Need shop electrical help--subpanels and amps???

[james]

Finally got a 220v mig (from my 110 lincoln.) I have no power ('cept a single 110 outlet) to my carport, uh, I mean, high dollar shop http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif . So, I was going to run a subpanel out near the shop. I have 150 amp service to the house, and a few empty slots. (4). Two I was going to save for later when I put in central a/c, so I can take the other two empty slots and run 220 to a small sub, right? I've got about 40 feet or so to run, what gauge wire should I use? I plan on burying it, plastic conduit, right? (I'm in florida, no ice heaving to worry about) What amps should the subpanel's main be? The welder is rated at 250 amps, but that is output, the input at 200v is 40amps, so should the welder than be on a 40amp breaker? I'm also going to run a few more outlets and flourescent lights on this panel (outlets for shop tools, only one 220v outlet for the welder.) Would 100 amp panel be okay? Like I said, I've been using a single 20amp outlet for my "shop", including my welder, so I'm not planning a full machine shop, just an outlet for the new welder and it'd be nice to have lights and a few more outlets. Thanks!@!!

[Rusty]

A sub panel is definately needed. I would run a 100 amp service from your house. You can get direct burial cable from your local Home Depot or hardware store that carries electrical parts. Just tell them you will be running a 100amp service. Your welder will be on a 50 amp service so you always plan on a little extra. You will probably never use 100 amp but if you put a 40 or 50 amp service you will probably end up tripping the breaker in your house. You will get sick of that. Since this is an attached building you will also need to set a new ground rod at the building and ground your panel to the ground rod. This is to protect you and your equipment. Hope this helps you.

[John B]

I see an electrical service upgrade in your future. Are your empty spots on your panel in phas?. I mean next to each other? What all do you have running off the existing panel?

[james]

The existing panel? Lights, outlets, stove, dryer, all the normal house stuff. I have two empty slots on one side, three on the other.

[james]

It's a 70 year old small house, not a lot of electrical appliances.

[dixiedog]

James what brand is your panel and how old is the house? Federal Pacific, Square D, Seimens...? And you don't have central a/c unit, are any of your appliances gas? What about heat for the future, will it be gas or electric?

A lot of questions but this will help me make a recommendation

[james]

All appliances are elec, no gas. Wall shaker ac units, and no heat. About 3 nights last year we plugged in a little elec. heater. No plans for heat, don't need it. Don't know what brand the box is, heres a pic. Home depot carries the breakers, though. The house is 1930, but I'd say most of the wiring is from the 80's. I've owned the house 7 years and had zero probs with the electric, Just looking to put some juice out back. I have a dedicated 20 amp outlet out back already from an old well pump. That's the outlet I use for my 110 welder and no probs ever. I went to Home depot this morning and think I have it figured out, but I welcome any suggestions (except a full upgrade--no funds for that right now)