Running 220V out to the garage?
 

My knowledge of electricity is limited.

I'm going to buy a GTAW machine that requires 220V @ 80 amps. The main breaker panel is in the house, but I have a sub-panel in the garage.

If I wanted a 220V socket out in the garage that could support the welding machine:

1) Would I have to have a new "line" run out from the main panel?
2) Could the work just be done at the sub-panel?
3) Is this something an electrician would have to see to determine?

I'm hiring an electrician to do the work no matter what, I'm just trying to get a heads up on what the required work will be.

Can you get us a pic of the sub-panel with the cover off? It may be as simple as adding the appropriate breaker to the sub-panel. More than likely you have 220v out there already.

I don't see the 3rd leg (red) for 220v

Here's what my sub-panel looks like. The big breaker in the middle is my 220v circuit.

http://rennlight.com/shop/image/2100302.JPG

You'll likely need bigger conductor than what you have anyway.

Hmm, looks like your 220V breaker is 30 amp. I need 80 amp. I'm guessing I'll have to run a "line" out to the garage.

80amps is a very big draw. First the main panel needs to have the capability to deliver that load, probably a 200amp panel. Second the sub-panel needs to be fed by large enough conductors to provide 80 amps, most likely a 100amp panel. A 4awg wire would meet the welder requirement, but considering you'll run lighting and other items I would run at least a 1awg wire. You'll need four wire to the sub-panel, red and black hots, white neutral, and a ground.
So, bascially you don;t have enough power there to run any kind of welder except maybe the smallest 120v available. Call an electrician.

John

You're going to have to run another service out to the garage if you need 80amps just for the GTAW. Just consider what other circuits you will need out there and your now your around 100 amps just satisfy the power requirements in the garage.

Let's say you have a 100 amp service in your basement fed by the meter. You cannot just add another 100 amp service off the existing box. You have to upgrade the wiring from the meter to a new box, presumably to a new 200 amp box. Then you can run an 80amp circuit from the new service box to your machine. You are responsible for the wiring upgrade from the meter to the new box, not the power company.

Hope that helps a little.

Okay, this is going to be a big freakin' deal. :D

Now I know. Thanks!

Chris, your service right now is set up as single-phase 110V. You'll need to pull a two-phase 220V service cable from your main box to this box. Hopefully, your main service can support this load. It not, you'll need to upgrade your main service box, too. You'll need a 220V breaker for your welder. You'll need a grounding block (see Thom's pic, upper right hand side). Your 110V service ties the neutral (white) wires and grounds together, but that will change with the 220V service. You'll split some of the original 110V loads onto one phase of the 220V service (e.g., black to white, plus a ground), and rest on the other phase (red to white, plus the ground). It's been quite a few years since I mucked with these things, so use my comments with a grain of salt. :)

Wow, you guys are fast typists! :D

Path of least resistance (get it?) is to add a 2nd sub-panel, leaving the existing panel as-is.

That's exactly what I was thinking.

I wouldn't have to modify the existing subpanel, and could have a second subpanel dedicated to 220V. The wall that subpanel is mounted on is interior to the garage and hollow--very easy to add a second subpanel on. I want the 220 socket on that wall anyway.

Thank you everyone.

What on earth are you welding that requires an 80 amp welder?

The GTAW (tig) machine I want (and the only one I can get in town) has a maximum draw of 80 amps. If I bother to buy a tig machine, I want it to do DC and AC (so I can weld stainless and aluminum). It's a serious machine and can weld up to 3/8" mild steel. It will be the last welding machine I ever need to buy.

Before I bought my house, the previous owner had the service upgraded from 100 to 200 amps. The electrician added a second box rather than install an entirely new one. It works real well for me. Lots of space for additional circuits if I need them in the future. The workshop has two independent 110v circuits; one GFI protected for the benches and the other on the opposite wall for the power tools (saw, router, compressor, etc). I do not have a 220 welder.

Technically, yes you can. It's not recommended of course but is legal by NEC standards.

Nonetheless, Legion, can you link some specs on the welder?

