit terminations in a load device, were an issue, since the worse side effect of larger wire is less line loss.



> five 30 amp (10 gauge) circuits. One for my table saw, one for my 3hp collector, one for my 1-2 hp collector, one for my jointer and one for a ceiling heater.
> -------
> multiple circuits in a box is pretty much the norm.
> 
> ...


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## rwe2156 (May 7, 2014)

When I say save you money I mean keep you someone from making a mistake that will cost in the future.

I don't know what "options" you will have other than running 5HP machines with FLA's over 25A, but hey, if you want to run 3Hp/15A machines on individual 5HP rated circuits, that's your prerogative.

I'm just saying when people with low knowledge have nothing to go by other than you sound like a pretty smart guy.

Not meant to rile anyone, just sayin'..............these forums are not good places for elect. info.


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## kelvancra (May 4, 2010)

Your points about taking electrical advice from strangers is wholly valid.

For me, like I mentioned, just one of my tools actually draws fifteen amps. True, twelve gauge allows twenty, at least for a little while, as you know, no circuit should run at full capacity for any duration. For me, a five amp buffer is pushing. In part, this is because I only ran the amp meter with no load on the 3 horse collector. More load might push the circuit on over.

The simple of it is, I'm a fan of overkill for a reason - real world events. For one example, some jurisdictions allow fifteen amp conductor for outlets. However, people being what they are, some of them will dump a space heater on the circuit, or two, which is also running the stereo, a clock and who knows what else. Then there is the cost of updating, after all the rock is on.

Really, in the scheme of things, is saving ten or fifteen bucks worth it when deciding between 14 or 12 gauge for outlets? Even the sixty dollar difference between a two hundred fifty foot roll of 10 and 12 gauge seems insignificant to me, in consideration of how long the circuits will be in place and the hassle they could alleviate in the future.



> When I say save you money I mean keep you someone from making a mistake that will cost in the future.
> 
> I don t know what "options" you will have other than running 5HP machines with FLA s over 25A, but hey, if you want to run 3Hp/15A machines on individual 5HP rated circuits, that s your prerogative.
> 
> ...


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## DKV (Jul 18, 2011)

What's the price difference per foot between 10, 12 and 14 gauge?


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## WhyMe (Feb 15, 2014)

> I don t know what "options" you will have other than running 5HP machines with FLA s over 25A, but hey, if you want to run 3Hp/15A machines on* individual 5HP rated circuits*, that s your prerogative.
> 
> *I m just saying when people with low knowledge* have nothing to go by other than you sound like a pretty smart guy.
> 
> ...


Speaking of low knowledge… a 30 amp circuit is not NEC compliant for 5HP motor operated equipment. You need a minimum of a 35A circuit.


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## RichardHillius (Oct 19, 2013)

> What s the price difference per foot between 10, 12 and 14 gauge?
> 
> - DKV


That's not the question you should be asking. The question you should be asking is how much time does it take to replace 14 gauge wire with 10 or 12 gauge and how much is that time worth to me? I don't know about everyone else but I know over time the tools in my shop will change and hopefully grow so having the wire in the walls to accommodate that growth just seems like the smart thing to do.


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## RichardHillius (Oct 19, 2013)

> What s the price difference per foot between 10, 12 and 14 gauge?
> 
> - DKV


That s not the question you should be asking. The question you should be asking is how much time does it take to replace 14 gauge wire with 10 or 12 gauge and how much is that time worth to me? I don t know about everyone else but I know over time the tools in my shop will change and hopefully grow so having the wire in the walls to accommodate that growth just seems like the smart thing to do. I don't collect tools and tend to buy newer so the biggest machine I anticipate having in my shop would need is 240V single phase 30 amp so when I do pull new circuits I plan around that potential future need.

- Richard H


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## eflanders (May 2, 2013)

Proper wire guage is determined by both the load and the length of run. Use and go by the building codes in your local area only or you may have issues later when you try to sell and/or insure.


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## TheFridge (May 1, 2014)

hope things are working out

Don't listen to rwe. He has girl parts.


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