polar8
Active member
I'm building a new detached garage. Do ALL the outlet circuits need to be 20A or is 15A alright for some of them, as long as I have ONE 20A circuit for outlets?
15A or 20A circuits in new construction detached garage?
- Thread starter polar8
- Start date
cdestuck
Well-known member
Not knowing your needs it’s hard to say. But as to myself, I’d never do lunches than all 20 amp circuits. Sure you’re not looking at a ton of money difference and 12ga is a bit harder to work with but easy. Do it rt the first time
I'd recommend most all of them 20A at the main use locations . . . ie sidewalls, up by the front of garage (ie divider between doors or overhead if one door - - hanging electric reel). Also, where ever you'll have a bench, make SURE you have 20A 120v circuit(s) there so you have mount a long power strip to bench and run most anything you want. You'll quickly overload a 15A circuit so just avoid it.
Reason for 20A circuits around the shop is you'll likely have portable compressor that you might be using that's 120v and you WILL want a 20A circuit for it. Other things like portable electric 120v heaters, table saw, chop saw, 120v welders, etc really NEED 20A circuit, especially if there's some other stuff sharing the circuit.
Later, you might "grow" into 2 compressors (ie portable 120v) and a stationary 240v (like 5 HP 60 gal). Think ahead for 240v circuits as well so consider planning for a large compressor, an air conditioner, welder, etc.
ONLY place I'd do 15A circuits would be "dedicated" stuff like trickle chargers for cordless tools in a cabinet, overhead hanging NG/LPG heater where it might only need a 15A circuit, etc.
Reason for 20A circuits around the shop is you'll likely have portable compressor that you might be using that's 120v and you WILL want a 20A circuit for it. Other things like portable electric 120v heaters, table saw, chop saw, 120v welders, etc really NEED 20A circuit, especially if there's some other stuff sharing the circuit.
Later, you might "grow" into 2 compressors (ie portable 120v) and a stationary 240v (like 5 HP 60 gal). Think ahead for 240v circuits as well so consider planning for a large compressor, an air conditioner, welder, etc.
ONLY place I'd do 15A circuits would be "dedicated" stuff like trickle chargers for cordless tools in a cabinet, overhead hanging NG/LPG heater where it might only need a 15A circuit, etc.
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sberry
Banned
20A for outlets and 15 for lights and certain equipment that should have dedicated. A lot of stuff needs the headroom for motor starts. I don't have a bunch of parasitic shate plugged in to tool circuits. a guy should have 1 or 2 where he can plug in a comp, welder or chop saw if he is going to use those tools.
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naturalgas
Well-known member
sberry
Banned
My neighbor has a few but actually runs most of the real power tools from a ceiling reel with a heavy cord. 2 general's serve the whole garage. He runs a tool at a time. I used to wire up lotso recepts but actually use a common power strip or 2 for that parasitic stuff that can cluster. Super easy to change or modify. Most of this stuff is long gone or obsolete.
Attachments
klassenl
Well-known member
All of my general use receptacles in my shop are on 15 amp circuits.
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sberry
Banned
There is a difference between circuits and recepts. The 15 recepts are fine.
malibu101
Well-known member
15A = 14AWG NM @ $43 per 250'
20A = 12AWG NM @ $68 per 250'
10¢ difference per foot at my local HD.
Breakers almost equal in price.
My opinion, working 12 is not that much harder than 14.
If the circuit can run fine on 15A (dedicated lighting and such) by all means do it.
Me personally, if the circuit is to feed any "general" outlets I'm 20A all the way.
20A = 12AWG NM @ $68 per 250'
10¢ difference per foot at my local HD.
Breakers almost equal in price.
My opinion, working 12 is not that much harder than 14.
If the circuit can run fine on 15A (dedicated lighting and such) by all means do it.
Me personally, if the circuit is to feed any "general" outlets I'm 20A all the way.
Crazyjake8493
Well-known member
For new construction, I would go 20A for all outlet circuits and 15A for lighting-only circuits, if you want to save a little on wire there.
Dick in Wisconsin
Well-known member
I went 20amps on all circuits, except those with for 240v A/Ca and the lathe, even the lights.
Most of the outlet boxes are duplex so I have four outlets at each location.
I did 6” walls with sheathing and styrofoam on outside so the window jams and sills (white PVC for jams and sills) are deep. In hind sight wish I would have put an outlet in each window jam. Window sill is great place to charge a phone or set a cordless tool charger.
