How Many Receptacles on Each Circuit?

[BentBierz]

I am adding 1200 sq. ft. onto my shop and am currently laying out the electrical. I will have plenty of power and circuit breaker space for the addition, with two 100 amp subpanels coming off of a 400 amp main panel. I know what equipment needs dedicated circuits, where I need my 240v circuits, but what I am currently struggling with is how many general purpose 20 amp receptacles to put on each branch circuit which also determines how many branch circuits I run.

If circuit breaker space was no issue and you weren't overly concerned with how much copper you were running (I don't want to grossly waste copper but I have a lot of spools that I can use), how many general service receptacles would you put on each circuit? There is also the added cost of GFCI but I have a bunch of those available from other projects. At a minimum, I will be running two circuits on each of the four walls. Thanks.

 

[rlitman]

In my 400 sq ft garage, I have one circuit dedicated to plugged in tools with a single GFCI receptacle at the head of the circuit. I'm never going to be cutting on the chop saw with one hand while using the bandsaw in another. How many people do you expect to be working simultaneously in your shop?

 

[aka Larry]

My shop is 1600 SF. I have two runs of (5) 20A duplex receptacles with a GFCI at the start of each run. I laid mine out this way mainly to be able to move my welder anywhere in the shop w/o worrying about it tripping the breaker.

 

[Shiftless]

At a minimum, I will be running two circuits on each of the four walls. Thanks.

I realize that this is Garage Journal where overkill is deemed barely adequate, but IMHO,
eight 20 amp general use circuits is enough.

 

[mm08822]

Unless you have large loads that remain plugged in AND drawing power, 2 circuits is plenty. Put your money into adding enough recepts for location convenience and you will be happy.

You don't need 20a receptacles either.

Buy good quality 15A spec grade recepts.

 

[The Metric System]

I would put as many receptacles per circuit as are required to give me one every 4 feet along the perimeter of the room.

 

[mike93lx]

How many things can you run at once? I find my limit is about 2.

Running 2 circuits to each wall is kind of nuts unless it greatly simplified wiring.

A multiwire branch circuit to a dual receptacle box can work well. One less wire to that, but then you need separate neutrals if you use a gfci

 

[rlitman]

How many things can you run at once? I find my limit is about 2.

Running 2 circuits to each wall is kind of nuts.

Agreed. That's why I asked how many people would be working in the shop. All assuming stuff that belongs on dedicated circuits (compressor and dust collection stand out here) don't go on these circuits.

 

[vwishndaetr]

As many as you want/can fit? There is nothing wrong/bad about having a lot more receptacles than you need. Whether you have 1 receptacle or 50, the breaker will do what it needs to do to protect the circuit.

Edit: I see you mentioned you'll do two circuits... In that case, my answer is the same but split the receptacles evenly between the two circuits so you have loads distributed evenly.

 

[MovingAlong]

I am adding 1200 sq. ft. onto my shop and am currently laying out the electrical. I will have plenty of power and circuit breaker space for the addition, with two 100 amp subpanels coming off of a 400 amp main panel. I know what equipment needs dedicated circuits, where I need my 240v circuits, but what I am currently struggling with is how many general purpose 20 amp receptacles to put on each branch circuit which also determines how many branch circuits I run.

If circuit breaker space was no issue and you weren't overly concerned with how much copper you were running (I don't want to grossly waste copper but I have a lot of spools that I can use), how many general service receptacles would you put on each circuit? There is also the added cost of GFCI but I have a bunch of those available from other projects. At a minimum, I will be running two circuits on each of the four walls. Thanks.

Number of receptacles is determined by location & layout. Could be dozens upon dozens. I'd never run anything less than a quad box every four feet in a garage these days.

Number of circuits is determined by usage & power draw. Might only be one if you're just running recharging your phone and running an LED fixture over the tool box OR might be a dozen if you're running commercial grade saws, mills, lathes, jointers, planers, etc...

But they are two completely separate things.

 

[larry4406]

When I wired my current garage, I provided (2) 120V20A circuits via 12/2 Romex.

I went from panel to a quad box by my garage door. I installed the GFCI's there as always accessible and not blocked by something.

From there, I daisy chained to other quad boxes around the perimeter of the garage. Left GFCI does left outlet while right GFCI does right outlet. So each quad box has 2 circuits in it. They are not interconnected within each box.

I think I have somewhere around 10-12 receptacles per circuit.

I have wondered if they should have the handles tied on the breakers (ie, use a 240V20A breaker instead of two 120V20A breakers). The panel is labeled as Right side outlets and Left side outlets but when I am gone, who would know what that means. Both 20A breakers are side by side, so easy to handle tie.

