Firstgens.com

Hey all,

Since my summer rebuild project has stalled, I've decided to tackle another problem. I need to do some welding on my subframe, and my garage is severely underpowered for that. I only have one 15A breaker to the garage which ain't gonna cut it.

So I'm running a 100A trunk from the main panel in the basement up and out to the garage, which is about a 25' run. I've got the panel and necessary breakers - 1 50A (welder), 2 15A, 1 20A. I'm putting a dual pole 100A breaker from the main panel to bring 110/220 to the garage.

My question is - what wire to run from the main panel to subpanel in the garage? I've searched online and found either #4 or #3 cu wire. Also looks like 1 1/2" conduit is required, which seems kinda big, but so is the wire. Any suggestions would be appreciated.

For now I'm just gonna hook up the 50A plug for the welder. My neighbor has a Miller 210 I can borrow to weld a couple of things and get going.

Thanks!

I did an overhead hook up to my detached garage a while ago. I went to look at the left over wire to see if it was marked with a guage, but just a date. The OD is about 1/4" maybe 5/16, use stranded wire not solid. Everything else, panels breakers etc. the same as you wrote with no issues. I want to say it was #4 but I really do not remember. The longer the run the larger the wire needs to be. Mine was about 50' or so in total.

I did a similar deal in my garage buyt I don't recall exactly what the wire gauge was but I think I ran two #2(pretty sure I went heavier than needed becasue that gauge was available for free) and a #10 ground. I know I used 1" conduit to make the run from the inside panel into the garage about 5' away. everything I did I ran past a union electrician buddy first. I will pull the panel front tomorrow for you and let you know

if you do a search, i've seen charts os amps/wire size vs distance.

Wish I had that kinda power available. I put a 30 amp receptacle on a 20 amp line for the bus, cause I was melting adapters... with the fridge, battery charger, and one of two A/C's running, I'm pulling 21-25 amps, and am only getting 109 volts under than kinda load.

Jim you need a big generator, use it for the bus and when the power goes out with this increasingly wierd weather you'll be covered.

A minimum size for 100 amps is a #4 copper for the conductors and a # 8 copper for the ground per the NEC.

Hmmm, the bus has a big generator... 8000 watts, diesel, variable speed inverter genny. 2 50 amp circuits. Don't think it's actually wired for 220 volts though, 2 125 volt circuits.

Never thought anought bringing it out of the bus though?

Thanks - I thought it was either #4 or #3 copper for the hots. That's some pretty big wire to pull though conduit. Good thing it's a short run.