Question for The Electricians

[GTop]

I want to run 100 amp service to my pole barn. The distance is about 150 feet. I was thinking of going with direct burial. What gauge wire do I need to buy. Thanks

 

[QRTRHRS]

I am not an electrician by trade but I would say 4/0. I will say this, conduit is cheap. I don't know what your plans are but I would lay in three runs of conduit. One for power, one for phone and one for cable or whatever. Or, PVC for the power and 4" drain for the low voltage stuff. Another tip if you do use PVC. Glue the pipe and lay it. When it comes time to pull the wire, tie a plastic bag to a lightweight line and suck it through with a shop vac. Greenlee makes a kevlar line but it only comes in 1250' rolls. Anyway, start small then go to a larger line. Or, the old way, lay out the wires and feed each pipe over them until you get to the end and glue up.



I just did 350' of 3". PPL here in PA wants the depth 39" to the top of the pipe, 2-3" of screenings under and 15" of screenings on top. That is if your concerned with code.

 

[pathaymond]

Yup do as qrtrhrs suggests. Bigger wire will only help small will create trouble. use the conduit incase you have failure down the road which can happen. I always install well pump pull rope in my conduits that stuff is pretty cheap and darn strong. if need be you can hook to the rope with the truck etc for a little help with the pull. 2. 5 inch is the smallest I would run for the power(Conduit size)

Dont make alot of 90*turns we are allowed 2 90 and 2 45 degree elbows. Hope this helps.

 

[illflem]

Not sure if you mean by a new service a new meter from the power company or if you are tying in to your home's meter and just adding a new breaker box. In my area if you run more than 100 feet you have to go with a new meter from the power company, they will dictate what size wire and if you can use direct burial. Direct burial is no longer allowed here except for mobile homes for good reason, too many failures. Here the meter reader is trained to look for new services, if you go more than 100 feet you're busted, they will ask you to remove it or they will turn off your power. I've known a couple of guys who ran into trouble when running home power to a distant well head. Good idea to check first.

 

[Champane Flight]

I have heard

I have heard the max distance was 100 yds? I am hoping for this as the plan on my property calls for 200 ft to the well and 250 to the house from the main drop at the shop. I sure don't want to have three separate drops.

 

[TPCDrafting]

I agree with everything said above. Call your local electrical inspector first and pick his brain on what's the best route to take and what is legal. I did the same for my barn which is ~250' from box to box. I didn't need to run my wire in a conduit and didn't need a permit. So, going on the recommendations above, to answer your question directly, I grabbed my copy of "Wiring Simplified". The 39th edition based on the 1996 electrical code. I bought this at home depot for a few bucks. They also had a copy chained to the shelves for in store use. Anyhow the chart in there say's that you can legally run underground (buryable cable) 1/0 230 feet. That's 100 amp, 24,000 watts at 240 volts. Note that the next size smaller wire (no. 2) will only run 145 feet with some stipulations.

And I quote from the book:

"Note that at 240 volts any given wire size will carry the same amperage twice as far as at 120 volts with the same percentage voltage drop. " (These numbers are all based on a 2% drop. )



Keep in mind, just cuz I bought this book, it doesn't make me an electrician. I would seriously call your local electrical inspector, they were very helpful to me when I did mine.

 

[GTop]

Thanks everyone for the advice/replies. I have a call in to my power company and also the local electric inspector.

 

[d906670]

according to the NEC 2002 #3 copper or #1 alum. (table 310. 16)latest code book. rick