OH

"Otto Hoel"

03/01/2004 7:48 PM

Number of outlets per circuit in new shop

I'm converting my small two car garage into a shop. I now have only two
outlets in there plus the light circuit for the ceiling lights. I would
like to put in a bunch of 110V outlets for handheld power tools, movable
lights, and such things. What I cannot find out is how many outlets I
should have per circuit when I don't know what the load is going to be? Is
there a "rule of thumb" somewhere, or a "best practice" kind of thing that I
can use as a guideline? I need this both for the 110V outlets and the 220V
outlets since I'm planning to leave some open for future tools. I will
convert all my tools to 220V that can be converted , but I need to plan for
expansion. Or should I just run a separate circuit to each 220V tool?
Since I'm the only one working there, only one tool will be used at a time,
but the DC and the A/C unit, both 220V, will be running.

My shop is 20' x 20'. The main CB in my current panel says 150 so I assume
I have 150Amp service. Otherwise no labels or markings clutters up the
expanse of gray paint in the panel, so I guess my first job should be to
map out the circuits I already have. And finally, the panel is full. No
expansion possible. So I will have to put in a sub panel. I have room to
put it right next to the existing panel. Unless that is a no no.

Otto


This topic has 7 replies

cC

[email protected] (Charlie Self)

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

04/01/2004 1:06 AM

Otto Hoet asks:

>I'm converting my small two car garage into a shop. I now have only two
>outlets in there plus the light circuit for the ceiling lights. I would
>like to put in a bunch of 110V outlets for handheld power tools, movable
>lights, and such things. What I cannot find out is how many outlets I
>should have per circuit when I don't know what the load is going to be? Is
>there a "rule of thumb" somewhere, or a "best practice" kind of thing that I
>can use as a guideline? I need this both for the 110V outlets and the 220V
>outlets since I'm planning to leave some open for future tools.

I think the number was, may still be, 8 for 110 circuits. I really didn't check
on 220 because I put only 1 on each (aslo didn't run 8 on each 110: 6 was
plenty).

>The main CB in my current panel says 150 so I assume
>I have 150Amp service. Otherwise no labels or markings clutters up the
>expanse of gray paint in the panel, so I guess my first job should be to
>map out the circuits I already have. And finally, the panel is full. No
>expansion possible. So I will have to put in a sub panel. I have room to
>put it right next to the existing panel. Unless that is a no no.


Subpanel should be fine, but check locally. You might also be able to use half
thickness breakers, thus getting twofers--two breakers in a single slot.

Charlie Self
"If you want to know what God thinks of money, just look at the people he gave
it to. " Dorothy Parker

http://hometown.aol.com/charliediy/myhomepage/business.html

Sk

"Swingman"

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

03/01/2004 8:22 PM

http://theoak.com/rick/Electricity_in_the_Shop.html

Probably more than you want to know at present, but keep track of the url
because most of it will eventually come in handy in a shop at some point.

--
www.e-woodshop.net
Last update: 1/02/04

"Otto Hoel" wrote in message

> My shop is 20' x 20'. The main CB in my current panel says 150 so I
assume
> I have 150Amp service. Otherwise no labels or markings clutters up the
> expanse of gray paint in the panel, so I guess my first job should be to
> map out the circuits I already have. And finally, the panel is full. No
> expansion possible. So I will have to put in a sub panel. I have room to
> put it right next to the existing panel. Unless that is a no no.

gG

in reply to "Swingman" on 03/01/2004 8:22 PM

04/01/2004 4:54 AM

>http://theoak.com/rick/Electricity_in_the_Shop.html
>
>Probably more than you want to know at present, but keep track of the url
>because most of it will eventually come in handy in a shop at some point.

That's pretty good stuff. My only comment is about sub panels.
You DO put in the extra grounding bus (usually purchased separately)
and DO NOT install the green bonding screw if this is a sub panel in the same
building as the main ... no exceptions. Ground and neutral must be separate.
You will be bringing over a 4 wire feeder 2 phases, an insulated white neutral
and a ground. The ground bus attaches directly to the enclosure. There will be
tapped holes for this.

There are conditions in a sub panel in a separate building where you can
reground the neutral and pull a 3 wire feeder but that is still not the usual
way to do it.

OH

"Otto Hoel"

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

04/01/2004 4:44 PM

Thanks Charlie, that was just what I wanted to know. I've got some twofers
already and I'll look into if they can be used for the rest, but unless I
can get everything into the existing panel, I'll have to get a new one
anyway. Which is what I suspect, but I got an electrician at work and I'm
going to pick his brain about all this too.

