Advice on wiring 220V circuits for workshop

[sleepy hollow]

I am finishing my 1500 ft2 basement. Part of the basement will become my workshop. It will be approx. 13' x 30'. This is about the same area as a 20 x 20 garage. I want to anticipate 220V needs for future equip. I have a 100amp subpanel about 30 feet away with plenty of capacity. So I was going to run 2 dedicated 220 circuits. I have never done 200v to receptacles before, only to fixtures like appliances. So, what would you recommend in the way of wire guage and receptacles? Is there a basic standard for 220v tools like dust collectors and table saws, for example.

I was thinking that using #10 wire would be enough since that would allow me 30 amps per leg, which is a lot of juice. Also, do I need three wires plus ground, or 2, or 4? I currently have two hots a neutral and an isolated ground to my subpanle from the main which has two hots, and a combined neutral/ground setup as the service entrance.

Thanks.

[Sparks]

Do you know what equipment you will be buying in the future, if so figure the actual load of everything you will be operating at the same time. Is the equipment 220v? I'm sure you'll want 120v receptacles as well and of course you'll need lighting. I would draw up a plan of your anticipated shop and electrical needs and figure it from there.

[bkrahmer]

Sparks is right, but doesn't really answer your questions. :) If it were me, yeah, I would run 10/3 to some boxes on a 220 circuit. The Romex brand 10/3 cable is orange. I would just wire nut the connections and leave the breaker off until you have equipment to plug in. Don't buy the receptacles until you need them, so you don't buy the wrong ones. The 220 outlet I just wired for my dryer uses a dual-gang box. I think that's the standard, probably because you need the capacity to avoid wire fill violations. 60 amps at 220 (30 each phase) is almost 20 hp, so I think that should be enough, unless you like to run every machine in your shop simultaneously. :)

[sleepy hollow]

Thanks. I really do not know yet what I will be buying specifically, but over time I expect to acquire at least one or two 220v machines.

Yes, I certainly have the other wiring needs and they are pretty much nailed down for 110 receptacles and lighting. Sounds like the orange stuff will do it. I have already used that for my 2 30 amp hot water heaters.

Leaving the boxes blank sounds like the ticket.

Thanks.

[Sparks]

Well I mentioned figuring anticipated electrical needs and drawing up a tentative plan for figuring box placement and ampacities. You certainly want to consider box placement so you don't need extension cords running to machines if you decide on different locations than originally thought. Being vague sometimes allows the one asking the questions to think about these things before they start. Planning these type of jobs sometimes goes a long way in ensuring you're happy with the final result. Especially if drywall is going up. If it were me, I would figure out exactly what I was going to buy and wire accordingly. Of course I was also figure a little extra for future needs. But I guess if all you're asking is yellow or orange, then orange it is :)

[kadoka]

12 ga should be fine for any tools running on 220v. 220v items draw half the current as the same item running on 110v.

[Sparks]

Yeah that's true but being that he's not quite sure what he'll be buying yet or doing exactly, oversizing wouldn't hurt. You can still always use a 20 a breaker with #10 wire and the price isn't much difference.

[sleepy hollow]

Thanks again. I happen to have some #10 left from re-wiring the water heaters. I can do at least one circuit that way. I'll add another 220v, as well just to be sure about placement. Might use 12 on that. But we'll see.

But, how many wires should I run -2 or 3? Seems like 2 plus ground is enough, yes? I guess I am not sure enough of when 3 wires is needed vs. 2. Is the third wire generally for 110v controls neutral?

[bkrahmer]

oversizing wouldn't hurt At the prices of copper these days, it sure can hurt the pocketbook! I agree that oversized is better than undersized, but as I pointed out, 12 ga on 220 can do 20hp! That is a ton of electricity!!!

But, how many wires should I run -2 or 3? I thought 220v always used three conductors, except for oddballs like central air conditioners. I've only done rough-in, so I might find out when I hook everything up that I wasted a conductor here and there. :)

[sleepy hollow]

My well pump is 220v 20amps and has a 12/2 wire running to it that I have to replace since there is a junction box I need to eliminate. Maybe I'll take another look...

