Shop Outlet Placement/Voltage Advice

[Patrick Krekelberg]

Hi All!

We live on a remote homestead in the forest of Northern Minnesota. This Fall we started building a workshop which will also serve as an office/lab and studio for my business. I had planned to wire it myself, but have been too busy with work so I had a local company rough it in.

I have spray foam insulation scheduled for end of Jan so I want to make sure I've done my best to accommodate future flexibility. Just to clarify, I am starting from scratch with shop tools so I am building for the future rather than for things we actually own.

This is a 100A 30-breaker panel run from a farm pole which has 200A service. They ran 2-2-2-4 so due to the limitations of the wire it's on a 90A breaker. Our property was originally off-grid and I am going to be augmenting with solar over time.

I have more questions for you experts than I have space here, but here's a start:
* you will see I added 2 220's (one 30A the other 20A) in work zone 2 for tools and one in the mechanical room for a compressor (30A). They put the table saw outlet (30A) low on the wall but all others at bench height.
- Should I add some 110V outlets low, or do you think I will be OK with them all at bench height?
- Should I add another 220V in work zone 1?
- Where do you see a dust collector being mounted, even a make-shift one? Should I run a 220V up high for that somewhere?

* There is a lean-to on one side for a camper so I had them run an exterior outlet for the camper. It's just a 110V/20A outlet - do you think I should run 10ga to this so it can be a 30A plug for the camper?

Any other comments on this layout, things you would do before this is buttoned up? I am planning on drywall on the ground floor with French cleat along the walls of work zones 1 and 2, then getting wood from the local sawmill for the attic/studio floor, walls, and ceiling.

I realize I can't possibly know what all I will need to power in the future, so I am thinking of just having some conduit run from the panel out to the wall with a cap on it, so I can run surface mount conduit for any future things, like additional outlets on the ceiling or whatever. There is also 3/4" PVC running up into the attic above the panel.

Some specs:
* 30'x40' slab with a 12'x40' lean-to.
* 10' 2x6 walls
* Radiant heat in an insulated slab with a thermal break between the garage and hall/bathroom zones
* Navien combi boiler for in-floor heat, radiators upstairs, and hot water for the bathroom and an upstairs coffee station
* 18x8' insulated overhead door
* Windows from Thermo-tech and fiberglass entry doors from BayerBuilt (I try to buy local whenever I can)

Here is the overall plan, footprint being 30'x40':
Drummond Shop Ground Floor.jpg

This shows "work zone 1":
workzone1.jpg

This shows "work zone 2":
workzone2.jpg

here is the exterior (historic cabin in background I hope to restore):
IMG_0757.jpg
IMG_0763.jpg

[Malcolm McLeod]

... so I am thinking of just having some conduit run from the panel out to the wall with a cap on it, so I can run ... any future things, like additional outlets ...

^This...

Run conduit to 4-square boxes set at appropriate depth for your intended wall finish, run a pull cord (strong twine) in the conduit, cover the box, and then insulate. Put them anywhere you think you might need another circuit.

Me'll let other un's more smarter then I, tell you the best size conduit, but with 1/2" you can run 1-ph/240V wire to nearly anything short of 10Hp. And if you ever need to add a circuit, or swap 120V<>240V, it's easy to pull the right wire in.

And welcome to SMC.

[Patrick Krekelberg]

Run conduit to 4-square boxes set at appropriate depth for your intended wall finish, run a pull cord (strong twine) in the conduit, cover the box, and then insulate. Put them anywhere you think you might need another circuit.

based on what you see, where do you think I should put them? "Work Zone 2" is obviously the easiest place to get to since it shares a wall with the panel, and it's purposefully spaced out from the "garage" part. I am expecting to figure out a way to always be able to access the attic. It'd be tougher to get conduit to "Work Zone 1".

Since I am thinking of putting a compressor in the mechanical room I'm trying to figure out a way to have maybe a 1x1' boxed raceway from the mechanical room, over the bathroom ceiling in the attic through to the garage area for future power/air/whatever. Haven't figured out what that should be made out of, yet.

And welcome to SMC.

thank you!

[Jim Becker]

You absolutely should pre-wire for a dust collection system (separate circuit) and my recommendation is for it to be 10 gauge so you can do either 20 or 30 amps by just configuring the terminations. My suggestion is that you also plan for your dust collection system to be in the same mechanical room as your compressor so you can sound-deaden it and run a bent air return to the shop from there.

