It's ok, but imo as discussed earlier, it's way overkill for a home shop
unless you've got some _serious_ 240V gear, here to run a completely
independent circuit for every tool. It would take something approaching
a 5hp motor to draw 30A assuming only 50% overall efficiency and that
would have to be at full output; rarely does a tool require that. And,
breakers are designed to handle the short-term surge of a starting
current so it's not like that's a real problem, either. Plus, there's
the factor of how many of these tools can/will you be using at a time as
And again, unless you're hardwiring the tool (dispensing w/ the
cordset/plug) the non-fused disconnect _is_ the plug; there's no need
for anything any fancier in a home shop and particularly if it's a
garage it could be quite inconvenient to have them essentially
Comes down to what are you really wiring here--a home shop or a
commercial business shop kinda' thing? Of course, if $$ is no concern,
go for the gold...
$0.02, imo, ymmv, etc., etc., etc., ...
You did a pretty job assessing my situation earlier--it was kind of you to
go out of your
way to write that the OP probably wasn't setting up shop for a commerical
Borrowing a title from Hemmingway, I am after "A Clean Well-Lighted Place",
and a place
where I can build some of the things I would like to build. Paraphrasing
wrote, "a place with a captain's seat" (too). I actually have one of those,
but it is surrounded
by books and there is no room for sawdust there.
I spent 20 minutes walking meditatively around my "Untidy Mildy-Lit Place"
with a measuring tape. I noted, sort of proud of my new knowledge, that I
someone had moved an overhead light to 37" in front of the main panel--it
had evidentally been in the
space described (roughtly) in the NEC as "that space, 36" outward from the
30 inches wide, open to the ceiling and to the floor that must remain free
I noted violations of this policy that were not found during our house's
It won't matter now though because lots of stuff is coming down--kitchen
cupboards (that look hideous),
all the wall board on at least one wall--the matter of a few feet of wire is
240v DC, TS, and Air Compressor, none of which I have, merit their own
circuits. Tools on 120v circuits
can afford to do more sharing since probably only one will be powered at a
Q) ShouId I leave a few inches of the wallboard around the main panel and
existing outlets and switches
(which will remain live) for any reason? BTW, I imagine it will take some
accurate measuring to
cut wallboard to fit my panel and subpanel (and outlets, etc). I noted that
it will requires 2 pieces to
fit around a panel. Going this far, I might as well add insulation to this
wall too. Concerning the wall without the
panels, I ponder whether I need to put any wallboard back up. --I obviously
need to get one of those
wiring books so I don't become an "electrical-pest" around here!
After my 20 minute inspection, I came in from my shop-to-be feeling a little
wiser, a little readier, and with the
suspicions that I'm getting read to make the biggest mess I ever made! : )
I will have to
to cut everything into small pieces so my refuse company will haul it away
week by week in the usual can.
That effort will probably more than pay for any wire I use.. : ) I'll
decide more after I find how much it cost
this weekend! ; )
The main thing in running your circuits at this point is to get good
wiring in the walls. As was stated don't run less then #12. If in
doubt for the future run a 12-3 or 10-3 wire set up and cap the unused
wire. In the future if you need to have 240 at a outlet you have the
extra wire. Depending on your construction its wise to install some
conduit, flex or smurf tube to be able to pull additional circuits,
cable or phone lines. If you have an accessible attic a lot of this
can be done as risers for future use.
Mike, Thank you for some very good ideas!
I DO HAVE an accessible attic, and I believe that most, if not all, of
the wires from the main panel go right up to it. I had been debating
with myself whether to wire "through the attic" or through the studs.
One factor is that the wall I wish to add the outlets to first tops out
at the eaves. I thought that a combination would be easiest--attic to a
wall, down, and then through the studs. No NEC violations in sight,
right??? Anything to be wary of (the attic is not living space)?
Do you agree that this makes sense, even if I have to rip down a bunch
of wallboard to do it?
