I don't have any big tools yet other than an arc welder, but I am wiring my
shop now and want to be 220v ready for when I do. I don't envision a
motor larger than 3HP, so figure I will run 10/3 cabling for all but arc
welder where 8/3 will be run.
My question concerns how to best stub out the box and recepticle? Should
I use 2x4 or 4x4 boxes and is there a standard recepticle than most 220v
woodworking tools use? If so, what would the markings be such that I can
find it at the building store?
I standardized on a NEMA 6L-20 locking plug & outlet for all of my 220V tools.
It is a twist-lock 3-wire connector.
All of my 220V tools came without a plug. If any of yours come with a plug,
its easy enough to cut the plug off and put on a 6L-20.
You could use a 6L-30 for your welder.
A 6L-20 female outlet will fit a single-gang box. I think a 6L-30 will, too.
If you decide that a 6L-20 is way too expensive, try a normal 20 amp
plug and outlet. They look just like regular plugs except the tines
are horizontal rather than vertical. You can get them at Lowes or Home
Depot for less than 1/4 the price of the 6L-20.
My unisaw came with this connector as did my dust collector. You can
use a standard 2x4 outlet box and just get a cover with single round
I would do it two ways....
(1) 120v in the wall outlets (use the four outlet boxes)
(2) ALL 220 in plastic conduit surface mounted.
(3) Stick with a very common plug and receptacle for all
of the 220v (6L-20)
I suggest the conduit cause it is MUCH easier to move or
add on to when you start moving things around. I have 220
outlet about every 6-8 feet.
Jonathan Mau wrote:
On 8 Sep 2006 12:56:46 GMT, snipped-for-privacy@FreeNet.Carleton.CA (Jonathan Mau)
If 3 HP is the largest you're going to run, you need not go bigger
than 12/3. If you're going to wire 10/3, you'll be able to run a 5 HP
If you insist on 10/3, do NOT try to use a 2x4 box. You will be very
sorry trying to maneuver that thick wire around in that tiny space.
The 6-15 series (two horizontal blades plus a ground) seems to be the
defacto standard on machines equipped with cords and plugs.
Jonathan Mau wrote:
> I don't have any big tools yet other than an arc welder, but I am
> shop now and want to be 220v ready for when I do. I don't envision a
> motor larger than 3HP, so figure I will run 10/3 cabling for all
> welder where 8/3 will be run.
> My question concerns how to best stub out the box and recepticle?
> I use 2x4 or 4x4 boxes and is there a standard receptacle than most
> woodworking tools use? If so, what would the markings be such that
> find it at the building store?
When it comes to planning an electrical distribution system, "bigger
is better" is a good approach.
I'd plan on at least one 2P-40A circuit using #8AWG for a future air
Use 2 gang (4x4) boxes for all receptacles, you will appreciate the
space when it is time to make connections.
I have standardized on 30A locking devices for all 240V equipment
connected with #10AWG wire.
Certainly not required for every machine, but it makes life simple.
You've had some good responses (some not so good). To answer your direct
question, "is there a standard receptacle than most 220v woodworking tools
use? If so, what would the markings be such that I can find it at the
No, there seems to be no standard. I too converted all of my 220v tools to
NEMA 6L-30 locking plugs. Welders, table and bandsaw along with the dust
I used EMT conduit and 5S boxes and covers. All wires were individual THHN
wires. I would avoid the 10/3 or 8/3 wrapped cables. They are harder to
pull and more difficult should you need to split up or add too should you
need (and you will) make changes.
I have used this setup now in three shops and have never regretted it.
I always use 4x4 boxes, even for single devices (using a plaster ring).
Gives plenty of room in the box for splices.
Standard recept is a NEMA 6-15R or 6-20R. You might wish to consider
using NEMA L6-15R or L6-20R (twist-lock).
On Fri, 8 Sep 2006 06:56:46 -0600, Jonathan Mau wrote
Bigger IS better.
You'll hear all sorts of advice on wire size, etc. but for a box it is best
to use as large (cubic inches) as you can fit. I'd go with a 4x4 metal since
the size allows room for al the wire connections etc. and metal since it'll
avoid (or at least reduce) thread issues. You only are doing a few versus
dozens used in a typical house so cost savings isn't really an issue.
Jonathan Mau ( snipped-for-privacy@FreeNet.Carleton.CA) writes:
Thank you for all the replies. I especially appreciate the link to the
leviton table which shows all the plug types.
A quick supplemental question. When you folks say to use a 4 inch box,
you are referring to the type that a dryer recepticle typically uses, and
not a double regular so to speak. I believe the former only takes a metal
cover plate whereas the latter takes all the usual plastic covers.
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