 

[mike93lx]

I have wondered if they should have the handles tied on the breakers (ie, use a 240V20A breaker instead of two 120V20A breakers)

Yes. You may be able to get an add on handle to combine them VS having to replace

 

[nh_yota]

I like the idea of alternating circuits for outlet runs on a wall.

For instance, say you have circuits A and B with duplex boxes:

A----------B----------A----------B----------A----------B

or with quad boxes:

AB----------AB----------AB----------AB----------AB

It's easier to do it with conduit.

 

[niget2002]

^ That guy posted same time I did. I have the second example.

I have 2 20A lines down each long wall of my shop with 4 receptacles on each line, 2 receptacles in each box (one receptacle from each line in each box). So, 4 dual boxes evenly spaced on each long wall.

My back wall has 4 receptacles on a separate circuit with two on each side of that wall's garage door.

 

[nh_yota]

I think conduit is a great idea in a finished garage because it makes it much simpler to reconfigure circuits without fishing through or tearing open a wall.

 

[larry4406]

Yes. You may be able to get an add on handle to combine them VS having to replace

Thanks Mike!

Found this handle tie for my CH breakers for $8.

 

[larry4406]

I like the idea of alternating circuits for outlet runs on a wall.

For instance, say you have circuits A and B with duplex boxes:

A----------B----------A----------B----------A----------B

or with quad boxes:

AB----------AB----------AB----------AB----------AB

It's easier to do it with conduit.

I have the quad box AB—-AB——AB etc.

I did not share the neutrals. Ran (2) 12/2 Romex.

 

[LopezBart]

I'm planning to run a 3 wire circuit w/ 240/120V gfci breaker down each long side of the shop w/ ample receptacles, and share the neutrals. This way I can add a 20A 240V plug anywhere I need one (big grinder, belt sander, etc), and I have two 120V circuits in each outlet box.

 

[Snip's]

I added a run of outlet boxes along opposite walls in my garage... Like larry4406 suggested...

I used two circuit breakers for each run... each breaker handled half the outlets in each box...
The first box had two GFCI receptacles, each feeding one receptacle along each run on the wall...


The receptacles in each box are running on one of two breakers and the entire run is protected by one of two GFCI's on each wall...
In case I trip one breaker or a GFCI, I can quickly plug into the the second outlet without necessarily running over to reset the run...

 

[mike93lx]

Thanks Mike!

Found this handle tie for my CH breakers for $8.

Rip off! Buy a 3d printer for several hundred and make your own

 

[Rc_Guy]

As many as you want/can fit? There is nothing wrong/bad about having a lot more receptacles than you need. Whether you have 1 receptacle or 50, the breaker will do what it needs to do to protect the circuit.

Edit: I see you mentioned you'll do two circuits... In that case, my answer is the same but split the receptacles evenly between the two circuits so you have loads distributed evenly.

That is what I did in our shop, every other outlet on 4 different breakers.

Now in our vending trailer, one outlet on each of 8-20amp gfci breakers.

 

[dscheidt]

When I wired my current garage, I provided (2) 120V20A circuits via 12/2 Romex.

I went from panel to a quad box by my garage door. I installed the GFCI's there as always accessible and not blocked by something.

From there, I daisy chained to other quad boxes around the perimeter of the garage. Left GFCI does left outlet while right GFCI does right outlet. So each quad box has 2 circuits in it. They are not interconnected within each box.

I think I have somewhere around 10-12 receptacles per circuit.

I have wondered if they should have the handles tied on the breakers (ie, use a 240V20A breaker instead of two 120V20A breakers). The panel is labeled as Right side outlets and Left side outlets but when I am gone, who would know what that means. Both 20A breakers are side by side, so easy to handle tie.

No need. they're independent circuits, sharing nothing but boxes. Anyone who doesn't understand there might be multiple circuit's wires in a box probably shouldn't be working on wiring. handle ties or two pole breakers are required on multiple wire circuits, because it's not at all obvious that a neutral can be live, and MWBC sometimes end up physically separated.

 

[sparky 1971]

I wire a lot of pole barn shops. I find out where the dedicated equipment like an air compressor, chop saw, etc. will be, then have the customer tell me where else he thinks he needs receptacles. Then I try to talk him out of half of them while explaining how there is no need to have one every 5' because in this day and age with battery power prevalent, 10-15' spacing for general use is plenty and even then, most of them won't be used and extension cords are going to be needed anyway with most tools being limited to a 6' factory cord. Then I push for one circuit per wall aside from the dedicated stuff. If he insists on one every 5' and a separate 20 amp circuit for each, I'll do it but it's a waste as far as I'm concerned. There's only so much that can be done at one time.