And ol' Ms. Dorothy is one of my all time favorites. Glad to see you
finally got around to her in your sig line :)

Thanks again

Otto

"Charlie Self" <[email protected]> wrote in message
news:[email protected]...

> I think the number was, may still be, 8 for 110 circuits. I really didn't
check
> on 220 because I put only 1 on each (aslo didn't run 8 on each 110: 6 was
> plenty).
>
>
> Subpanel should be fine, but check locally. You might also be able to use
half
> thickness breakers, thus getting twofers--two breakers in a single slot.
>
> Charlie Self
> "If you want to know what God thinks of money, just look at the people he
gave
> it to. " Dorothy Parker
>
> http://hometown.aol.com/charliediy/myhomepage/business.html

OH

"Otto Hoel"

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

04/01/2004 4:37 PM

Great link, and added to my favorites.
Thanks

Otto

"Swingman" <[email protected]> wrote in message
news:[email protected]...
> http://theoak.com/rick/Electricity_in_the_Shop.html
>
> Probably more than you want to know at present, but keep track of the url
> because most of it will eventually come in handy in a shop at some point.
>
> --
> www.e-woodshop.net

CR

C

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

04/01/2004 3:57 PM

On Sat, 03 Jan 2004 19:48:02 -0500, Otto Hoel wrote:

> I'm converting my small two car garage into a shop. I now have only two
> outlets in there plus the light circuit for the ceiling lights. I would
> like to put in a bunch of 110V outlets for handheld power tools, movable
> lights, and such things. What I cannot find out is how many outlets I
> should have per circuit when I don't know what the load is going to be? Is
> there a "rule of thumb" somewhere, or a "best practice" kind of thing that I
> can use as a guideline? I need this both for the 110V outlets and the 220V
> outlets since I'm planning to leave some open for future tools. I will
> convert all my tools to 220V that can be converted , but I need to plan for
> expansion. Or should I just run a separate circuit to each 220V tool?
> Since I'm the only one working there, only one tool will be used at a time,
> but the DC and the A/C unit, both 220V, will be running.
>
> My shop is 20' x 20'. The main CB in my current panel says 150 so I assume
> I have 150Amp service. Otherwise no labels or markings clutters up the
> expanse of gray paint in the panel, so I guess my first job should be to
> map out the circuits I already have. And finally, the panel is full. No
> expansion possible. So I will have to put in a sub panel. I have room to
> put it right next to the existing panel. Unless that is a no no.
>
> Otto


Is it a 1-man shop?

If so, you certainly don't need as many circuits as you might think. The
reason: You aren't going to have everything running at once.

Your best and most accurate source for info will be the local electrical
inspector. It's better to do things right than to burn down the place or
to later deal with an irate inspector.

This does not mean you can't do your own wiring. Homeowners generally can.

Electrical permits are cheap.

Electricity can be friend or foe. It's great but nothing to take lightly,
especially if you have any doubts whatsoever. There are many knowledgable
folks prowling newsgroups with all levels of expertise. How do you know
which to choose?

Again, talk to the electrical inspector. Ours is also the local building
inspector, a good place to begin.

CR

C

in reply to "Otto Hoel" on 03/01/2004 7:48 PM

04/01/2004 3:58 PM

On Sat, 03 Jan 2004 19:48:02 -0500, Otto Hoel wrote:

> I'm converting my small two car garage into a shop. I now have only two
> outlets in there plus the light circuit for the ceiling lights. I would
> like to put in a bunch of 110V outlets for handheld power tools, movable
> lights, and such things. What I cannot find out is how many outlets I
> should have per circuit when I don't know what the load is going to be? Is
> there a "rule of thumb" somewhere, or a "best practice" kind of thing that I
> can use as a guideline? I need this both for the 110V outlets and the 220V
> outlets since I'm planning to leave some open for future tools. I will
> convert all my tools to 220V that can be converted , but I need to plan for
> expansion. Or should I just run a separate circuit to each 220V tool?
> Since I'm the only one working there, only one tool will be used at a time,
> but the DC and the A/C unit, both 220V, will be running.
>
> My shop is 20' x 20'. The main CB in my current panel says 150 so I assume
> I have 150Amp service. Otherwise no labels or markings clutters up the
> expanse of gray paint in the panel, so I guess my first job should be to
> map out the circuits I already have. And finally, the panel is full. No
> expansion possible. So I will have to put in a sub panel. I have room to
> put it right next to the existing panel. Unless that is a no no.
>
> Otto


With the outlets, include a fire extinguisher, a great addition to any
shop.


You’ve reached the end of replies