[Sparks]

This is sort of why I mentioned drawing out a plan and having an idea of what you plan on buying, cause we could go on forever about this if we don't know exactly what it is you'll be running. :? There are 220v loads that run on 2 hots and one ground. That's it, no neutral. Then there are other 220v loads that require 2 hots, one neutral and one ground. Regarding wasting copper, if you really want to get technical, we could argue about decreased electrical consumption due to a reduction in voltage drop and cooler running conductors. Savings would be small and would depend on usage but this has been proven. Good luck with the project. :)

[bkrahmer]

I stand corrected on the number of conductors. Sparks is right, some things use the neutral, some don't. I was confused because I knew dryers take 3 conductors. When I referenced my electrical book, I found that a dryer actually has 220 subsystems and 110 subsystems. Strange.

[kpi]

Hello Sleepy Hollow, You might want to consider running conduits and boxes only at this time for future shop tools. You can pull the propper wires later when you know exactly what you need. Just to be clear, Wires are sized to the aperage draw of the tool and not (generallyspeaking) the voltage.
Best regards, Kirk

[sleepy hollow]

Thanks again, all. I certainly understand the value of a plan. In this case I am actually trying to plan for flexibility. Obviously I cannot have infinite flexibility. But so far, I have quite a bit. I have installed a 2" PVC pipe from my subpanel to the workshop ceiling with a nylon pull cord inside to allow me to pull additional circuits later. Second, I am reasonably sure that I will never need more than 2-220v receptacles. I have looked at the equipment I might add to my existing shop and only find that a high end tablesaw and high end dust collection system are likely to need 220V.

Based on the info you all have provided, I probably would cover 95% of any eventuality by running 10/3 cable to 2 separate boxes. Probably overkill, and, yes, might be 40 ft of one or two wasted #10 copper wires, but I will reciprocate by recycling the 40 feet of 3/4" copper tubing I removed from my water supply system as part of reworking my plumbing. unless someone else has a suggested use for the tubing.

Considering the entire basement finishing project (1500 ft2) will likely cost me about 15K by the time I am done (compared to 75K+ for a contractor to do it), a bit of extra wire is not even on the radar scope.

Thanks again.

[richlife]

Hey, Sleepy Hollow. I'm really late in contributing to your question, but I've been updating my shop and equipment, so I have some ideas about your real potential needs as opposed to just guessing how much circuit to plan for. I'm assuming you will normally be the only operator.

Since you are in your house, do yourself and your family a big favor and install a dust collection system. With the size room you're talking about, you should probably plan on at at least a minimum of 1 1/2 hp system which should be able to be wired at 110 or 220 (a 2 hp or more system will certainly require 220). My 1 1/2 hp Woodtek drains 18 amps at 110v and 9 at 220v, so plan on a separate 220v line for this machine. You could run lighting from it also, but you won't want to add another 220v machine (like a jointer) that you will always want to have running at the same time as the collector. My air cleaner is just a small motor and draws very little current.

The other "full-time" machine you might add is an air compressor, but that should be no problem on the second circuit with another 220v tool running there also.

That said, then your plan for at least two 220v circuits is really a minimum depending on your other needs. In my situation, I don't expect to have more that 2 or 3 other 220v capable machines and the others won't be run together with anything except the dust collection, so two circuits is what I'm installing (most of these machines only draw 5-10 amps at 220 anyway, so one circuit with two machines still leaves me with much less than 80% load).

After that, 110v circuits handle virtually anything else. After adding a 220V jointer, I still only have 3 machines total that are 220v capable and my total power requirement for them is only 20A. The only caveat to this would be if you are running heavy duty equipment not usually found in a home shop. What you probably need to do is get a good catalog like Woodworkers Supply and dream with the biggest and best and find out what your dreams will cost you in volt/amps. (That new table saw will certainly join the group, but still won't be run at the same time.) Have fun!

