Installing a 220-volt outlet in my garage
October 4, 2010 6:42 AM Subscribe
I'd like to know how hard it would be to put a 220-volt outlet in my garage so I can do a little welding.
It's a detached garage that's surrounded by moat of concrete and asphalt, so getting new wiring out there might be difficult. The garage has an electrical panel with breakers. It's fed by individual 10-gauge wires going through plastic conduit to a 30-amp breaker in my basement. There are two red conductors, one white and one green.
It's a detached garage that's surrounded by moat of concrete and asphalt, so getting new wiring out there might be difficult. The garage has an electrical panel with breakers. It's fed by individual 10-gauge wires going through plastic conduit to a 30-amp breaker in my basement. There are two red conductors, one white and one green.
Even if you have enough juice coming into the sub-panel in the garage, you're gonna need an electrician to wire up the outlet.
Get a welder. See what plug it requires (merely saying "220" doesn't cut it - how many amps?) The current 30 amps is unlikely to be enough.
What is likely going to happen is a new, larger breaker will be put in the main panel, new wires (if they fit) pulled through the conduit, new sub-panel in the garage with the existing breakers PLUS a new breaker for the welder outlet.
posted by notsnot at 7:01 AM on October 4, 2010
Get a welder. See what plug it requires (merely saying "220" doesn't cut it - how many amps?) The current 30 amps is unlikely to be enough.
What is likely going to happen is a new, larger breaker will be put in the main panel, new wires (if they fit) pulled through the conduit, new sub-panel in the garage with the existing breakers PLUS a new breaker for the welder outlet.
posted by notsnot at 7:01 AM on October 4, 2010
This might be an option for you.
You'll need two separate circuits to plug it in to but it might be a cheap and easy way to go about getting 220v.
I'm not sure I agree that you have no business doing it yourself. Wiring is pretty straight-forward as long as you can follow basic directions and as long as you turn off the breaker / sub-panel and double check with a meter to make sure it really is off. Read that last part again and if you don't fully understand it then, yes, you have no business doing this. There are a lot of good books at Home Depot with pretty pictures that will tell you give you clear directions for doing this.
That said, if you do it wrong you could kill yourself or burn your house down.
posted by bondcliff at 7:09 AM on October 4, 2010 [2 favorites]
You'll need two separate circuits to plug it in to but it might be a cheap and easy way to go about getting 220v.
I'm not sure I agree that you have no business doing it yourself. Wiring is pretty straight-forward as long as you can follow basic directions and as long as you turn off the breaker / sub-panel and double check with a meter to make sure it really is off. Read that last part again and if you don't fully understand it then, yes, you have no business doing this. There are a lot of good books at Home Depot with pretty pictures that will tell you give you clear directions for doing this.
That said, if you do it wrong you could kill yourself or burn your house down.
posted by bondcliff at 7:09 AM on October 4, 2010 [2 favorites]
I assume then that you are not in the UK or Australia or Europe where 220V is standard?
posted by mary8nne at 7:20 AM on October 4, 2010
posted by mary8nne at 7:20 AM on October 4, 2010
Response by poster: I'm sorry, but telling me to hire an electrician is not helpful. What I'd like to find out is whether I already have 220v in the garage that I can use, or if I'm going to have to upgrade the wiring going to the garage, which is obviously going to be a much bigger and more expensive job.
posted by 14580 at 7:26 AM on October 4, 2010
posted by 14580 at 7:26 AM on October 4, 2010
Do you know what sort of welder you will use? There are nice newer models that will run off 120 volts (e.g., Miller Diversion 180). Any cost difference might be justified if you have to an extensive rewire.
posted by exogenous at 7:45 AM on October 4, 2010
posted by exogenous at 7:45 AM on October 4, 2010
220V/30A is plenty to run a wide variety of welders. Is the breaker in your house panel twice as wide most of the other breakers or is it actually two breakers tied together? If yes to either then yes you have 240V out to your garage.
