New shop wiring plan and questions

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Forum topic by Stacey posted 02-20-2008 10:04 PM 9848 views 0 times favorited 5 replies Add to Favorites Watch
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19 posts in 3754 days

02-20-2008 10:04 PM

Thanks again to everyone who offered advise for my shop lighting. I picked up my fixtures today and will end up running 3 rows of 8’ T8s the length of my shop. Very exciting to finally be able to see in workspace!

Now on to the shop wiring. The shop is 18’ x 32’ and I will be running an underground line from my house’s main panel. For the shop itself, I picked up a 100 amp box and 12/2 wire when I bought the light fixtures. I am planning on placing outlets spaced every 48” at around 48” high. As I don’t have any of my equipment wired for 220 yet, I thought the 12/2 would work fine. I am planning on putting my tablesaw, dust collector, and compressor on their own circuit. Should my planer have its’ own circuit also? Normally how many outlets do you group onto one circuit? Every third or fourth one?

I had initially thought about running whatever 220 lines I might eventually need but my reservation for doing this is that I know I’m going to end up moving equipment around until I have a better feel for my machine layout so I am a bit hesitant to wire in the 220 only to have to put in more later or rerun some of the lines. As it stands right now, I have the capability to convert my tablesaw, lathe, and dust collector to 220 and am planning on adding a bandsaw in the next year or two. So things will definitely change positions as time goes on.

I’m thinking that I’ll just leave all my machines set up on 120 until I am more firm on where I want everything. Since I live in Georgia with a mild winter, I am planning on waiting a little while on the insulation and sheetrock so updating the 220 wiring in a few months will not be an issue. Also, waiting on that let’s me pay off some of my other shop building expenses!

Just wondering what others have done in this situation or what they think of my idea. Thanks again.


-- S. Box --- "But a Constitution of Government once changed from Freedom, can never be restored. Liberty, once lost, is lost forever." - John Adams

5 replies so far

View Damian Penney's profile

Damian Penney

1141 posts in 3989 days

#1 posted 02-20-2008 10:56 PM

For a home shop separating the circuits isn’t that important because you usually aren’t using more than one machine at a time.

-- I am always doing that which I can not do, in order that I may learn how to do it. - Pablo Picasso

View Scott Bryan's profile

Scott Bryan

27250 posts in 3820 days

#2 posted 02-21-2008 01:03 AM

220 will use fewer amps so that you can put more equipment on the same circuit as opposed to leaving them wired for 120.

I can’t imagine a situation whereby you would be using more than 1 tool at at time with the exception of dust collection/ air cleaner. This would be the only situation whereby I see you would have more than one tool on at the same time. I am assuming that your heating/air, if installed, are on a separate circuit.

-- Challenges are what make life interesting; overcoming them is what makes life meaningful- Joshua Marine

View Patrick Jaromin's profile

Patrick Jaromin

405 posts in 3830 days

#3 posted 02-21-2008 01:22 AM

In both my old garage shop as well as my new addition I had (2) 20Amp circuits—one on each “hot” of the breaker box —and installed quad boxes with 2 outlets on circuit “A” and 2 on circuit “B”. Lighting was run on an independent 15A circuit—so I don’t end up in the dark during a overload.

My dust collector requires a 20A 240V circuit, and I put in an additional (2) 240v circuits – 1@15A 1@20A for my bandsaw, heater and if I rewire it, the tablesaw.

This so far has been more than adequate for my one-man shop.

As for the wire, 12/2 should work fine for 240V…you don’t use a common, just two “hot” which I would assume means with Romex you’d need to mark the white white as a hot (but I’m not a licensed electrician, so take that for what it’s worth).

In my neck of the woods code requires us to use conduit—which is very convenient for rewiring and I wouldn’t do it any other way even if it weren’t required. Much easier than opening a wall.

-- Patrick, Chicago, IL

View 8iowa's profile


1580 posts in 3759 days

#4 posted 02-21-2008 02:24 AM

Stacey: I have built a similar sized shop in the U.P. I have also placed my receptacles 48” high and spaced as close as possible to every 4 to 5 feet. they are wired with #12 wire and are on two 20 amp circuits for each wall. In the back of the shop, inside a small enclosure under the stairs, I have put, on it’s own circuit, a separate 20 amp 120V receptical just in case I imight want to put a dust collector or compressor in there.

For my lighting, the six incandescent bulbs on the ceiling are on one switch and one 15 amp circuit. The three rows of fluorescent bulbs are on another 15 amp circuit, however, each row has a separate switch. Unless all the power goes off, there is no way I can be left in the dark. Each row of fluorescent fixtures are plugged into ceiling recptacles, so I will also be able to plug in a ceiling mounted air cleaner. I also have outside lights on front and rear under the roof overhang. It was required by code that I have an outside receptacle, and I’m glad to have it just to the side of the front door.

Rather than have a rather immoble table saw occuping “center stage” I have two Shopsmith 520’s. One of them is wired for 240V, so I have two 20 amp 240V recptacles, 48” high half way down each wall. At the present time all the rest of my tools are on 120V.

I don’t know what kind of dust collector you have, but since you are now in construction mode, give consideration to placing it outside in it’s own enclosure. Dust collector manufacturers have yet to become interested in noise levels, so having it on the other side of an insulated wall will make for a much more pleasant shop atmosphere. I have a smaller dust collector that is very mobile and connects to the tools with 2 1/2” flex hoses. Since it is relatively quiet I have yet to decide whether to use it as is, or put it under the stairs and build a piping system.

Highland Woodworking in Atlanta is not too far from you. They have a “getting smaller” supply of 5100 BTU ceramic type electric heaters on sale for $29.95 each. I have bought three, two for up North and one for here in Gainesville. This heater is doing a great job of taking the morning chill out of my garage.

Rather than use drywall, I used OSB. It was tedious to fill in the seams with wood filler and then sand, and the texture is definitely hard to paint – three coats! However, now that it is done, it is very durable and strong enough to hold screws for wall cabinets and shelves.

-- "Heaven is North of the Bridge"

View DaveH's profile


400 posts in 3776 days

#5 posted 02-21-2008 03:03 AM

Check out my shop pics. Shows the 220/20, 220/30, and 110/20 circuits around my shop at 48” off the floor. I just finished the structure last fall and I’m still in the process of setting it up. I also ran 1/2 inch copper around the shop for air. I’d space about 4 feet apart. Try to figure out what your load will be at each plug to determine how to wire the plugs. You should not be exceeding 80% of the rated breaker capacity for a continuous load.

-- DaveH - Boise, Idaho - “How hard can it be? It's only wood!”

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