Most 80 amp TIG welders are describing their output amperage and not the input amps which are normally around 20-30 amps.

http://www.millerwelds.com/products/tig/syncrowave_200/

Both you guys have 220 sub panels except legion has no 220 breakers and Tom does.

What size is the breaker that feeds the sub panels? That determines what wire size goes into them.

Thats what we did at my house. Ran a nipple directly to the service on the outside of the house (other side of the garage wall) and ran cables to the garage box. Now have all the power that will ever be needed.

We also ran a separate 220v plug off of the box down a foot and put a washer/dryer style 220 plug there. That way you can plug in a air compressor, welder and so on without having to hard wire it to the system.

Somes serious draw there. How many amps is your main service?

"The duty cycle of the Syncrowave 200 is the highest in this class. The Precision TIG draws 81 amps when AC TIG welding at 230A/19.2V and has a limited duty cycle of 10% Duty Cycle."

I am guessing that my main service is 100 amp.

I'm going to have a friend who knows electricity better than I do look over my main an sub panels to confirm.

I wonder how much this will cost?

That's a killer welder. I seriously doubt that absent a full on fab shop you'll ever use the full AC current capacity of that thing unless you're going to weld things like aluminum dumptruck bodies, but I can't blame you for wanting to plan for it. For pretty much anything you can conceive of welding in a home shop, you'll likely never see more than a 30 amp draw. To run an 80 amp "subpanel" I'd really rather run it as a second main panel. Code would allow you to do it off of a 100 or 200 amp main as a sub, it might be easier said than done, and I'd rather do it as a second main. Won't be cheap either way.

BTW, for most stainless you'll run across, a nice mig ( think Miller 180-just bought one myself) w/ stainless wire is fine; won't do big stuff, but you likely won't run into anything ourside of industry that you couldn't do that way.

legion,

I don't know what the electrician will cost per hour in your area but the cost of wire is very expensive for 1awg or 4awg wire. I checked a couple of sites and 4awg starts at $1.50 a foot to $3.50 a foot or higher for 1awg. Copper has gotten expensive. How long is the wire run going to be? With the copper thefts so high, check a local recycler for some salvage. You can also get panels at places like Habitat for Humanity resale shops or other local building supply resale shops. In AZ we have a great place called Stardust.

Good luck

John_AZ

It's about 17 feet straight, or about 35 feet if you make the appropriate bends.

So that's about $100 for just the wiring. An electrician runs about $75 an hour around here (IIRC).

Chris,

Run bigger wire than you think you may need. With a high draw unit like a welder or compressor, you will thank yourself in the end. We had to run 2 feet with mine and still used #4 wire.

Joe

Can't you utilize aluminum for a major feed of this type?

i'm not recognizing anything in them electrical boxes, all looks different here in Europe, since we run 220 for everything

but i have to ask, 80 amps, surely you'de be running more then 1 phase right???

eg, not 2 wires for the full 220v/80A

but 3 wires, A B C, with 3 phases AB-AC-BC, each doing about 1/3rd of the work, right???
even that would be 30 A each, and serious wiring required

That's not how it works - even in Europe. Thirty amps is not exactly serious, but 80 is a bit more so.

On the topic, make sure you hire a qualified electrician who knows how to use a code book. I haven't run feeders for a welder in a long time, but you may have to size up from the ampacity actually required. For example, it may need to be sized at 125%. In this case, not the worst thing in the world. I would run a 100 amp sub (or main as suggested by others). Might even be a good time for a service upgrade to 200 amps depending on your demand elsewhere in the household, i.e. electric heaters, water heater, stove, etc. Again, because of the demand placed on your system, make very sure you hire qualified help.

BTW-your sub panel is 220 and wired for 60 amps. Unlike WB's they used 2 wire (ground wire not counted) service entrance cable on yours so the neutral is not insulated. Can't say I would do it that way as you have no ground technically. Also, the ground and neutral "shall not" be bonded at a sub panel so either way that's a code violation. As suggested, you could use aluminum SE cable. You would need to size up, but it's cheap compared to copper and much easier to install (if code for your area allows this). It would be 2/2/2 AL SE cable.

