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Skyline
01-18-2007, 01:40 PM
As of now, my garage has only 120v, and although I have a compressor and have used 120v welders (either borrowed or rented). I want to step it up to be able to run a 240v welder and a much bigger compressor. I recently upgraded my home's electrical panel, so I should be good there. My problem is that the garage is detached, and at least 130ft from the panel. I plan on a sub-panel in the garage providing bold 120v and 240v breakers. The heaviest 4 pole wire they had at home depot was, I believe, good enough for 50 amps (I don't remember the gauge, but I did check a chart). I do have a pair of empty 3/4"id plastic conduit already burried between the house and garage, so hopefully that will be enough to carry the wire I need. Will this 50 amps be enough?

nate
01-18-2007, 02:31 PM
If your actually setting up a "shop" in there, I'd run 100amp service at least. Most houses are 200amp service now a days, so shouldn't be too much of an issue.

You need to think of all the things you'll be running possibly at the same time and figure the power you need. The welder alone would be ok on that 50 amp line, that's about it though.

Skyline
01-18-2007, 02:40 PM
If your actually setting up a "shop" in there, I'd run 100amp service at least.

Any idea what gauge wire I need to run a 100 amp sub-panel assuming a 130ft run? From looking at the heavy wire I saw at Home Depot, that probably means I have to use 4 individual wires as opposed to one big cable with 4 wires inside.

Rubber Chuck
01-18-2007, 03:24 PM
You might have to go to an electrical supply house...not sure if Home Depot will carry what you need. You need to ask for 100 amp service cable. W/ a 130' run...you will have a bout a 6-7% voltage drop...so you will be at approx 95 amps at the garage. According to my electrician buddy that just left the store.....unless you are welding while using the air gun in the shower(Hot water heater running) you will be fine.

Cue-Ball
01-18-2007, 05:31 PM
You will probably need to run 4 individual cables, something in the 4awg range I think.

I am currently doing something similar in my garage. I need to add a sub panel and run cable from the main panel across the attic to the other side of the garage and down to the sub panel.

Going to probably run a 125amp sub (they always seem to stock those ones at my local HD), and that should give me plenty of juice if I ever need it.

I have a 200 amp service to the house also.

drewman141
01-19-2007, 12:12 AM
I'd say for a 100amp sub panel you should run #4 or #3 AWG Underground rated service entrance cable. Even though it will be in a conduit the cable needs to be rated for underground or direct burial b/c of the moisture.