 

[larry4406]

I added a run of outlet boxes along opposite walls in my garage... Like larry4406 suggested...

I used two circuit breakers for each run... each breaker handled half the outlets in each box...
The first box had two GFCI receptacles, each feeding one receptacle along each run on the wall...


The receptacles in each box are running on one of two breakers and the entire run is protected by one of two GFCI's on each wall...
In case I trip one breaker or a GFCI, I can quickly plug into the the second outlet without necessarily running over to reset the run...

No need. they're independent circuits, sharing nothing but boxes. Anyone who doesn't understand there might be multiple circuit's wires in a box probably shouldn't be working on wiring. handle ties or two pole breakers are required on multiple wire circuits, because it's not at all obvious that a neutral can be live, and MWBC sometimes end up physically separated.

The reason I did not handle tie them initially, is because they are separate circuits and I have been in many 2 and 3 gang circuits where there were several circuits there. That made me think that one does not have to ensure the box goes black when a single breaker trips.

Also, like @Snip's said, I wanted the ability to just quickly move plug to other receptacle should I trip one or my brother is here and we are both using the separate circuits.

 

[mm08822]

No need. they're independent circuits, sharing nothing but boxes. Anyone who doesn't understand there might be multiple circuit's wires in a box probably shouldn't be working on wiring. handle ties or two pole breakers are required on multiple wire circuits, because it's not at all obvious that a neutral can be live, and MWBC sometimes end up physically separated.

And since each duplex recept is on a different circuit within each box vs both circuits on the same recept yoke.

 

[mike93lx]

I wire a lot of pole barn shops. I find out where the dedicated equipment like an air compressor, chop saw, etc. will be, then have the customer tell me where else he thinks he needs receptacles. Then I try to talk him out of half of them while explaining how there is no need to have one every 5' because in this day and age with battery power prevalent, 10-15' spacing for general use is plenty and even then, most of them won't be used and extension cords are going to be needed anyway with most tools being limited to a 6' factory cord. Then I push for one circuit per wall aside from the dedicated stuff. If he insists on one every 5' and a separate 20 amp circuit for each, I'll do it but it's a waste as far as I'm concerned. There's only so much that can be done at one time.

You're no fun

 

[RonnieC]

or with quad boxes:

AB----------AB----------AB----------AB

this is what I had done on my power tool wall. Shop vac, drill press, miter saw, planer, sander. It’s probably overkill for my one man shop but I was coming from a garage space where if I ran the table saw and shop vac for dust collection it would blow the only circuit.

 

[sparky 1971]

You're no fun

You sound exactly like my wife.

 

[dave*99]

I wire a lot of pole barn shops. I find out where the dedicated equipment like an air compressor, chop saw, etc. will be, then have the customer tell me where else he thinks he needs receptacles. Then I try to talk him out of half of them while explaining how there is no need to have one every 5' because in this day and age with battery power prevalent, 10-15' spacing for general use is plenty and even then, most of them won't be used and extension cords are going to be needed anyway with most tools being limited to a 6' factory cord. Then I push for one circuit per wall aside from the dedicated stuff. If he insists on one every 5' and a separate 20 amp circuit for each, I'll do it but it's a waste as far as I'm concerned. There's only so much that can be done at one time.

This is where my thinking landed. I have 2 circuits around my wood shop. A——-B———A———B
Almost all my machines are on 240 and fed appropriately. Almost all my power tools are battery or air. The stuff on 120V are the shop vac and bench grinder, router and miter saw. I’m a one man operation.

 

[partsguy5768]

I run quad boxes every 4 feet with the outlets in each box on a separate circuit. One cannot have enough outlets in a working shop!! I can be working by myself or up to six of us at a time so plenty of circuits also to supply needed outlets. Gfci??? Never in a shop as they are worthless. I wire up the absolute bare minimum to get final and then go to work wiring and finishing out the shop the first thing taking out and smashing the gfci ( did my last three this way) I love the look on a inspectors face as they are forced to final with a single light bulb and one outlet... I work / build my hot rods to lots of heavy equipment I own with tons of fab work etc.. lots of outlets, heavy circuits, no gfci are what is needed and wanted in a shop... I had a electrician wire my first garage when I was 23 ( 59 now) what a absolute joke!!!!! I told him big car guy need circuits and didn't want breakers kicking etc. Guess what I got? Pure ****. If in doubt go more and bigger and don't listen to the boloney of one guy using only one tool on a circuit at a time.......

