I want to run 125 amp service in my shop I need to know what size wire to run? I have a 220 air compressor and welder lights A 110 lift this is a home shop .

Do you need a full 125 or would 100A work? How far away is the sub panel from the main panel going to be?


#1 THHN copper for 125A, #2 for 100A. Most sub panels are rated 125a but only fed with 100A

Les than 80 feet. That seems like over kill at #2 copper? I want to put in the ground .

If it was the incoming service in you could get away with a #4 copper. Since it isn't the incoming service you can't de-rate. #2 is rated for 115 Amps @ 75deg C (I assume your sub panel lugs are only rated to 75C not 90C) You can use a direct burial alu conductor wire, but for my shop, I'd sleeve #2 copper in PVC pipe.

For reference

http://www.cityelectricsupply.com/Images2/Ampacity%20Chart.pdf