I need to run 220 amp service to an airconditioner will 6 gauge wire handle 40 amps?

Yes, it'll handle more than 40 amps.

I truly hope you mean that you have to run 240 Volts and not 220 amps!

Table 310.16 gives you the size and amperage for listed wires and the max amperage for each wire.

I will guess that the connections inside of the A/C equipment are listed at 75(C) and therefore we can use the center column of the "Copper" wires.

A #8 AWG wire can handle 50 Amps using listed 75(C) connections.

A #6 AWG wire can handle up to 65 Amps when used in a piece of equipment where the connections are listed at 75(C).

If you have to use the 60(C) column, then a #8 AWG will get you a max of 40 amps and a #6 AWG will get you 55 Amps.

If you truly mean that you need 220 amps then you will need wires that are 300 kcmil for 60 (C) for 240 Amp or 4/0 AWG for 230 Amp using 75(C).

Quote:

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Originally Posted by donf

A #8 AWG wire can handle 50 Amps using listed 75(C) connections.

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Don't forget, NM cable is limited to the 60 deg C column, so #8 is good for only 40A.

Hey, Stan,

Good morning! Care to join me for a metaphorical cup of coffee this fine day? I find out if I need shoulder surgery later today. Because of lung problems I'm a very high risk patient.

On the brighter side, next week I find out if the Thyroid lumps are benign. I choose not to worry about the other possibility because my shoulder hurts a bunch and I'm real cranky, even with the "Oxy" pain killer pills, which don't seem to help all that much.

Any way, here's mud in your eye!