# 230 volt outlet in workshop



## Daniel Holzman (Mar 10, 2009)

We will let the pros handle the details of install. You should note that you only attach the red and black wires to the breaker, since those are the hots. The white wire goes to the neutral on the panel, which you may not need if this is a 240 volt air conditioner outlet. The green is the ground, which attaches to the equipment grounding bar in your subpanel.

You said this was a workshop (separate building I assume), so the equipment grounding bar in the subpanel should NOT be bonded to the neutral bar on your subpanel. If you do not understand what this means, or are not sure how to check, you should get help from someone who does know how to verify and correct if the panel is incorrectly wired.

As for the size of the breaker, that depends on the AC draw. If you are putting in a 30A AC unit, then you need a 30A 240V breaker. I believe #8 wire is rated maximum to 40A (check NEC, I don't have it with me where I am at this moment). This would mean that the wire can handle up to 40A, which would allow you a maximum 40A breaker, but you could put a smaller breaker in.


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## Speedy Petey (Feb 1, 2004)

A 240v receptacle can be 15, 20, 30, 40, 50, etc, amps.
As stated, #8cu cable can be used on a 40A circuit. If this is just for an A/C I would not bother using it. It will be a PAIN to work with if you only need a 15, 20 or 30 amp circuit. 

I would just find the A/C you want to use and get the correct wire for it. If you find an 18k BTU for example, it is most likely all you will need is a 15A 240V circuit. Save the large wire for something that will actually need it.

What kind of breaker? One that is correct for your panel brand and type, and one that is sized properly for the circuit.


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## a7ecorsair (Jun 1, 2010)

Do you already have the A/C unit? If so, what does the rating tag say?
If you don't have the A/C you will need to figure out what size to get based on the room size and insulation installed - then you can size up the power requirements.
I take it you already have a sub panel in the shop with 240 volts available if needed. What size is the feed wire and breaker for this sub?
Or, is this shop attached to a house where you will be pulling a new circuit from an existing panel?


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## jimmike (Jun 26, 2010)

*a/c*

I want to get a unit that also has heat capability, so I think I need more amps (bigger wire) than I would for just a/c. Plus the wire is free!


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## a7ecorsair (Jun 1, 2010)

So you are looking at putting in a heat pump?


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## jimmike (Jun 26, 2010)

*a/c*

something like this:

http://www.lowes.com/pd_89279-2251-FAH12ER2T_4294859075_4294937087?productId=3046952&Ns=p_product_quantity_sold|0&pl=1&currentURL=/pl_Air%2BConditioners_4294859075_4294937087_?newSearch=true$ddkey=http:SearchCatalogDisplay$Ns=p_product_quantity_sold|0


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## Speedy Petey (Feb 1, 2004)

Nice how they give the voltage, but not the amperage. :whistling2: 

A 12k btu cooling unit @ 240v will be around a 6-7 amp draw. That unit will likely require a 15 or 20A circuit.

I understand that the cable is free, but how much do you really need? #14 or #12 cable is NOT that expensive, and is MUCH easier to work with.


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## jimmike (Jun 26, 2010)

I guess I should start from the beginning. Bear with me, I am obviously no electrician. When I built and wired my shop initially, I also had this same wire (8/4) and wired it from (what I now know as) a double-pole, 40 amp breaker in my house panel box to a sub-panel box in my shop where I put in 2 - 20 amp circuits and 1 - 15 amp circuit. I did not know that this double pole breaker was FOR 220. However, everything works as it should as it stands now. I work construction part time and I spoke to the electrical crew and was advised that I would need a bigger wire to add an air conditioner/heater to the shop. Now that background is out here, what do you suggest I do in order to add an air conditioner/heater?


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## a7ecorsair (Jun 1, 2010)

Ah, so you have a 240V sub in the shop. You should think about just adding a 20 amp 240 volt circuit. I doubt that it takes more than that. A 20 amp receptacle will let you plug in either a 15 amp plug or a 20 amp plug and at 12000 BTU I wouldn't think it would be any more. Do you have room for the breaker?


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## Speedy Petey (Feb 1, 2004)

jimmike said:


> ...., I also had this same wire (8/4) and wired it from (what I now know as) a double-pole, 40 amp breaker in my house panel box to a sub-panel box in my shop where I put in 2 - 20 amp circuits and 1 - 15 amp circuit. I did not know that this double pole breaker was FOR 220.


A double pole breaker is not for "220". 
What you have is a 120/240v feeder to your sub-panel. This is perfectly normal.


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