Electric Advice Please from the GS

[TKRanch]

OK, building a new barn and running elect service from the house to the barn. Need to run 100 amp service to the barn, but barn is 400 feet away. What size wire to use that best fits the drop off I will experience. I have spoken with several electricians up here and got different answers from #6 to #2 copper, 4/0 aluminum and then something called 12/2???

Don't trust these folks up here and hope the good ole boys from Texas can help a brother out to get going in the right direction!!!

Thanks for any help!

[sports]

Not an electrician..... But first question is are you planning on running it overhead or underground?

[TKRanch]

Good question! My bad, will be underground, under this freaking frozen tundra!!!

[Killer]

If you are going to have 100amps actual load up in the barn you will need to run 4/0 aluminum or 2/0 copper. If the load will be less you could get by with smaller wire.

I assume you are going to install a 100amp main, but your actual load will be quite less than that at the barn itself. If that is the case you could run smaller size wire.

400ft is a long ways to run low voltage service wire. The voltage drop gets you.

[Txjourneyman]

[ATTACH]658856[/ATTACH]

[Txjourneyman]

Here is the other page you need.

[npe001]

The 12/2 Romex will be used to run the lights, plugs, switches once you get into the barn. The #6 that was stated has to be for the ground, not for the actual 100 amps. I came up with a 4.52% voltage drop at 240v would bring you to a 3/0 Aluminum. I would go with either an MBL which would have the ground already wound in with the other conductors or the URD that would have you bring in your own ground. Both of which can be put straight into the ground without pipe ( would bring out of the ground with pipe)
Hope this helped. The total load amps will be about 80 amps or so. 4/0 will give you the full 100amps.

[TKRanch]

Once again the Green Screen comes through!! Thanks so much to you guys. I wish I understood more about electricity! Only thing I know is that I can't see it, it moves really fast and bites HARD! Thus I leave it to the experts!!!

Again, this falls in line with some of what I have been told up here and very much helps me to know better about what I need to know!

We will not need the full 100 amps at the barn, likely needing more than 50, but less than 80 as it looks now. Have a directional boring guy coming out to the house this evening to take a look at how much $ it will be to do that instead of trenching, but am betting it is going to be a bank breaker and we will likely trench. May have to bore under the small creek though, so hopefully it will all work out.

Thanks again!

[dpatterson1976]

Where are you going to purchase the wire?

I just did 150' of 4/0 URD Alum Triplex to my shop. Found it online for much cheaper than my Electrician could get it for.

http://www.ebay.com/itm/400-Sweetbriar-4-0-Triplex-Aluminum-URD-cable-Direct-Burial-/151109463238?pt=LH_DefaultDomain_0&hash=item232ed36cc6

This is the guy I got mine from, free shipping too.

dp

[enewman]

Not trying to hijack but remember. If your sub feeding from another panel it requires 4 wires not three. Two hots a neutral and a ground. For 240/120.

If your doing the work. It saves you money to buy yourself. If your buying it and having a electrical company install. You save very little. Most company's still charge you a mark up on material either way.

Also yes aluminum is cheep. But it has it's down falls especially if direct burry.

[Mike D]

[ATTACH]659114[/ATTACH]

[Gummi Bear]

For 100A service, 400 feet away, you will need 3/0 copper, or 250kcmil Aluminum. This is 2.93% voltage drop from the main panel to the shop (3% is acceptable).

This is found using the voltage drop calculator on the Southwire website.

Aluminum wire works fine as a feeder conductor, and will save you some money over copper. You will have to go up a size or two for your conduit. Usually it works out to be less expensive overall to run aluminum.



As for wiring within the shop itself, I prefer to run EMT conduit in metal buildings. I put my devices in 4² or 4-11 boxes with industrial plates, and use MC as lighting fixture whips. Concealed within walls, I use MC.

I'm a master electrician, and have wired several barns and shops, including my folks' place. I've never had any problem doing things this way, and when I want to add or change something it's not a big deal to yank another wire in the conduit I purposely oversized in the beginning.

[Mike D]

For 100A service, 400 feet away, you will need 3/0 copper, or 250kcmil Aluminum. This is 2.93% voltage drop from the main panel to the shop (3% is acceptable).

This is found using the voltage drop calculator on the Southwire website.

Aluminum wire works fine as a feeder conductor, and will save you some money over copper. You will have to go up a size or two for your conduit. Usually it works out to be less expensive overall to run aluminum.



As for wiring within the shop itself, I prefer to run EMT conduit in metal buildings. I put my devices in 4² or 4-11 boxes with industrial plates, and use MC as lighting fixture whips. Concealed within walls, I use MC.

I'm a master electrician, and have wired several barns and shops, including my folks' place. I've never had any problem doing things this way, and when I want to add or change something it's not a big deal to yank another wire in the conduit I purposely oversized in the beginning.

C'mon Jason, try to keep up ^^^^^.

[Eric T.]

Make sure you remove the bonding between your ground and neutral in the sub panel(because it is not your first means of disconnect), and drive a ground rod at your barn with a grounding conductor from the sub to the ground rod.

[TKRanch]

Man, all great information guys, very much appreciated!! I knew I could count on the Green Screen! I have now had three electricians out to take a look and give estimates and one more guy out tomorrow to look at the trenching. Just amazing the difference in quotes on this job!! Aggrevating, but a learning experience for sure! Will get it figured out and very much appreciate all the help from you guys!!