220 Volt shop outlets

[Steve Roxberg]

None of my current 220 tools in the shop use/need a 30 amp circuit. They all run on a 20 Amp individual circuit and I haven't ever had a problem. The run length is short, under 50 feet at most so that helps I'm sure.

Current 220 tools include SawStop, Planer, Jointer, and Dust Collector. None of these will be upgraded that I'm aware of since I'm happy with all of them.

I don't own a big compressor and might like one but don't have a need today.

What tools might I need up with that would/could require 30 amp.

I ask the question because I'm wiring the shop and then dry walling it. Trying to decide if I should run 10 - 3 instead of 12 - 3 to hand any future increase in need. I'd probably reuse my 20 amp breakers and outlets since they work. The only advantage would be the ability to convert any of those outlets to 30 amp if I needed.

Any thoughts on ways to future proof a wiring job? I have no clue where to put the outlet if it is a new tool, so maybe I'm over thinking this. I tend to do that.

Thanks in advance for your advice.

[Jerry Bruette]

Since you're doing the whole shop why not put your wiring in conduit, on top of your drywall? Could make it easier to add or move outlets in the future.

[Ole Anderson]

240 v-20 amp is good for 3 hp, so unless you anticipate something bigger, you are good. What tools need a 30 amp 240 v circuit? An upgrade to a 5 hp dust collector, which you say you don't need. A welder? A wide belt sander? But those might need even more than a 30 amp circuit. If you can stand dealing with 10 gauge copper, just run everything 30 amp if you anticipate staying at no more than 5 hp. If you can locate a subpanel in the shop, surface mounted, you have the ability to run any future circuits in conduit on the surface as Jerry suggested.

[Mike Henderson]

I ran 12/2 for all my 240V outlets before I put up the drywall. If I had to do it over again, I'd probably run 10/2 just because the cost wouldn't be that much more.

I only have one machine that I had to put in 10/2 (5 HP machine) after I put up the drywall, however. And that's been over maybe 6 years in the shop.

Mike

[John K Jordan]

I have a 5hp cyclone DC and a 5hp air compressor. Some people use table saws with big motors. I also use several welders and a plasma cutter that each take a 50 amp circuit. I don't know of anything else in a shop that would need wire for over 20 amps.

For all my 20 amp 220 circuits I ran 10-2/g in case I needed it later. The difference in cost of materials was not significant.

JKJ

[Ben Rivel]

As others have said unless you plan on running over a 3HP motor on anything you dont need anything more than 20 amp circuits. If you are really worried about it though, maybe wire one 30 amp circuit up and put an outlet for it on each side. That way you'll be prepared should you ever need it.

[Wade Lippman]

Grizzly 3hp Cyclones are 30a.
10/2 is not a big deal, I ran 6/3 for my subpanel and 8/3 for my generator. Better to run it while it is convenient then when you find out you needed it.

Actually Grizzly calls for 40a, but I don't think anyone does that.

[Jon Endres]

I'm currently wiring my shop. All of my 240v stuff will be wired with 12 ga stranded THHN in 3/4" EMT, surface mounted, with NEMA 6-20R receptacles and plugs. My biggest machine motor is a 3-hp Unisaw, and even that came with a 15-amp plug on the cord. Every other 240v machine is 2-hp or less, jointer, bandsaw, dust collector, air compressor, radial arm saw. My longest wire run, up the wall, across the ceiling and back down the wall will probably max out at 65 feet. I will be installing a receptacle for a welder but that will be wired with appropriate gauge copper wire. I got my wire really cheap off craigslist, but even if I had to pay full price, I probably wouldn't have changed the plan. I also was going to use twistlocks, but haven't yet found an advantage for those.

[Bill Arnold]

When I wired my shop, I wanted to do it one time. So, I ran 10-2 w/g to all 220V outlets, putting at least one on each wall whether I had a tool there at the time or not. Each wall also has its own 110V circuit run with 12-3 w/g. It might sound like overkill but, as I said, I only had to do it one time.

[Larry Frank]

When I had my shop and garage wired, I had all the wiring done for 30 amp circuits. The extra cost was not very much. I recently got a 5 hp cyclone that needed 30 amps and was easy to change a breaker and outlet.

[Steve Roxberg]

Just confirming that I will run 10/2 with a ground. Is that correct?

[Jim Becker]

Just confirming that I will run 10/2 with a ground. Is that correct?

Correct for general machinery circuits of up to 30 amps. (can also be used for 20 amp circuits as a hedge for future compatibility with 30 amp demands if the breaker and terminations are changed appropriately)

[Chris Padilla]

10/2 w/ground is fine but you might consider 10/3 w/ground (the w/ground is implied, BTW...so just 10/2 or 10/3). 10/3 will give you a red conductor to use and can be handy for switched outlets or running two circuits in a single run. For example, a duplex outlet but each outlet of the pair is on a separate circuit (a 'black' 120 V and a 'red' 120 V side by side). It might be overkill but I overengineer just about everything. Certainly 10/2 is probably good enough.

[Mike Hollingsworth]

A 250' roll of 10 is cheaper than 100 ft rolls of 10 and 12.

[Lud martinson]

Steve, I agree with the 10/2 guys installed externally from a panel on your shop wall as well. The issue is when several machines kick on simultaneously and the startup draw may exceed your protected circuit.