Assuming you might like to run the lights at the same time as you are welding I'd install no bigger than a 20A breaker to run a welder. This means what ever welder you get needs to draw less than 20A. If the garage electrical panel has two (and this is very important) side by side breaker spaces free then you just need to run wire to a an outlet and hook them to a breaker installed in the free space. The exact details of what wire and how is going to depend on whether you welder requires just 220 or if in has a 110V leg as well. if you don't have two side by side spaces then you'll have to reconfigure until you can free up those spaces.
PS: if you can't tell by looking a meter will let you determine if you have 220V in your garage. Really though this is pretty basic stuff. An hour or two with a decent book (either bought or at the library) would go a long way.
posted by Mitheral at 8:01 AM on October 4, 2010
Assuming you might like to run the lights at the same time as you are welding I'd install no bigger than a 20A breaker to run a welder. This means what ever welder you get needs to draw less than 20A. If the garage electrical panel has two (and this is very important) side by side breaker spaces free then you just need to run wire to a an outlet and hook them to a breaker installed in the free space. The exact details of what wire and how is going to depend on whether you welder requires just 220 or if in has a 110V leg as well. if you don't have two side by side spaces then you'll have to reconfigure until you can free up those spaces.
PS: if you can't tell by looking a meter will let you determine if you have 220V in your garage. Really though this is pretty basic stuff. An hour or two with a decent book (either bought or at the library) would go a long way.
posted by Mitheral at 8:01 AM on October 4, 2010
Bondcliff's gizmo would be fine on a temporary basis if you've got two 110V circuits going to the garage that aren't being used for anything else....but I really wouldn't risk it, especially for something you plan to leave in place. (Also, that gizmo will kill you dead if the two circuits somehow happen to be on different phases -- impossible in your case, but important to note)
It's probably a good idea to have a "master" 30A breaker on the garage panel as well as the one in your house, just to be safe.
Seriously, though. You should be able to get an electrician out to give you a free or almost-free estimate.
posted by schmod at 8:06 AM on October 4, 2010
It's probably a good idea to have a "master" 30A breaker on the garage panel as well as the one in your house, just to be safe.
Seriously, though. You should be able to get an electrician out to give you a free or almost-free estimate.
posted by schmod at 8:06 AM on October 4, 2010
I'm sorry, but telling me to hire an electrician is not helpful.
Sure it is. Call one to give you an estimate, and they'll tell you whether it's possible.
posted by electroboy at 8:42 AM on October 4, 2010 [1 favorite]
Sure it is. Call one to give you an estimate, and they'll tell you whether it's possible.
posted by electroboy at 8:42 AM on October 4, 2010 [1 favorite]
Its doubtful that you would already have 220v in the garage. A meter will tell you for sure although it should be pretty obvious when you look at your main circuit breaker panel. From what I understand you'll need a sub-panel in the garage.
If you don't don't to cut up your "moat" then you'll have to put the new wiring in overhead which can be a challenge. You will have to check your local electrical codes to see what is allowed. You may not be allowed to do this project without an electrician's license. There also is the possibility that if you do this project on your own and the garage burns down with your car in it that your insurance will not cover it. So you may want to check with them as well to be on the safe side.
posted by JJ86 at 8:55 AM on October 4, 2010
If you don't don't to cut up your "moat" then you'll have to put the new wiring in overhead which can be a challenge. You will have to check your local electrical codes to see what is allowed. You may not be allowed to do this project without an electrician's license. There also is the possibility that if you do this project on your own and the garage burns down with your car in it that your insurance will not cover it. So you may want to check with them as well to be on the safe side.
posted by JJ86 at 8:55 AM on October 4, 2010
In the US you get 220V by connecting to two out-of-phase 110V lines rather than the "usual" hot-neutral pairing for a 110V line. It should be easy to tell if you have 220 in the sub-panel by looking at the breaker in the main panel. If you don't have wires leading away from both "hot" bus bars in the breaker panel, then you only have single-phase and can't get 220 there without running a new conductor.
bondcliff: "Wiring is pretty straight-forward as long as you can follow basic directions and as long as you turn off the breaker / sub-panel and double check with a meter to make sure it really is off."