I would do most of it through the walls just because its easier on
your body. The main reason to run extra pipes to the attic is for
the future needs that always come up so that you don't have to cut the
wall covering.. A combination would be fine as well. Just remember
to protect the wiring if your using sheathed cable or anything that
could be punctured by a screw or nail. Another point that others have
brought up is the advantage of keeping your outlets above 4' so they
don't get covered up by sheet goods leaned against the wall.
I'll have to read up on the right way to approach this. Thank you for
mentioning it! To me %-), It seems like the best protection is to know
where the wires are. I read a suggestion somewhere to "sketch the
layout of the wires". What sort of protection are you thinking of--I
assume something that would lie in the attic rather than through the studs?
If thru studs, place holes in center to maximize distance from each side
to the cable(s). They make metal stud plates to put on the face of the
stud over the hole location that are stout enough to tell installer
"don't do that" when hanging sheetrock, etc. I 16d w/ a 20oz framer or
pneumatic gun won't be phased, but there's little likelihood of that in
When running cable vertically in the cavity, it's to be fastened at the
box and then keep it in the middle as well. A hollow cavity it can just
be loose as then there's no restriction such it'll just move. If
insulating, again keep it in the center of the stud and staple just to
get it out of the way for insulating and you're good to go.
Surface mount is another issue, but doesn't sound like you're intending
any of that...
All above, of course, assumes you're not somewhere like Chicago that
local Code requires BX still or some other silliness...
If going through studs, get some of those metal protective plates designed
to protect the wiring. Just pound themon the stud and they are covered.
If going in the attic, realize over time that the wiring can get buried
indust, etc. Ihave seen a couple attic wiring jobs that placed the wiring up
in the air on boxes or had some kind of bright , warning type of ribbon
around it. The idea is that if you don't go up therre for five years, you
will have no problem finding the wires and working on them.
Along those lines, a wiring diagram, laminated in plastic, and tacked up
where you can see it would be nice as well.
A wiring diagram like that would be great! I made it part of my
counter-offer that the sellers
label the 2 dozen circuit breakers in the main panel (and I'm glad I did)!
There's one for each ceiling fan, the sump pump, and the list goes on...
The wires are not labeled.
The "bright warning ribbon" idea you mentioned seems very good. I'll make
labeling process part of mapping out what I'm dealing with.
I stll haven't made that long trek accross all of the joists yet (though the
of the attic). My neighbor fell through his ceiling on one of his first
Why worry, I guess, it's only drywall! The house-inspector trotted right
Another thing I like to do it to use a permanent marker to write the
circuit breaker number associated with each outlet or switch in an area
next to each so that it's covered by the outlet cover/switch plate. It
makes things a little easier when it becomes necessary to replace an
outlet or switch.
Yes! In fact, what would be wrong with having some obvious standard marking on
switch plate and outlet in the house that says exactly which breaker it's tied
to? How many
times have I done some wiring work and had somebody at the far end of the house
yell to me
that I've finally turned off the correct breaker after trying three or four
usually have to reset every clock in the house after that happens. :-)
See Nad. See Nad go. Go Nad!
To reply, eat the taco.
Digital camera ...
... put the pictures on a CD, keep it as a reference, then give it to
the next owner. It's what I do for all electrical, mechanical and
plumbing rough-ins, and even framing, blocking, and shear wall nailing
Been doing it for years, and the simple practice has saved literally
tens of thousands of dollars in re-do's.
Like dpb said they make a nail plate. If you have 2x6 studs the
center should be ok. Its also a code thing for 2x4's. On commercial
jobs we labeled every box with what panel it was fed from and which
circuits are in it.. Reommend the same for your shop. You can skip
the panel id as you'll know it but labeling the breaker number on a
receptacle can save you time. Used to do a lot of work for Kenworth
truck and they maintained a cad drawing of the entire electrical
system. We were assigned circuits and panels for what we were
installing and labeled every junction box with the information.
