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Jason Thaxton
05-03-2005, 6:36 PM
I have a 4 curcits in my garage all for 110 they all have 12/2 wire. They run on a 20amp breaker. I went down to home depot and got a 220 volt recepticle. Now the question is how do I convert one of these curcits to 220? My breaker says 110/220.

Tom Hurlebaus
05-03-2005, 6:53 PM
Jason,

This isn't going to be much of an answer, but you shouldn't have to convert any of your existing circuits. Based on your comment about having 4 circuits in your garage, I'm assuming you have a service panel in the garage. Unless it's a pretty small service panel, there should be space for your new double slot 220 breaker.

Now your comment on a 20 amp breaker concerns me in that it could mean that you only have a 20 amp circuit run to the garage and then you have four circuits running off that ?? You need to determine what amp service you have running to the garage and what amp draw your 220 machine will need.

I added a 220 circuit to my garage panel last year and it was pretty simple. I also think you'll need more that 12/2 for 220 ... I can't remember what I used.

I'm sure you'll get better responses from the electrical experts on this board, but they'll probably need a little more info ... specifically what amp service feeds the garage.

Rob Russell
05-03-2005, 7:33 PM
Jason,

A couple of questions to clarify things.

You say 4 circuits. Does that mean you have 4 separate circuit breakers supplying those 4 circuits?
Are the breakers full width (1" wide) or are any of them the 1/2" narrow width breakers? A different way of asking this is if you pull a pair of the 110v breakers, will your 220v breaker connect to both busses in the panel? Another way to verify this is what kind of breaker is it - model number would help because we can look itup on the manufacturer's website.

In terms of how you would add a 220v circuit, you'd need to pull (2) of the existing breakers and install the new 220v breaker. A 220v circuit has 2 hots and a grounding conductor. In your 12/2 NM-cable, you should have a black, white and bare conductor. The black goes to one pole on the 220v breaker. Take some electrical tape and mark both ends of the white conductor (that "reidentifies" it as a hot conductor). This reidentified conductor goes to the other pole on the 220v breaker. The bare grounding conductor goes to the grounding bus with the other bare (or green) wires.

Rob

lou sansone
05-03-2005, 8:09 PM
Rob has done a great job of explaining the process. the 12 gauge wire will handle 20 amps ( that is code )

lou

Allen Bookout
05-03-2005, 9:45 PM
Number 12 wire is approved for 20 amp 220. You only need to go to Numer 10 wire if you are going to 30 amps. Your old breaker that is labled 110/220 is probably a single pole. You probably need a two pole 220 breaker, depending on the brand, as you need to come off of both power bars in your box to get 220. If you try to come off a single bar you will only be able to get 110 no matter how many wires you hook up to it. Make sure to get the same brand breaker as your box as most are not interchangable. Ask a person at your supply place. There should be someone there that has enough knowledge to pick out the correct breaker for you. To wire the breaker attach the white and black to the two poles on the breaker and attach the ground wire(bare or green) to the ground bar, just as the other ground wires are attached. Since you are going to use the white wire (neutral) for a hot wire to meet code you should color the ends of the white wire a color other than green or white (any other color). You can use paint but they make narrow colored tape just for that application. In any case turn off the power to the box while you are working on it or be extremely careful as a lot of electrons are flowing through there.

Good Luck! Allen

Jason Thaxton
05-04-2005, 12:10 AM
200 amp service 4 20amp curcits 4 outlets on each curcit. I overdid my garage wiring when i built my house my garage has 16 outlets in it:) I was mistaken on the breaker it says 120/240 not 110/220. I took the panel off and it looks like these breakers can do 220 or 110 depending on how they are wired. Does this sound right? I plan on taking a breaker to the electrical supply house and have them look at it to make sure. so once I determine if the breaker can handle 220 i need to take the nuteral wire and connect it to the breaker mark the white wires with black tape and install my new outlet? and of course take the other 110 outlets out of the curcit. does all this sound right to you electicians?

Allen Bookout
05-04-2005, 12:32 AM
That is the best way to handle it. The electrical supply guys will set you up right away. I do not know if you have a GE, circle D or what but I would bet that you will have to have a new breaker. If your situation does not require a GFI set up it will be really cheap. If it does it is going to cost some bucks. In any case your local electrical suppy people will make it easy for you.

Steve Stube
05-04-2005, 1:36 AM
Jason, there is another method, one I prefer and used throughout my shop's 220V electrical system. First, 220V circuits are often used as motor feeds and motors are subject to control circuits with coils and starters etc. which often are feed from only one leg of the 220V supply and as such there is an imbalance in load which is carried by the return line (some have called this wire a ground in the posts above). I have an problem calling a return (due to imbalance) a ground - just doesn't work for me. Being mindful that motors sometimes short out inside the housing and not being particurarlly fond of shocks I like an equipment ground to the motor or appliance I'm adding to the circuit. I can't use the third wire as an equipment ground if it is already carring the imbalance load, right. It would be setting a trap for the unspecting. For these reasons, I wired with 12-3 w/g (and some 10-3, 8-3, and 6-3 all w/g) where I use black and red as the hots, the insulated white for return and the bare conductor is available for the equipment ground.