[sleepy hollow]

Thanks for the discussion, Richlife. I decided to go with 10-3 cable and run only a single circuit to two boxes. That should allow me to easily handle any load I might conjure up in the future, even on a single circuit. I do plan to acquire or fabricate a dust collection system. No question I would prefer a 2hp cyclone installation. I have a small Porter Cable air compressor that runs my framing nailer and other smaller stuff. It does fine on 110v 15 amps. But, you are correct that at some point a larger compressor may be in the cards.

My shop also has dual 20 amp 110v circuits running along each long wall with alternating high-low box locations about every 4-6 feet, so I have a total of 40 amps at 110v and 60 amps at 220v available now, if I've figured that properly.

I think that will do it for the foreseeable future. However, should I need anything further, I installed a 2" PVC pipe from the subpanel to the unfinished utility room adjacent to the workshop. The pipe has a nylon cord in it to fish a wire through when needed. I can always get another circuit to the shop if I somehow outgrow this capacity.

Just finishing up the drywall as I write this. I am very excited about the whole basement project turning that corner from rough to finished. In the past year or so, I have made hundreds, if not thousands, of individual design decisions which are now being finalized and set in place with the covering of the walls. It is very satisfying so far the see that I have not encountered any significant uh-oh's to date. That could change tomorrow, but so far so good.

Thanks again for the thoughts.

[giddonah]

You'll want to take yourself out to dinner some day when you use that pvc. Nice move.

[richlife]

Thanks for giving us an update -- sometimes watching and contributing to these forums you get to know a little about people but you don't get the outcomes. Way to go on the ready-to-use conduit, also. That's something I often don't think to do, but when you do remember, the payoff is huge!

Go for the dust collector as soon as you can -- I've been amazed at how much cleaner my shop stays (if you can call plane shavings and the missed sawdust on the floor clean) and my lungs have stopped gasping. This last is most important -- hopefully there won't be a repeat of that dust induced asthma attack of last Dec.

And last week I got two wakeups on how effective the air cleaner is even though I don't see it day-to-day. Using a fine file on a small part, I noticed in a sunbeam that really tiny dust particles started down toward the floor but got caught in the faint air current and sucked up toward the air cleaner! I went over the to cleaner and took a good look at the coarse external filter -- it was covered in fine dust! And this is the stuff trapped before it gets to the 1 micron filter bag... I got this cleaner as a kit from Penn St Industies for only $115 -- great investment. I supplied the 1/2 inch plywood and labor, they provided the mechanics. I checked and it wasn't worth the effort to save 2 bucks by buying the parts -- to say nothing of the various shipping costs.

Good luck and enjoy that shop!

[sleepy hollow]

Thanks. I really look forward to getting a DC system. I should elaborate on my venting system. I needed to vent my full bath and hate the sound of the standard fan that is found in most bathrooms. Most of them are noisy with little effectiveness. I also needed to take the air 30 feet to the other side of the basement before exiting through a preexisting vent no longer being used by a previous kitchen island cook top. So, I ended up buying a Panasonic in-line fan. It handles 250 CFM (if I recall correctly). Well, I installed it in the ceiling of my workshop (it just fit in the joist space) with an access panel for servicing, and ran a 6" flexduct to the bathroom. The fan is almost silent. When turned on in the bathroom, you cannot hear a thing, yet it has quite a nice draw through the ceiling vent. I deliberately oversized the fan for the bathrrom, so I could tee in a second vent to my workshop.

So, now I have an ability to exhaust from the workshop to outside as well. I installed mechanical timer switches in both rooms that are in parallel, so either one, or both, operate the fan. But, it will not be left on inadvertantly since the timer(s) will shut it down eventually.

So, if I am using solvents, paints, or other aromatic chemicals or need a bit more circulation in the shop, I have the fan to help as well. Otherwise, I just keep the vent closed and the bath has the full capacity to itself.

[richlife]

More good planning! Sure beats the normal 4 inch bathroom vent.