Labeling the receptacle is a great idea! It's easy to take the cover off
and check for an ID then turn the breaker box off. I'm never sure if the
breaker will turn off the stairway light as well as the basement lights,
but if the receptacle was marked I'd know for sure. (Naturally, I'd
still test. It'd just save me a few trips to the breaker box.)
Never teach your apprentice everything you know.
Again, I ask...how large a DC, TS and compressor to you really envision
having? Look realistically at how much current those are drawing an
compare to 30A...
I'm not saying you should have only one, I'd surely recommend at least
two but I'd definitely not be putting only single-dedicated outlets on
each for a dedicated purpose.
But you certainly are correct in that while you're doing major work the
cost of an additional circuit or two including the breaker isn't huge...
I'd cut back evenly to mid of adjacent studs for a matching
location/seam to have a solid edge if the box is on top, otherwise if
it's a major reno, it's a whole lot easier to just pull it all out and
start from scratch. In a garage they may have used a plywood backer
(which I like). And, surely now is the time to insulate as well...
It's not that I thought these tools would exceed the load--I just
thought their induction motors would "prefer it" if they were are
dedicated circuits, much as I assume they would prefer to run on 240v
rather than 120v. My BS, for instance, can run on either. It is
definitely possible that my concern about this is undue--for I only
know from what I read and my intuition.
Since the current main panel was put in as a repair 3 years ago (hail
damage),and the wallboard was not replaced at that time, the wallboard
and the panel do not fit together "like new". There are 2 or 3 small
missing-wallboard gaps 1/4" wide and about 2 inches long. Hardly a big
deal, but I may as well make it look like new, especially if I'm
installing the sub-panel right next to it. Since I do not see a backer
board in front, I assume there is one in back--as you suggested!
I almost hate to admit it but I am sort of excited about taking on some
of these new challenges. Probably a couple hours of crawling around the
attic will help me to curb some of my enthusiasm. Thank you for your
help and for providing me with a few valuable insights today!
I imagine I'll spend a bit more time learning about all of the details I
need to know (clamping, review codes, etc) and then eventually wire
"everything" in about 2 days. Realistic?
Indeed, for such small motors as one is talking about here (and, yes,
5-10 hp is, indeed, "small") there's nothing going on that they'll have
any clue (if they were, indeed, sentient as a metaphor :) ) whether the
others are on the same circuit or not.
As for the 240V/120V, it's essentially the same; the only _real_
difference is that you halve the current at 240V which allows for the
wiring to be at smaller gauge service to accommodate load instead of
even more multiple circuits or larger wiring w/ its attendant higher
cost and especially if were to go above #10 it's a lot more work/effort.
So, if that's the reason you've been talking of single circuit for every
machine, you're definitely heading down the path for the wrong reason.
Again, not saying it's wrong to do so and overkill is better than under
for future unanticipated desires, but there's a limit of "enough's
enough" for just a casual shop.
As for the aesthetics question, given what you've described, I'd
probably dismount the box and clean up behind/around it at the same
time. Of course, if this is the primary feed panel, remember it's live
unless there's an outside disconnect or the meter is pulled while you're
As example, while it's intended as sorta' temporary (altho it's now been
10 years :) ), when returned to the farm and brought the ww shop w/ me,
I wired an area in the barn that had been used as seed wheat bin for use
as a shop. I added one 30A 240V circuit and one 20A 120V.
On the 240V is the PM66 TS, Delta 8" jointer, Delta 13" Model 13 (the
old industrial style weighs 300+ not a lunchbox) and the DC and A/C
(80-gal upright). I've never had even a flicker in use, what more trip
the breaker for a startup load. The A/C was on another circuit but it
was physically moved during the barn rehab project when needed to
replace the west end floor sill plate since it was in the way and
plugged into an extra outlet in the shop and I've never got around to
putting it back where it was (and that's been approaching 5 years by now
From what you've said your ambitions are I can't imagine you'll have
anything exceeding the above...
HTH w/ perspective.
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