I know you're trying to throw in enough caveats here, but really this is the kind of thinking that gets people into trouble. That is not all there is to it -- a short-but-incomplete list of topics would include gas-tight fittings, proper splices, testing procedures, junction box specs... people spend years of their life learning how to do this kind of wiring properly for a reason. The correct answer has really already been given here: An electrician can come and give a free estimate, and included in that estimate will be a list of what needs to get done, which either will or won't include "run new conduit/pull new 110 phase/etc" and will give you the definitive answer to your question in addition to putting you touch with someone who's actually qualified (and insured) to do it.
posted by range at 9:29 AM on October 4, 2010 [1 favorite]
bondcliff: "Wiring is pretty straight-forward as long as you can follow basic directions and as long as you turn off the breaker / sub-panel and double check with a meter to make sure it really is off."
I know you're trying to throw in enough caveats here, but really this is the kind of thinking that gets people into trouble. That is not all there is to it -- a short-but-incomplete list of topics would include gas-tight fittings, proper splices, testing procedures, junction box specs... people spend years of their life learning how to do this kind of wiring properly for a reason. The correct answer has really already been given here: An electrician can come and give a free estimate, and included in that estimate will be a list of what needs to get done, which either will or won't include "run new conduit/pull new 110 phase/etc" and will give you the definitive answer to your question in addition to putting you touch with someone who's actually qualified (and insured) to do it.
posted by range at 9:29 AM on October 4, 2010 [1 favorite]
Two things....
You have enough wire to get both 120 and 220 out there. It may/may not be there. Hard to tell from what you relate.
If you only had a single 30A, 120V circuit, you wouldn't need two red wires. What you may have is two phases of 120V, one phase on each red wire. The white would be neutral and green would be ground. With two phases of 120V being present, if they are 180 degrees out of phase (the normal), you'd get 240V.
I'd still get an electrician, unless you have a meter and are comfortable making measurements, plus, there's never any guarantee things are wired correctly to begin with. I can do just about anything DIY, but I normally defer to licensed electricians when doing anything to a panel. It's out of consideration to the next owner, more than anything.
The critical thing is that it would not be necessary to run more wire. You'd just to make the connections properly and install your outlet.
posted by FauxScot at 9:55 AM on October 4, 2010
You have enough wire to get both 120 and 220 out there. It may/may not be there. Hard to tell from what you relate.
If you only had a single 30A, 120V circuit, you wouldn't need two red wires. What you may have is two phases of 120V, one phase on each red wire. The white would be neutral and green would be ground. With two phases of 120V being present, if they are 180 degrees out of phase (the normal), you'd get 240V.
I'd still get an electrician, unless you have a meter and are comfortable making measurements, plus, there's never any guarantee things are wired correctly to begin with. I can do just about anything DIY, but I normally defer to licensed electricians when doing anything to a panel. It's out of consideration to the next owner, more than anything.
The critical thing is that it would not be necessary to run more wire. You'd just to make the connections properly and install your outlet.
posted by FauxScot at 9:55 AM on October 4, 2010
What I'd like to find out is whether I already have 220v in the garage that I can use, or if I'm going to have to upgrade the wiring going to the garage
You should probably put these goals in your question, then. The green wire *may* mean you already have 220 out there, but you can't be sure until you check it with a meter.
It's fed by individual 10-gauge wires going through plastic conduit to a 30-amp breaker in my basement. There are two red conductors, one white and one green.
Are you saying here that you have five wires coming from (or going into?) a 30A breaker?
posted by rhizome at 9:55 AM on October 4, 2010
You should probably put these goals in your question, then. The green wire *may* mean you already have 220 out there, but you can't be sure until you check it with a meter.
It's fed by individual 10-gauge wires going through plastic conduit to a 30-amp breaker in my basement. There are two red conductors, one white and one green.