PS I'm seeing current draw at 54 Amps on the lit. Am I missing something? That being the case, you may be okay with the 60amp sub.

i can assure you that for 80 amps you would see 3 phases in Europe in any shop that uses heavy machinery, they have special plugs for em

http://www.basicfox.com/cncimg/100_0051.jpg

http://images.kapaza.com/photoslarge...00/6194402.jpg


hardly anybody would have em in a normal house, except perhaps with electrical heating, electric boilers, such as the ones i have right here (not with a plug, but wires in the wall , not just 2 wires for current, but more, seperate big breakers with 3 wires), although not with a big breaker box in the picture above, that's one for a construction yard or big machine shop

just looked it up, that kind of hardware would run (400/230 volt)
over 4 wires
above 40A has to be requested with the utility company, and they come install a new box for it
it's required here for anything that uses more then 13 kVA concurrently

I'm not arguing that. Maybe I read it wrong, but it seemed that you were suggesting that when you have 3 phase, each phase adds up to the current draw.

"but 3 wires, A B C, with 3 phases AB-AC-BC, each doing about 1/3rd of the work, right???
even that would be 30 A each, and serious wiring required"

What I'm saying is each phase is 80 amps, not 80/3.

To add to the confusion, yes, you can use alu wire. IMHO I'd run a new main w/ 4/0 alu to the new panel, then #4 to the outlet. There would be a minor voltage drop w/ #4 if you ran that to the panel,w/ would then increase the amperage blah blah.

That assumes that you'd actually ever draw 80 amps. Huge difference between 80 amps and 50 something.

Either way, if you're buying a welder that's going to be close to 3k all in, the electrical cost is going to minimal, probably around 750 or so.

ah, didn't know that, i'm no electrician, anything requiring that much juice, i'm not touching it... always thought the amps were then spread over the wires

That's not so bad.

Funny thing is, I walked into the welding supply store and told them I wanted a machine that could do Mig, and AC/DC Tig. They didn't have such a machine, but Miller used to make one and it cost around $6,000. We figured it was cheaper to buy separate Mig and Tig machines. The Mig machine I'm getting can run on standard 110 and I highly doubt I will ever draw over 30 amps with it. Any heavy-duty jobs I'd use the Tig machine for.

For reference:
Your feeders for the welder only have to be rated for the max amps but no larger than 2x max amps.

IMHO I'd have a new service from the meter brought into the garage and replace the existing sub panel with a 12+ slot panel. Size up the new service to however much your meter box can handle. It may cost a bit more but your family won't hate you for dimming and flickering lights when you're welding. Doing this now would offset the costs for any future additions you may add later.

If you want the cheap option you could run 6/3 to the welder outlet from the main panel, ($120) cord and plug the welders power, ($115 they aren't cheap) install a 60/2 breaker, ($20 SqD QO) and be done with it. Safe and code legal.

Really? I don't know if I would feel comfortable with drawing that kind of amperage out of a 100 amp box. I ran a new service from the utility because I thought my 150amp garage panel would potentially be to much for the house 200amp panel. I know the draw wouldn't be 150amps but didn't want to take a chance.

Holy smokes you guys have nice tidy panels. Mine looks like it was done after the 4th rum & coke. Cleaning up my wiring is going to be a winter project this year.

If you're not in a huge rush, keep an eye in the local classifieds, and call the local scrap & salvage yards for the cable. A friend picked up 50' of 1awg underground cable for $100.

Funny, I had thurs & fri off last week and I went to the scrap yard to unload some aluminum & copper. While I waited, some sketchy guy came up with a van load heavy copper cable. Looked like it was new. The guy at the yard asked where he got it, and he hesitated and said "uh, I bought it from my cousin." Not convincing at all, and after he pulled around to the scale the guys who worked there joked about it being stolen, but they bought it anyway. I called the cops when I got home.

Hey, what 110 mig are you getting?

I talked to my friend Tim (TimothyFarrar on this BBS) this weeekend. He told me that he would loan me his 110V Hobart indefinitely. (I suspect until he gets a house and has a place to use it himself.)

Longer term, I'll probably get a Miller 140. Anything more than that and I'll just use the Tig machine.

I want to know what the secret project is... you've alluded to roll cages. C'mon!