Wiring 220 volt outlet

Old 01-04-03, 01:45 PM
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Wiring 220 volt outlet

I'm fairly confident about this question, or at least I was until sombody told me differently today. When you are wiring a 220 volt outlet for misc. shop tools (Air Compressor, Air Conditioner, Saw, and Lathe), do I need to use 12/2 or 12/3 wire and why? Thank you in advance.
J. E. Johns
Old 01-04-03, 02:11 PM
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it depends on what type of load it will be hooked to, if it is going to a welder that
does not use 120volts, then you don't need the white wire, but if you are running it for a
any thing that uses 120volts then you need the white wire 12/3. The reason being in a
120v circuit you need the white wire to take the unused amperage back to the panel, and
not rely on the bare ground to do this. this is all for a safety thing. I could go into detail after detail, but hope this explaines it enough for you.
Old 01-04-03, 02:32 PM
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Every place Art used the word "white", I would have used the word "neutral". They're not always the same thing. In almost all cases, you use a white wire -- it's just not always a neutral.

Pure 240-volt tools can use x/2. Without knowing more, it's not possible to say whether or not x=12. The white of the x/2 is used as a hot wire and needs to be reidentified as such with a black marker on each end.

For a particular tool or appliance, you should be able to tell from the instructions whether it needs a neutral (and thus needs x/3), or whether it does not (and thus needs x/2). Most likely, everything you mentioned does not need a neutral.

For your safety, make darn sure you get the value of "x" correct.
Old 01-04-03, 02:33 PM
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Allow me to clarify that I am using 240 volt circuits.
Old 01-04-03, 02:37 PM
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Thanks Art and John. At first I thought that Art missunderstood me until John clarified his answer. I understand now and can finish the job and be ready for the inspector Monday morning. Thanks again guys.
J. E. Johns

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