 

[LopezBart]

Gfci??? Never in a shop as they are worthless. I wire up the absolute bare minimum to get final and then go to work wiring and finishing out the shop the first thing taking out and smashing the gfci ( did my last three this way) I love the look on a inspectors face as they are forced to final with a single light bulb and one outlet... I work / build my hot rods to lots of heavy equipment I own with tons of fab work etc.. lots of outlets, heavy circuits, no gfci are what is needed and wanted in a shop...

If this is a shop w/ employees, check your OSHA requirements and liability insurance.

 

[partsguy5768]

If this is a shop w/ employees, check your OSHA requirements and liability insurance.

Ahh no... and no... anyone that does " work" in a shop does not have a gfci on any circuit other then maybe a single outlet with a clock plugged into.. I'll take may chances on living a long life in spite of osha. I have contracted to the government for decades with one of my businesses and lets say anything the government does is not confidence inspiring safety wise or efficient... when wiring for potential shop use if in doubt "more" and "bigger" is better vs you can " only" do so much at a time or you only " need"....... there is nothing more frustrating in a shop environment then blowing breakers, tripping gfci, stringing tripping over drop cords, unpluging cords to plug something else in etc. Current shop I'm building 12 outlets on the outside alone for example... ( look close to each door) I did not build the house... 12 foot ceilings in the garage ( would be useful for a guy if he didn't have shop) and 6!!!!! Yes 6 single outlets in the entire garage!!! I keep 4 post lift for classic car storage ( 4 classic cars in the garage) how do you think this works out with 6 total outlets???? The electrician should be shot!!! For wiring up this **** fest. I have 400 amp of service in this garage... pic of the house.... budget wasn't a problem... this what you get when someone decides one only needs this many " circuits" stupid... add what you think you might possibly need and then go more..

 

[whateg01]

I can only operate a couple things at once, but I might want to plug in a big blower motor to move some air while I'm operating those two things. Example... Horizontal bandsaw while grinding burrs from the previous part on a day hot enough for a big fan but not hot enough to run the air conditioner (or maybe the door is open).

 

[beltfeed]

I wire a lot of pole barn shops. I find out where the dedicated equipment like an air compressor, chop saw, etc. will be, then have the customer tell me where else he thinks he needs receptacles. Then I try to talk him out of half of them while explaining how there is no need to have one every 5' because in this day and age with battery power prevalent, 10-15' spacing for general use is plenty and even then, most of them won't be used and extension cords are going to be needed anyway with most tools being limited to a 6' factory cord. Then I push for one circuit per wall aside from the dedicated stuff. If he insists on one every 5' and a separate 20 amp circuit for each, I'll do it but it's a waste as far as I'm concerned. There's only so much that can be done at one time.

This is a good point.

there is no need to have one every 5' because in this day and age with battery power prevalent,

 

[beltfeed]

this is what I had done on my power tool wall. Shop vac, drill press, miter saw, planer, sander. It’s probably overkill for my one man shop but I was coming from a garage space where if I ran the table saw and shop vac for dust collection it would blow the only circuit.

When doing AB circuits, it's really good to label receptacles for A or B.

 

[mm08822]

When doing AB circuits, it's really good to label receptacles for A or B.

Left / Right = A / B

 

[LopezBart]

When doing AB circuits, it's really good to label receptacles for A or B.

I really like the commercial practice of labeling each receptacle with panel and circuit breaker.

 

[beltfeed]

Left / Right = A / B

You know the deal. Create a label code for the circuit at the load center and also at the receptacle. Better now.

 

[whateg01]

I wire a lot of pole barn shops. I find out where the dedicated equipment like an air compressor, chop saw, etc. will be, then have the customer tell me where else he thinks he needs receptacles. Then I try to talk him out of half of them while explaining how there is no need to have one every 5' because in this day and age with battery power prevalent, 10-15' spacing for general use is plenty and even then, most of them won't be used and extension cords are going to be needed anyway with most tools being limited to a 6' factory cord. Then I push for one circuit per wall aside from the dedicated stuff. If he insists on one every 5' and a separate 20 amp circuit for each, I'll do it but it's a waste as far as I'm concerned. There's only so much that can be done at one time.

Yeah but nobody on GJ uses battery powered tools. It's "corded and air" or die! Those battery things will never catch on.

 

[RonnieC]

When doing AB circuits, it's really good to label receptacles for A or B.

Well I only had to test them once. A’s are on the left and B’s on the right. One man shop so I don’t need to communicate that to anyone.