My garage workshop currently has 60a coming via a 6/3 line from the house on a 60a breaker. The subpanel is too small (eight 1/2" slots). I am getting a large cnc router this month and am bumping the power up out there. I only have 1 220v circuit right now and have wired in 3 more (window AC unit and 2 more dedicated 220 circuits for tools), plus 1 220v 30amp for the cnc...will make 5 separate 240v circuits total. I also added 2 more 110/20amp dedicated outlets to run the computer and controller box off of.
Anyways, the 6/3 (grounded at the garage, no ground running back to house) is direct buried as I found out today. Am I right to think that a 125 breaker is the highest you can go to branch off the main service to feed an out building? I am trying to decide between 100 and 125. There's a decent 125 box at the borg with plenty of slots that should work well.
Any definite word on wire size? For 100a I have read/heard that 3awg copper is fine (buried 18" in 1.25" pvc), but some places I read you need bigger...
I'm thinking to get that 125amp subpanel regardless and either get 3/3 or 2/3 copper and size my breaker to match whatever wire I end up getting.
Any recommendations?