I'm putting new 200 AMP electrical service into an 80' x 70' pole barn. Of course, the box and service is in the NE corner and the area I'd like to use as a shop is the SW corner.

I know I can run Romex from the box all the way across but that'll get expensive pretty quick with all the electric I want in the shop. What would I need to run from the new 200 AMP box to another box in the shop area so I could run the shop electrical from breakers in the 'shop box' rather than running them all from the main box and how I should go about doing it?

-- Gary in Indiana (gk6854@aol.com), October 25, 2001

Answers

Add up all the wattage you can antisipate even needing plus a safety margin, calculate how many feet of distance and post that info here again, I am sure there is someone with a wire chart out here.

-- mitch hearn (moopups@citlink.net), October 25, 2001.

I'm going to say I'd need 150' of whatever gauge to run to a 'shop box.' As far as total wattage, I have no idea. I'd be lighting the shop, running tools, maybe an electric lift/hoist, fan(s), possibly electric zone heat and maybe a water heater. I'd like to feel like I can run a welder (not that I know how to weld) without worrying about it. Essentially, I guess I'd rather run heavier than I need and spend a couple dollars more than worry about having a heavy enough wire.

-- Gary in Indiana (gk6854@aol.com), October 25, 2001.

I would slave in at least a 100 Amp box in the shop area. A welder requires 220 VAC, so if that is a real requirement just have the electrician slave ANOTHER 200 box with 220 in the shop area. Who does the work depends upon your insurance and local electrical inspection requirements.

-- Joe (CactusJoe001@AOL.com), October 25, 2001.

Gary, I had a similar situation,the main service here is 400 amp.split at the barn.200 at the barn and 200 at the house.So when we added the other barn/workshop I ran a 125 amp sub panel to the new barn.I know this adds up to more than 400 amp total,but theoretically the system should never see that much of a load.In the work shop we ran 2 20amp circuits for duplex outlets(radial arm saw,drill press)1 15 amp for the light circuit,1 20 amp 2 pole for a compressor and a 50 amp 2 pole for the welder drop.I also run most of the drops in EMT,not that its code I just have access to the fittings and it makes a clean looking job.......

-- Steve in Ohio (stevenb@ohiohills.com), October 25, 2001.

Hire an electrican that likes venison, or what-have-you to trade!

-- Kathy (catfish201@hotmail.com), October 25, 2001.

Here's an answer I got via email from a retired electrical contractor who later taught the subject in college. I wanted to include this for the archives as it pretty much tells me everything I needed to know so I hope it can help someone else, too.

"I'd run 100 amp wire from the main panel to the "B" panel. Using copper----#2-2-4 in T, TW or THW. This size triplex is with a reduced size neutral--#4. Aluminum can also be run but it's the nest size larger---#1-1-2 with the same letter designating the insulation. It doesn't have to be enclosed in conduit unless you want it to be. 100 Amp should run anything you'd want."

-- Gary in Indiana (gk6854@aol.com), October 26, 2001.

Sounds like you have some good information on your problem. One thing I would like to add is if you start with copper wire stay with it. Aluminum the same way. I found out the hard way about bi-metalic corrosion. If you hook aluminum to copper it corrodes which can cause broken circuits or worse build up heat and cause a fire. There are products available to stop this but why have one more thing to worry about? Dave

-- Dave (drcomer@rr1.net), October 26, 2001.