Pole Building Progress

PTRich · Nov 6, 2001

Bill:
Love the building, I am siding mine now and had a few question's maybe you or someone else could help me with. I plan to run water outside the barn much like yours. I want to run a 100 amp sub-panel in the barn. My power line will be about 100 feet. I was thinking about running 2 gauge aluminium or 4 gauge copper in conduit. Does this seem adequit for that panel? I realy do not think I will ever run more than 50 amps at one time but I like a larger panel so I can have a lot of seperate breakers. Should I run a ground to the panel or sink one at the barn, or both? Can you run your phone line and cable in the same conduit as the power?

Thank's PTRich

bgott · Nov 6, 2001

http://www.elec-toolbox.com/calculators/voltdrop.htm

According to this, #4 will do it.

Bill_in_MI · Nov 7, 2001

PTRich: Your proposed wiring sounds right to me...but I will defer to others more expert in these matters. Just make sure you don't put a larger breaker in your main panel than the rating of the cable/installation. You should be ok voltage drop-wise at 100 ft. I am running a separate ground in my conduit. Don't know about creating a new ground at the sub-panel. Putting the communications cable in the power conduit is probably in violation of most codes, and not a good idea from an induced interference standpoint. Recommendations are to keep the communications cabling a minimum of 12 inches from the power, and cross only at right angles if crossing is necessary. I am running one separate conduit for telephone and coax. Always a good idea to run a pull line as well if you ever have to put another line in.

Hope this helps some.

MossRoad · Nov 7, 2001

Check with your local code before you run anything.
The code people here even helped me plan it. I installed a sub panel in my garage. The inspector came out, and all was according to his plan. OKd it in 5 minutes. I'd stay away from aluminum if I were you. Also, I ran a 2 inch conduit and a 1-1/2 inch conduit. Big one for power, little one for 2 cat 5 cables(phone and computer) 3 RG6 coax (2 from satellite dish mounted on garage to house distribution system, one for signal back to garage TV). Here there is a specific minimum distance that you have to keep between electical, water and gas lines. They cannot be run in the same trench. Hope this helps. /w3tcompact/icons/smile.gif

<font color=green> MossRoad </font color=green>

MossRoad · Nov 7, 2001

If you put a larger breaker in your panel than the cable is rated for, the cable will burn up before the breaker trips, won't it?

<font color=green> MossRoad </font color=green>

cowboydoc · Nov 7, 2001

PTRich,
When I do barn we always just run the outdoor wire rated for the number of amps that you want to carry. I don't ever worry about putting it in conduit as it is usually 2.5' deep and you don't have to worry about anything with it there. Alot of expense for nothing. Also think of everything that you want to run out there first. Now and in the future. I know alot of guys who wished they had 200 amp service boxes as they ran out of power and have to shut this and that off to run this or that. You'd be kind of amazed how much everything together adds up to especially if you are going to use it as a shop and have heaters, air compressors, welders, etc. going.

I don't think there is any problem running all the wires in the same trench. With a metal building be sure you have it all grounded right. If you don't it could electrify your whole barn if you ever get a short. You absolutely have to have your barn grounded at the panel. You need to stick in a grounding rod at least 4' deep.

Bill_in_MI · Nov 7, 2001

It's a potential hazzard to say the least. I believe my suggestion in the previous post was to not put in a larger breaker at the feeding panel than the wire was rated for...at least that's what I intended to say. Sorry if I was confusing...my wife tells me I can get that way.

zenmek · Nov 7, 2001

PTRich, definitly have a seperate ground rod for your building, if I am not mistaken the National Electrical Code states this as a requirement. Any way you want your ground circuit to be as low as resistance as possible and a 100' run back to the main panel will increase your resistance and could cause a potential between the building and ground, you won't know it until you touch something /w3tcompact/icons/shocked.gif! Better safe than sorry!!!

PTRich · Nov 7, 2001

Thanks for the help. I think my plan for now will be to run 4\3 in conduit 2 and a 1/2 inches at 3 feet, seperate grounding rod at the barn. Cable and phone in black pvc roll well pipe at 18 inches. I will leave rope in both. Seperate trench for water.

Thanks again: PTRich

Phred · Nov 7, 2001

Bill,

Why four to five feet deep?
Does it freeze that deep in your area?

I just finished a trench from my well to my new building.
One days work with a ditch witch for ~165' 22" deep trench (see attached). Total cost ~$100 for the rental.

I think this is about as deep as this machine can go. Probably not good enough for MI, but hopefully good enough for AR.

Fred