underground electrical

[ch47dpilot]

Anyone ran med. voltage electrical lines. My future home is about 600' from the pole and would like to run underground. Not a good way to run overhead without ruining the view. Not sure how open electrical companies are to running Med. voltage to a single home and having the transformer 100' from home. Also how deep will med Voltage need to be, me Case trencher digs about 3 1/2 - 4ft deep.

 

[Mace Canute]

You need to talk to your local electrical utility since it's their policy that dictates where they will put the transformer.

For what it's worth our provincial electrical utility here will put a transformer quite close to a house. There is a minimum distance without a blast wall (padmount transformers have been know to violently explode on the rare occasion ) but most people chose to have them a short distance away mainly for cosmetic reasons though. The underground primary cable here operates at 14,400V to ground and our depth requirement for that voltage is 1 meter. If telecommunication cables share the trench, 1.2 meters.

BTW, the ANSI C84.1 Standard defines the medium voltage class as nominal voltages greater than 1000 volts and less than 100,000 volts.

 

[kf4uda]

I am in middle TN so our regulations may be different that yours. I wanted an underground service for the same reason as you. I had to dig a 4ft deep ditch 600ft in length for the medium voltage to a pad mounted transformer. From the transformer to the house the distance was 220ft and 3ft deep. I had to provide and install 3in sched 40 pvc. At each end of the ditch I had to use sched 80 also up the pole and up to the meter base. I had to provide a pull rope in the pipe. The power utility pulled the wire in. My service is a 400 amp (200 to the shop and 200 to the house)

As said contact your local utility. They will probably send an engineer to meet with you. He will tell you what you will need to do which may be a little different than here.

 

[ch47dpilot]

Thanks when I get more info from Electric company I'll let everyone know.

 

[Transit]

Anyone ran med. voltage electrical lines. My future home is about 600' from the pole and would like to run underground. Not a good way to run overhead without ruining the view. Not sure how open electrical companies are to running Med. voltage to a single home and having the transformer 100' from home. Also how deep will med Voltage need to be, me Case trencher digs about 3 1/2 - 4ft deep.

You should have two phase 240/ 120 in the house, 120 + 120 = 240.

I would dig a second trench with conduit well a way from the utility trench for cable TV, fiber and whatever someone will dream up and leave a pull tape in it to pull any new additions
The second trench needs be no deeper than 18 inches BOACA code, but your town may have other ideas.

 

[20 20]

codes will let you know WHAT THEY ALLOW in your area, that is where you need to start.

 

[Ken45101]

As has been said, talk to your local utility.

I had a similar setup on a house we built ten years ago. My contractor dug the ditch, the utility company installed the wire and transformer, no charge IIRC.

One thing, they are particular about the depth. Our was 6" too deep and they made him backfill!

 

[goldenwings]

I work for a very large Northeastern utility company in the planning department. We generally specify that for a primary underground service, the load must be a minimum of 300' from the source. Otherwise you could just run your own secondary cables from the pole, with a pole mounted transformer serving you. For the primary UG service we have a cover depth of 30" with 4" of sand padding around our cable, or conduit with pullboxes. There is a 42" cover if we serve with natural gas as well. At this point the padmounted transformer must be within 100' of your load, with your secondary cables running from the transformer to your load. Now the fun part, we charge about 10 bucks a foot from the pole to the padmount location, and you dig, otherwise thats another 9 bucks a foot. I agree that specific utilities may vary a little, but that probably going to be fairly close to what you can expect, as each state has their own public service commission/ public utility commission etc.

 

[roamerr]

I love my small Electric Coop. 450 ft from pole underground was only $1.10 ft. The transformer on pad is approx 150 ft from my house and tucked into the edge of the woods(it's between my barn and the house since both feed from the transformer). Paid approx $2 a ft from transformer to barn. Underground is the only way to go....

 

[Pirate]

I am in TN too. What I want to do is bury the service to the house from the xfmr to house. It is a short distance, about 40'. Ideally, I would also bury in this same trench a 3" sewer line and more conduit for a drop to my RV. Anyone ever heard of all that being allowed in the same trench? Thanks.