Finally! Bigger shop space coming! Wiring question...

[TomFromStLouis]

My 20x25 garage shop has a single overhead quad outlet with a single retractable extension cord overhead and I wish I had more of each

[fredhargis]

I'm on my third free standing shop, and all 3 of them had 100 amp sub panels....none of them were ever short on supply.  I wouldn't suggest dedicated circuits for the saw (is it 5 HP?) but certainly for the DC you want it dedicated. Other than that, I agree with the wall receptacles being 52" high, have ceiling outlets (both 120V and 240V) more or less centered in the area. I'm guessing the 240V outlets will be 20 amps, but it might not hurt to have a couple of 30 amp outlets, put the DC on one (just in case it gets replaced with a bigger unit) and maybe one other. Lastly, congrats on the step up; and don't over think it...just enjoy!

[®smpr_fi_mac®]

I'm in the same boat as you right now; I'm planning the wiring in my garage shop (2-car garage with one, maybe two bay(s) blocked by stationary tools).  The walls are still bare studs, so I have lots of freedom like you.  I'm following much of the advice given above (I asked this same question several weeks back).

My plans are:

• Pay an electrician to install a 150 amp box in the garage.  Mains are a pair of 150 amp boxes in the basement.  Then I'll do the rest myself.
  
• Five (5) 220V circuits, supporting nine (9) outlets.  The stand alone will be for a future DC.  The others will support my five (5) current 220V pieces; I'll likely add two (2) more pieces in the future.
  
• At *least* twenty (20) 120V, 20 amp, 4-gang outlets on five circuits.  My shop's dimensions are 22x22' feet.  Lots of outlets on each wall.
  
• At *least* six (6) LED shop lights on the ceiling.  Four (4) in my section of the garage/shop, and two (2) over my wife's bay, where she'll park her car.  A future wall will mostly divide hers from mine.
  
• My ceiling is 12' high, so I won't be using drop-down extension cords.
  
• Two 120V (2) outlets in the ceiling on one circuit to support a pair of air scrubbers.
  

This should be over kill for my needs running a one-man hobby shop, though my wife's cousin will likely be over often using it; we may work together at times.  If I find that I need more outlets after putting in insulation and drywall I'll run external conduit as needed.

[Admiral]

I have your basic 3hp unisaw, 2hp Jet dust collector, 19" 3hp bandsaw, 8" jointer and 15" planer, all 220, and just have two 220 20a circuits, one on each opposite wall, with three single outlets on each circuit.  I regularly run the TS and dust collector on the same circuit with no problems.  I have three 120, 20a circuits, one on each wall (with GFI outlets) and one on the ceiling for lighting; 7 double outlets on each wall.  100 amp sub panel.  I had an electrician put in the subpanel as at the time I felt uncomfortable doing it, but I wired the rest myself.  It's been 16 years and I've never blew a braker, and have more than enough available outlets.

[plharrison]

Great advice guys; thanks much. That gives me a lot more to think about.
Paul

[rwe2156]

Unless you have quite a few big machines, or central AC, etc. 150A or 200A is total overkill. Not only that, they would require a separate service to the house which is several $1000.

100A will do it. You can run it as a sub off your main panel (if you have room) Actually, I ran my whole shop off a 60A subpanel for 20 years.  This included 20 8' tube lights, numerous fans, DC, 2 & 3HP machines, refrigerator, window AC unit - even a 5HP compressor.  Never tripped a breaker once.

For 240V machines  3HP or less you can run them all on 1 circuit with daisy chained outlets.  However, this may not be code in your area so check with an electrician.

I suggest several 120V circuits: 1 for lighting, 1 for hand power tools, dedicated circuits for larger 120V machines or DC. Its also nice to have a few hanging cords from ceiling over assembly table, etc. Check with an electrician.

I recommend outlets 4' off the ground spaced every 4'.  This is not expensive to do and will give you lots of flexibility.  An electrician can advise you on this.

I think surface mounting in conduit is the way to go. This gives lots of flexibility in changing/adding circuits or outlets/switches.

Did I mention get an electrician? :-)

 Good luck with your new shop.  Dust control and ventilation are critical with a basement shop so you may need to address issue of sawdust getting in house.

[TDKPE]

You need separate circuits for each machine that will run concurrently with another machine (or other load), like the TS and the DC, which will run under load at the same time.  You don't need a separate circuit for things that will never run under load concurrently, like the TS and the RAS, assuming you're the only one in the shop working them.  It's not a commercial or industrial installation, after all.

Putting more than one receptacle on a machine tool circuit is fine, and will cut costs in a big way.  I have only one 240V 20A circuit for all my big machines.  The cyclone is on its own circuit.  Lighting, of course, is on a dedicated circuit, and I only have two 120V general-purpose receptacle circuits for everything else.  One of them was originally for a portable electric heater, which it turns out I didn't need and never use (basement shop, so it's a little chilly down there most of the time), so it serves my utility bench with chargers and power supplies and soldering irons and junk like that.  Two 20A circuits serving quad boxes with left/right duplex receptacles (don't really need color coding, as long as left/right is consistent) on different circuits would be the nuts for me, but to be honest, I've never had to tap off the bench circuit when running 120V machines, even with the air cleaner running.  Now, if I had a 1 or 1.5 hp BS that I was pushing hard, then a 20A 120V circuit wouldn't be able to handle that plus something like a big air cleaner, but my 120V machines aren't that big.  Your situation may call for more 120V circuits to support larger motors running concurrently.

At the very least, have your electrician put a sub-panel in the shop, and leave the branch circuits for later.  You will rearrange your shop a bunch of times, so do plane for being able to move your stuff around.  That's why I have six 240V receptacles for three machines - I tend to move things around as needed in my cramped space, and having a branch circuit for each one of them would be just a waste of money.  If you end up wiring up a 30A tool circuit, do it with an eye toward where that machine may move to in the future, or at least, that it might move, and make sure you can extend or modify the circuit in the future, including adding another receptacle.  You may not use both of them once you add a second, but you may end up with the machine back where it started.  Keep flexibility in mind.

[bhh]

Suggest also to identify 120v circuits by using different colored receptacles, such as brown, ivory, and white.   This makes it easy to divide simultaneous heavy loads such as a planer and shop vac which when used together can trip a breaker.  Also more than one lighting circuit.     Prevents working in dark if one circuit is off when your working on it.   Roly

I have some plastic tape in different colors.   I simply cut a 1" piece of tape and put it on the face plate.   One circuit is red, another is green, and so on.  On the first in line with GFCI, I also wrote in Sharpie what breaker # it was.

[DFJarvie]

Remember to put a few outlets around the shop on the outside should you need power for a weed wacker. Also add an outlet right by the door on the inside so you can run any extension cords should you want to clean your car, etc.