Jeff Sudmeier
05-04-2005, 7:01 AM
Jason,

I just can not stress this enough! You can only use 20 amps using your existing wiring. The breaker for my DJ20 is a 20 amp. However, my breaker for my Bandsaw is 50!

Also, make sure that you use a different style plug for your 20 amp 220v circuits than your 20 amp 110v circuits.

Have fun!

Jack Wood
05-04-2005, 7:57 AM
:rolleyes: Jason my advice to you is that if you are asking this question then you need an electrician. If you want to try your hand at wiring at least hire one to come in and check your work out before you turn the juice on. When dealing with things that can kill you or burn your house down this is no time to mess around. I wired my work shop my self, all the way up to the breaker box, but then hired a pro to check my work out and wire the box in. He came out one day to look at the job and told me what materials to use and how things needed to be done. Then later that week he came back and did the hook up. He found a few small things I could do better and showed me how. Then he wired up the box, turned on the main breakers and checked everthing again. It was the best $250 I have ever spent. So if you want to do the labor that's cool but get that 'trician to check it out, you'll rest easier at night.

Rob Russell
05-04-2005, 5:52 PM
Jason, there is another method, one I prefer and used throughout my shop's 220V electrical system. First, 220V circuits are often used as motor feeds and motors are subject to control circuits with coils and starters etc. which often are feed from only one leg of the 220V supply and as such there is an imbalance in load which is carried by the return line (some have called this wire a ground in the posts above). I have an problem calling a return (due to imbalance) a ground - just doesn't work for me. Being mindful that motors sometimes short out inside the housing and not being particurarlly fond of shocks I like an equipment ground to the motor or appliance I'm adding to the circuit. I can't use the third wire as an equipment ground if it is already carring the imbalance load, right. It would be setting a trap for the unspecting. For these reasons, I wired with 12-3 w/g (and some 10-3, 8-3, and 6-3 all w/g) where I use black and red as the hots, the insulated white for return and the bare conductor is available for the equipment ground.

Steve,

I've got 2 topics I want to comment on - terminology and the need for a "neutral" conductor.

Terminology first. In the USA, the NEC is the most commonly used electrical code. According to the NEC, there is no such thing as a "ground" conductor. There are "groundED" and "equipment groundING" conductors (EGC). The groundED conductor is the "intentionally grounded" conductor. We laymen commonly refer to this grounded conductor as the "neutral". The "equipment groundING" conductor is what connects “the non–current-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system.” I don’t see where anyone called the EGC a “return” or implied that the EGC could be used as a neutral. Ref – 2005 NEC, Article 100 – Definitions.

In terms of the need for a neutral, most 240v machines that we would have in our residential shops don’t have contactors and/or similar control devices. If you have a machine with a contactor, I’ll bet you’ll find that it’s running with a 240v coil or there is a 240v to 24v transformer and the controls are 24v. I’d be dumbfounded if you found a manufacturer that wired their 240v, 3-wire machine such that they used the EGC as a neutral. Another problem with advocating running 4 wires to a machine that only needs 3 wires is people may not know what to do with the extra wire and which wire to choose. Do I connect the white and green/bare together and hook both to the machine? Do I hook the white to the machine and the green to the metal outlet box? Do I hook the white to the machine and cap off the green if it’s a plastic box? If you answered Yes to any of those questions – that’s incorrectly wired. A 3-wire machine takes 2 hots and an EGC. The exceptions to that rule are grandfathered dryers and stoves, where the 3-wire connection was hot/hot/neutral but those aren’t workshop machines.

If you’re wiring your 240v, 3-wire machines by connecting the white/neutral to the machines grounding wire and separately connecting the green/bare/EGC to the machine chassis, you’re bonding the groundED/neutral and groundING/EGC at the machine and that’s blatantly wrong. The NEC specificies where that bonding is to occur and that’s at the service equipment. Ref – 2005 NEC, Article 250 – Grounding and Bonding.

Jason,

Jack has a good point. If this is your first foray into wiring that's anything more than swapping out a toggle switch for a dimmer or replacing a bad receptacle, you should "get some learnin'" before you get hurt. You can buy a few good books on basic wiring at any of the home centers. If you walk into an electrical supply house that's primarily dealing with professional sparkies and knowledgeable DIY'ers, they may not want to educate you on what you need to do. If you're installing a 240v breaker, you need to understand the stuff that Steve and I are discussing - or you can get dead. That doesn't mean don't do wiring - just make sure you learn about the basics of your house's electrical system before you start swapping breakers and all.

Rob