Most of the outlet boxes are duplex so I have four outlets at each location.
I did 6” walls with sheathing and styrofoam on outside so the window jams and sills (white PVC for jams and sills) are deep. In hind sight wish I would have put an outlet in each window jam. Window sill is great place to charge a phone or set a cordless tool charger.
Not to be too picky but..............we $43 to $68 is 45% difference or 58% increase depending how you look at the calculations.
https://www.calculatorsoup.com/calculators/algebra/percent-change-calculator.php
Schurkey
Well-known member
Wisdom.
The guy that wired our "new-to-us" home--and the detached 2-car garage that is now my "new" shop--went a little tricky.
Both the house and the shop have duplex outlets where the lower outlets are powered by one circuit breaker, while the upper outlets are powered by a different circuit breaker. In the house, one or the other is controlled by a switch, so everything plugged into the upper (or lower...I forget) can be shut off when leaving the room. The other outlet of the two is powered all the time.
In the shop, they're not controlled by a switch. They're just different circuit breakers, so that I can run two items simultaneously from a single duplex outlet and not have to be concerned about overloading a single breaker.
The downside is that apparently the electrician "saved" money by using the crappiest outlets on Earth. I plug a cord into them...and the cord falls out of the socket. I'll be replacing most if not all the outlets over the winter. Of course, I'll have to break the connecting strap between the two outlets to isolate the two circuit breakers from each other.
If I were doing this from scratch, I'd put in enough switches by the door that controlled the outlets, so that I could shut off power to the whole shop (except perhaps the furnace, GDO, and security system) at the doorway. Nothing gets left-on by accident that way.
I wouldn't even consider using 14-gauge wire in a shop. I'm the sort that debates on whether to use 12...or 10 gauge.
minytrker
Well-known member
On something like that I always go over kill. I would do all 20amp circuits for outlets with 20amp outlets and 15amp for the lights. Besides the little extra cost now, you will never regret having too good of wiring but you will be kicking yourself later if you only have one 20amp circuit and need more once its finished.
15-20A breakers are the same price.
larry4406
Well-known member
I guess it depends on what you do in the garage. If its just storage and car parking, then go with 15A and buy yourself some beer with the savings.
If you do work in the garage with power tools, the savings from 15a quickly pisses you off when breakers start tripping. My last garage I built was during the construction boom and copper prices were sky high. My electrician gave me several rolls of 14/2 so I used that to wire my outlets. Well, once I started plugging in table saws, etc, the savings quickly became a joke but it was what it was.
My current house garage remodel was all done 20A with 12/2 for the outlets. My detached which is underway will also be done in 20A with 12/2 for the outlets.
If you do work in the garage with power tools, the savings from 15a quickly pisses you off when breakers start tripping. My last garage I built was during the construction boom and copper prices were sky high. My electrician gave me several rolls of 14/2 so I used that to wire my outlets. Well, once I started plugging in table saws, etc, the savings quickly became a joke but it was what it was.
My current house garage remodel was all done 20A with 12/2 for the outlets. My detached which is underway will also be done in 20A with 12/2 for the outlets.
EOC_Jason
Well-known member
Run a 20A circuit for all your outlets... Like others have said 12GA isn't that much more in cost over 14GA, and probably would cost more buying two smaller rolls of each than just one larger roll of 12GA...
If you already have 14GA then run that for the lighting, typically a 15A circuit is more than adequate for lights. Only exception would be in a house where lighting circuits can be shared across rooms to maximize amperage per circuit, but still...
Ever use a circular saw? Many are 15A or pretty close... Air compressors, industrial vacuums, 110V welders, etc, etc...
If you are going to buy a bunch of material at a big-box store, make friends with an associate at the pro desk, make a materials list, and often they can give you a decent discount on your order when you are buying a bunch of stuff...
If you already have 14GA then run that for the lighting, typically a 15A circuit is more than adequate for lights. Only exception would be in a house where lighting circuits can be shared across rooms to maximize amperage per circuit, but still...
Ever use a circular saw? Many are 15A or pretty close... Air compressors, industrial vacuums, 110V welders, etc, etc...