[Brice Rogers]

In a forum like this, every one has their own ideas. Some of which may be good for you and some which don't make as much sense.

When I wired my workshop, I made all of my wall receptacles at bench height, because I wasn't sure where in the next few decades I would be putting a bench. I also wired them with 12 ga. and used 20 amp breakers for the outlets. It turned out to be a good idea. I also put in more receptacles than a house would normally have. Most are quads and are six feet apart. So, I spent perhaps an addition $50. But I have never regretted it. I also put in some overhead lines with receptacles and drop lines for things like freestanding tools (grinders, belt sander, bandsaw, etc.) It is nice not to have to step over a cord. I made sure that my lights were not on the same circuit as a tool. I also made it so that I had three lighting zones. No sense lighting the whole place up if I'm only going to work in one part.

I ran a few spare lines "just in case". Then, 15 years later I used two of them for small window AC units and the third one for a dedicated 240 VAC line to my wood lathe.

[Brian Henderson]

You absolutely should pre-wire for a dust collection system (separate circuit) and my recommendation is for it to be 10 gauge so you can do either 20 or 30 amps by just configuring the terminations. My suggestion is that you also plan for your dust collection system to be in the same mechanical room as your compressor so you can sound-deaden it and run a bent air return to the shop from there.

Exactly what I was going to say, it is so much more convenient to put the DC and compressor in the same external room separately wired for the two. it isn't hard to sound proof and you don't have to listen to the two loudest machines in the shop.

[Bill Dufour]

The outside camper outlet I would up it to 50 amps 240. that will allow you to use a proper welder outside. Or a hottub. At the very least make it 30 amps 240. for a small mig welder.

[Bill Dufour]

30x40 shop I would have a subpanel on the wall, probably opposite the service panel. Check Craigs list for heavy wire and used panels if allowed.
It is nice to have some outside outlets for saws, lights etc. Do you need an attic fan? split ac, heater. My shop exterior lights are switched from inside the house so I do not have to walk in the dark to the shop.
My supply to the shop is wire from craigs list that is more then 20 amps oversized for the breaker supplying it. To buy wire from the Borg would have cost more then $100 even including the slight extra cost of bigger conduit. If you like your existing breaker panel buy the same make and you can trade breakers around as long as you use the correct wire sizes. Also makes testing easier as you can swap in a known good breaker.
Bill D

[Bill Dufour]

do not forget wiring for phone/tv/internet/ alarm, thermostat.
Bill D

[John Lifer]

All outlets Quads. Makes it Way easier. Costs you a couple of bucks more for the box and additional outlet and cover. Big deal. DO IT! you won't regret it! And where every you think you might need outlet, DO IT NOW! Way easier and cheaper up front....

[Patrick Krekelberg]

All outlets Quads. Makes it Way easier. Costs you a couple of bucks more for the box and additional outlet and cover. Big deal. DO IT! you won't regret it! And where every you think you might need outlet, DO IT NOW! Way easier and cheaper up front....

Yeah, I am heading to the hardware store now. The electrician already finished a basic rough-in and I had way too much going on to keep an eye on details like that unfortunately... so they are all single gang. Lots of them, but single gang. I am going to add some double-gang boxes and a few other bits.

[Jim Becker]

I see the "do quads" thing quite often here in the forum, but have only found one particular outlet in my shop where more than two receptacles was needed. I don't leave portable tools plugged in when they are not in use so other than chargers for battery operated tools in that one spot, duplex has been just fine. Don't sweat it if your shop has mostly duplex...it's not likely to be an issue long-term.

[Jim Finn]

I would , and have, put all electrical wiring in conduit outside the wall. MUCH easier to change in the future. Install all fourplex outlets. Best thing about my small shop is that I have a toilet in it. The older we get the more important this is.

[Brian Henderson]

The nicest thing about my new shop is the outlets that were already in place. I have no idea what the previous owners used it for but there are outlets about every 4 feet all the way around, plus 4 220 outlets at regular intervals. The only thing I had to do was install 220 out in my extension for dust collection and compressor.

[Bill Space]

“They ran 2-2-2-4 so due to the limitations of the wire it's on a 90A breaker.”

Curious. Is this a three phase feed? Or a typo?

Normally a single phase feed uses three wires...