[jim72911t]

Hi,
I need more power in the garage! I've got a detached garage, 20x25", that needs 220V. I've bought a 100A sub panel, and am getting ready to trench for the wiring. The total wire distance between the main panel and sub panel is +/-100ft. Electricity demands are as follows: light circuit, 20A; 110V electrical outlet circuit, 20A; 220V, 20A circuit for 5HP compressor motor; 220V outlet for welder, 30A; 220V circuit for mill/lathe, 30A.

Okay, I don't have the welder, mill, or lathe yet, but want to be ready with the electrical when they come. I also realize that the total amperage for all circuits exceeds 100A, but the mill, lathe, and welder will likely never be run at the same time. The compressor will be hard wired to a switch, so, if I'm working in the garage, it could come on at any time. There is also the possibility that I will need a 220V circuit for a combo heat pump/ A/C unit I have laying around.

Question: what gage wire should I run from the main panel? My boss (who's wired all of the 3 phase stuff in our machine shop), says I'll be fine with 8ga. I was thinking 6ga. The guy at Lowes just told me that, to be on the safe side, I should run 4ga. The wire will be buried in conduit, but, remember, it is about a 100ft run.

Any thoughts? I'd like to trench this weekend.

Thanks,
Jim