90% odds say you don't have 3 phase electric available in your neighborhood.
If you do, you definitely don't want the installation cost, and will NEVER have enough draw to justify it's existence.
90% odds say you don't have 3 phase electric available in your neighborhood.
If you do, you definitely don't want the installation cost, and will NEVER have enough draw to justify it's existence.
50A is sufficient.
Unless there is the possibility you will have AC in the shop, or 3 or more people using equipment at the same time. Then go 100A.
I have 200 amp in the house that feeds 100 amps to the garage that feeds 30 amps to the kids clubhouse. The garage has a full wood shop as well as a well stocked garage with compressor, welder, etc. The kids clubhouse has lights and electric heat for the winter time sleepovers. The difference in cost isn't enough to justify not going overkill.
So, our plan for the house is 200A service. The garage in question is attached. Ireplied to the contractor with 70A.
A welder and a compressor are likely going to be the big hitters here. No AC in this garage unfortunately. Eventually we will be building a detached 2 or 3 car workshop that will also have an apartment above for in-laws and whatnot. The plan is to have that on its own supply, and I might go 200A total for that building so that between the 1 bedroom, small kitchenette, small electric water heater and various electronics in the apartment, and the (hopefully) 2 post lift, in addition to the welder and compressor that will move out there into the garage, there will be no shortage of juice.
You guys are masters of overkill. Not that it is a bad thing... but you can do quite a bit with a lot less than a 100amp sub.
I have a 200 amp service on my house. I have a 30 amp panel to the garage that came with the place. Lighting, fridge and garage opener comes from the main house panel separately (shared wall with house was wired with 2 circuits). With that 30 amp panel, I somehow manage to run a lathe, a MIG, TIG, drill press, bandsaw, plasma cutter, various hand tools, battery charger, etc. The trick is... there is only one guy in my garage. He can't use them all at the same time and he understands which ones "fit" together. You can even run two of almost any combo of them depending on the thickness you need to weld.
EastCoastMojo wrote: 110, 111, whatever it takes.
haha thats exactly what was going thru my mind when I was posting this 
4cylndrfury wrote:EastCoastMojo wrote: 110, 111, whatever it takes.haha thats exactly what was going thru my mind when I was posting this
Can I get you a beer Ron?
It's 7:30 in the morning!
Scotch then?
Overkill, overkill, overkill...
There is no way anyone on this board would use 200A in his home shop.
HAVING lots of tools does not mean you need a large service.
Only USING them all at the same time does.
I have a full woodworking and welding shop running mostly on 1 single 30A circuit. I have never blown a breaker.
That's because it is primarily a 1 man shop. It's really hard to run more than 2 large motors at a time. 
We have 100A service. The key to remember is that you presumably aren't using your big-ass equipment at the same time, so it ends up not being a problem. I've used a Miller 250 TIG for nearly 10 years and never popped the breaker once. Now, if the wife had everything on in the kitchen at the same time, maybe, but same thing there, the stuff is never on simultaneously.
Go big. Not just for tools, but for an electric car in the future. Even if you swear you'll never own one, the house's next owner will.
SVreX wrote: That's because it is primarily a 1 man shop. It's really hard to run more than 2 large motors at a time.
That is key. So if you're doing a project and it's crunch-time and you have some friends over to help, you'd have to play power-management? It sounds great in practice, but I'd get fired if I designed a power feed to a shop that way. The NEC does allow a certain amount of diversity when sizing panels for equipment, but it's not like 25%.
Believe me, I'm in the middle of a project right now where the service (3000A @ 480V in this case) is nearly maxed and the client want to add more equipment. It's becoming a real cluster-berk.
Go 100A. Aluminum wire is cheap. A 100A panel is barely more expensive than a 60A panel. If you actually want the panel sized properly, list everything you plan to install in the shop/garage and give that list to your electrician. He'll then size the panel correctly.
Nobody has asked the run distances.
"Cheap wire" is not so cheap if it is run long distances.
If you put a 100A subpanel in an attached garage, there is the possibility that you will then also have to up-size the service entrance. Plus, the building inspector is going to have concerns about whether you are running a business.
Ian, if you over-designed a feed for a particular use, you would also have issues with your employer.
The problem with the "go bigger" thinking is that is if you start the project with that mentality, I guarantee you will have a ripple effect through the entire project and your costs will get out of control.
The contractor doesn't care. He will be happy to charge you more for every single change order.
I agree 100A is nicer. But if the service entrance is only 200A, and the AC is large, it will raise red flags.
Everybody is simply leaving too many of the details out of the equation.
For reference, I needed a 60amp panel for my hot tub. What you are planning will pull more than that, so go big. Who knows, you might plug in your LaFerrari or 918 in there someday!
That's a heck of a hot tub.
Most hot tubs pull about 8 amps for the pump, and 25 amps or less for the heater.
4cylndrfury wrote: So, our plan for the house is 200A service. The garage in question is attached. No AC in this garage unfortunately.
Depending on how the house is laid out and what HVAC you use, it might only cost a couple hundred bucks to get some heat/A/C ducted in. My last house had an attached garage and forced hot air/AC. Adding a vent duct into the garage using the existing system was something like $300 without shopping around. Probably not enough to cool you in the summer but the heat in the winter might help keep the chill off. I moved before I could try it out. Just a thought.
Forced air heating or a/c in the house must be kept separated from a garage, both for fire separation and to keep carbon monoxide from getting into the house.
In reply to SVreX:
There's also a difference between commercial and residential. I'll admit I tend to apply commercial sizing standards to residential applications. My ex-g/f being an HVAC (commercial/pharma) engineer, is the same way so when we designed the MEP systems for her house renovation, we went a bit overboard. I installed a 60A subpanel for the new bedroom, bathroom, laundry room (gas dryer) and A/C evaporator unit. Main service is 150A with an existing 60A panel in her detached garage. I installed all of the MEP systems and it passed inspections.
We only get our hand slapped for over-sizing if we're building it (and paying for it), but otherwise it's rare. I work in the Pharma industry. We design with A LOT of redundancy. We also assume we'll be coming back to the same facility 10 years later and adding crap. Undersizing bites us.
For my own planned detached shop, I'll probably install a 100A panel, but my house has a 200A service for a 600 sq ft house, which I'll admit is grossly oversized and I barely use a fraction of that capacity.
Like others have said. Run a small sub to power the garage. Make it 100A. They are still cheap at this size. just remember, if you finish the garage, try to make it on the wall outside so you can run conduit to what you put in.
If you have a Compressor 30A and a Plasma Cutter 50A you can run out of room quick.
You'll need to log in to post.