Are you saying here that you have five wires coming from (or going into?) a 30A breaker?
posted by rhizome at 9:55 AM on October 4, 2010
Response by poster: The sub-panel in the garage is fed by a 30-amp double-wide breaker in the main panel located in the basement. It might the be the 220v breaker Mitheral mentioned.
Rhizome, maybe I'm remembering the wires coming into the garage subpanel incorrectly. I'm sure there were two red wires that terminated on each side of the hot bus. There were also one black and one white conductor. I also thought there was a green conductor coming through the conduit, although that does seem odd.
As for the other questions, I've been looking at a Millermatic 211 dual-power 120/240-volt MIG welder. I already own a generator-powered welder mounted on a trailer but it's stored somewhere else and doesn't do MIG. I could also use 220/240 for a bigger air compressor and a mill.
I'm going to hire a licensed electrician to do the work. It sounds like I just going to need to have an outlet or two installed. Thank you for all your helpful advice.
posted by 14580 at 11:42 AM on October 4, 2010
Rhizome, maybe I'm remembering the wires coming into the garage subpanel incorrectly. I'm sure there were two red wires that terminated on each side of the hot bus. There were also one black and one white conductor. I also thought there was a green conductor coming through the conduit, although that does seem odd.
As for the other questions, I've been looking at a Millermatic 211 dual-power 120/240-volt MIG welder. I already own a generator-powered welder mounted on a trailer but it's stored somewhere else and doesn't do MIG. I could also use 220/240 for a bigger air compressor and a mill.
I'm going to hire a licensed electrician to do the work. It sounds like I just going to need to have an outlet or two installed. Thank you for all your helpful advice.
posted by 14580 at 11:42 AM on October 4, 2010
Measure from either red to white. You should get 120V.
Measure from red to red. If you get 240, you have two phases, thus 240. (My suspicion.)
If so, wiring an outlet TO CODE is all you need.
posted by FauxScot at 3:47 PM on October 4, 2010
Measure from red to red. If you get 240, you have two phases, thus 240. (My suspicion.)
If so, wiring an outlet TO CODE is all you need.
posted by FauxScot at 3:47 PM on October 4, 2010
range writes "In the US you get 220V by connecting to two out-of-phase 110V lines rather than the 'usual' hot-neutral pairing for a 110V line."
Actually in the US 99.999% of house power is single phase. We get 240V (two 120V hot legs and a neutral) by centre tapping the step down transformer servicing the house. Both hot legs are the same phase but have a potential difference of 240V. Two and three phase power is very different and is only used commercially/industrially where you have large motor loads.
14580 writes "I'm going to hire a licensed electrician to do the work. It sounds like I just going to need to have an outlet or two installed. Thank you for all your helpful advice."
If you don't need the outlet far from your sub panel this is like a 1-2 hour job. If you do want the outlet far from your sub panel then you can save a lot of money by stringing the wire yourself and just getting your electrician to terminate it at each end.
posted by Mitheral at 6:15 PM on October 4, 2010
Actually in the US 99.999% of house power is single phase. We get 240V (two 120V hot legs and a neutral) by centre tapping the step down transformer servicing the house. Both hot legs are the same phase but have a potential difference of 240V. Two and three phase power is very different and is only used commercially/industrially where you have large motor loads.
14580 writes "I'm going to hire a licensed electrician to do the work. It sounds like I just going to need to have an outlet or two installed. Thank you for all your helpful advice."
If you don't need the outlet far from your sub panel this is like a 1-2 hour job. If you do want the outlet far from your sub panel then you can save a lot of money by stringing the wire yourself and just getting your electrician to terminate it at each end.
posted by Mitheral at 6:15 PM on October 4, 2010
This thread is closed to new comments.
Hire an electrician.
Hire an electrician.
Hire an electrician.
Have I made myself clear? If you don't know the answer to your question, or have to look it up somewhere, you have no business installing a 220V circuit.
posted by schmod at 6:55 AM on October 4, 2010 [1 favorite]