If you are going to buy a bunch of material at a big-box store, make friends with an associate at the pro desk, make a materials list, and often they can give you a decent discount on your order when you are buying a bunch of stuff...
teal95
Well-known member
I did all 20 amp circuits for outlets in my shop but I put in dual duplex outlets (4 outlets in each box) with the left 2 being on one circuit and the right 2 being on another. Then I hooked the breakers up so they're on opposite phases, so if I ever need 220 I just have to replace the outlet.
larry4406
Well-known member
I did the quad boxes with separate circuits as well. I chose to place the GFCI's in a convenient location to feed the string of circuits.
casmurbax
Well-known member
I went so overboard on my 18x24 garage.
I wired all my 120v circuits with 12-2. I then only put 2 - 20 amp receptacles on each breaker, why you ask, I had the room in the breaker panel and I had the wire. My brother cursed me but I didn't care.
I have 4 120v outlets on each long wall and back wall, along with one on each side of garage. 240v 30 amp by the garage door and another in back of garage as well.
Yup I over did it and I am glad I did. I don't think anyone ever said "I have to many 20a outlets".
I wired all my 120v circuits with 12-2. I then only put 2 - 20 amp receptacles on each breaker, why you ask, I had the room in the breaker panel and I had the wire. My brother cursed me but I didn't care.
I have 4 120v outlets on each long wall and back wall, along with one on each side of garage. 240v 30 amp by the garage door and another in back of garage as well.
Yup I over did it and I am glad I did. I don't think anyone ever said "I have to many 20a outlets".
lakeroadster
Well-known member
I guess the point is, as has been previously discussed, it really depends on what, or watt, you will be using as devices on the specific circuit(s).
15 Amps for lighting circuits, based on LED technology, sure.
But take that same circuit and throw old school incandescent bulbs in the mix.. maybe not.
15 Amps for lighting circuits, based on LED technology, sure.
But take that same circuit and throw old school incandescent bulbs in the mix.. maybe not.
Alchymist
Well-known member
Nothing new or tricky about any of that. Multi wire branch circuits and switched outlets have been around for a long time.
prostreetamx
Well-known member
Where I live it is required that all receptacle 120v circuits be wired in #12, even if you use 15a plugs. If there is only 1 plug on the circuit for a dedicated appliance then that receptacle has to be rated for 20a. I used all 20a plugs in my new garage since I had them and they are typically built a little better than the cheepo's. I also had plenty of breaker space available so each circuit only has a few plugs on them.
A 15 or 20 ampere receptacle of the same grade & brand will be equal, can't compare a spec grade 20A & low end residential grade 15A & say that because it's 20A it's better then the 15A. 15 & 20 ampere receptacles use the same innards.
14 AWG/ 15A for lighting & 12 AWG/ 20A for receptacles would be fine for the OP.
20 amp circuit and plugs all the way....when you consider a skilsaw could draw 12 amps cutting stair stringers or 4x material it really is a no brainer.
In my previous garage I used Hospital Grade plugs due to their superior ground grab feature and that is probably way overkill...but they were free from a demo so the current garage I used the Gray hi grab outlet....nothing like working on something and pulling the cord & plug out of the cheapo outlet...just my opinion....
In my previous garage I used Hospital Grade plugs due to their superior ground grab feature and that is probably way overkill...but they were free from a demo so the current garage I used the Gray hi grab outlet....nothing like working on something and pulling the cord & plug out of the cheapo outlet...just my opinion....
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Remember that code requires that all devices that share a yoke need to be able to be disconnected simultaneously. You need handle ties.
My shop, garage, and sewing room are wired like this, but with 4" square boxes, with a pair of duplex outlets. In each, the left hand outlet is on one circuit, the right on another. It's pretty handy.
48windsor
Well-known member
I agree with Malibu .
well spoken
well spoken
themiller
Well-known member
When I built my garage I spec'd a single 20A figuring I'd put in a subpanel shortly. Going 5 years later... I wish I'd have gone 2 x 15A. There were several times the first year or two I had to run into the house to reset the breaker until I learned how to manage power. Next garage I build will have A/B circuits at every receptacle location - so I can run a heat gun AND a compressor (or similar) at the same time, in the same location. When I do that - I'll probably do 2x15A everywhere. Never did I need a single 20A circuit, it was just a bandaid.
MikeF2316
Well-known member
I have only 2 15 amp circuits in my small shop, plus lights are on a different circuit. I only work alone, and I've never tripped a breaker, except for testing. Sometimes I wish I'd pulled 12 gauge, but back in the day I didn't know any better. In the winter I have to turn off one of the heaters when I use the drill press. I do have 6 duplex receptacles over my bench, 4 more at a cordless tool battery charging station and 2 more along each 12 foot wall.
My suggestion is to spend a bit more on cable and run all your receptacle circuits with 12 AWG [20a]. For your lighting branch circuits you can use 14 AWG [15 amp]. However, depending upon how many lighting outlets you have on a given branch circuit and depending upon the wattage of the fixtures you will use, you may be able to run fewer circuits if you use 12 AWG. The NEC Handbook has guidelines for sustained amperages on various circuits.
sberry
Banned
While multi wire circuits have there place its often confusing in small shops. A simple extra circuit or 2 does all this without a confusing bunch of ****.
sberry
Banned
When I was 20 and just starting to do this I was special, I needed more and better than most people, special recepts and switches, every fitting and box they ever invented with 4 extra circuits.
Lots of work and materials parked, never utilized, cost a lot extra for nothing. Today use 49 cent recepts and switches and as many common parts as I can.
If I think I need more run a wire for an extra circuit to another duplex for a heater or for heavy tools, a welder or comp type thing, sometimes not if we have the dedicated covered. A common garage has about the same demands of a common kitchen these days.
Lots of work and materials parked, never utilized, cost a lot extra for nothing. Today use 49 cent recepts and switches and as many common parts as I can.
If I think I need more run a wire for an extra circuit to another duplex for a heater or for heavy tools, a welder or comp type thing, sometimes not if we have the dedicated covered. A common garage has about the same demands of a common kitchen these days.
sberry
Banned
I can't even remember the last time I replaced an outlet or switch, only ones were old, very old and well used. Never a cheap replacement and I have some on benches with thousands of cycles, 1000's , way beyond what a common home garage could ever apply to them.
Some had/have higher currents, less use, 1 on a chop saw with 100's or 1000's and start currents of 75 a and run spikes above 30A easily, figured I would replace it but never did.
A couple on benches probably saw 10 and one maybe 20 thousand uses. Wore out a box of grinders and before battery drills saw a lot of use.
Some had/have higher currents, less use, 1 on a chop saw with 100's or 1000's and start currents of 75 a and run spikes above 30A easily, figured I would replace it but never did.
A couple on benches probably saw 10 and one maybe 20 thousand uses. Wore out a box of grinders and before battery drills saw a lot of use.
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If you are confused by multi-wire circuits, you shouldn't be touching electricity, except to plug things in.
Schurkey
Well-known member
What is a "yoke"?
All this was wired in '71, I think. That's when the house was built, anyway. Not much meets modern-day "code".
Why all the outlets are worn-out is beyond me, except to suspect they were cheap **** when new.
terabitdan
Well-known member
- Joined
- Jul 16, 2016
- Messages
- 152
A yoke is a strap, it refers to devices being tied together into a single unit. Examples are duplex receptacles, or duplex or triplex switches.
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n20junkie
Well-known member
I only buy 12 gauge for 120 volt stuff. You just never know.
Schurkey
Well-known member
...or 10 gauge.
AP514
Well-known member
Well, I am happy my guy put my Garage lighting on a 20 Amp breaker(15 Amp Breaker would not have cut it after Lighting upgrade)
I just added 24 LED fixtures to my shop. And @44 Watts per fixture it took the circuit Draw up 8.8 Amps to 14.6 Amps Total. The Whole Garage Lighting is on 1 C/B....
The 20 Amp C/B still gave me cushion along with the associated 12 ga. wiring....This just saved me from adding another Circuit or Rewiring
Good call electrician
I just added 24 LED fixtures to my shop. And @44 Watts per fixture it took the circuit Draw up 8.8 Amps to 14.6 Amps Total. The Whole Garage Lighting is on 1 C/B....
The 20 Amp C/B still gave me cushion along with the associated 12 ga. wiring....This just saved me from adding another Circuit or Rewiring
Good call electrician
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sberry
Banned
In common home garages there just isn't much gain or need for much more than a simple circuit to a box designs. The need for multiple circuits to the box is greatly over estimated. I know lots of guys made it just fine with a couple generals in the whole place especially if they had dedicated for air comp and maybe a welder circuit.
They worked for decades without tripping a breaker. Even my shop could use 2 pretty easily however the layout makes more a practical matter and easier to wire. The ability to daisy chain with cable in realatively short walls makes it so much more simple. .
I remember one of the first garages I did, had so many features it confused everyone but me, they never did get utilized for all the effort.