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.

 

[grsthegreat]

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..

yeiks,...your utility company had you do everything except pull the wire. Here in Idaho anything within the house TO THE METER is customer responsibility. From the meter to utility company is their responsibility. They charge $10/foot for trench, conduit and wire. I'm an electrical contractor and even I cant run these wires or conduit or dig the trench.

Also Ive run gas, phone and CATV in same trench allowing for 6" to 12" spacing depending on type of conduit installed. IVE NEVER heard of or seen a sewer line in the same trench. I would guess it would be not allowed as methane gas could theoretically sneak its way into the transformer.. thru the pipes.

 

[Pilot]

Our phone company has a "plow". That's what they called it; I can't find any pics online. Big dozer, a reel mounted up front with conduit going over the top to a vertical blade in back that cut a 4 ft. deep slit and fed the conduit in simultaneously.

Phone & power company workers showed up at 7 a.m., had a powwow for awhile while the power company guys talked to their shop steward about working with the non-union phone company guys, but they got it sorted out.

Work actually started about 8, a pit was dug on each side of the road & they pushed conduit and wire under the road.

Phone guy fired up his dozer with the plow, made a trial run to break the ground, then back to the street. Started plowing in the conduit, the power guys followed (I think that's how it worked; it's been 19 years) and before noon we had power & phone line to the homesite 1,200 feet from the road.

Was a lot cheaper than digging a ditch (I didn't have a tractor) they wanted $2.50 a foot to dig and $1 a foot to bury, plus conduit & whatever each company wanted for their wire and work. Total cost came to about what it would have cost just for the ditch.

A plow is the way to go.

 

[AGGIE00]

I ran 900' of 4" conduit at 5' bury to the pad mount transformer. We installed a caution tape 2' above the pipe and then ran a water line on top of that. Electric company wanted 16k to do everything and charged 9k to convert from overhead to underground, pull the wire, install the transformer and hook up to the 400amp service that I installed.

 

[20 20]

I work for a very large Northeastern utility company in the planning department. .

And you have the ______ to admit it

 

[ch47dpilot]

AGGIE00 let me get this right $25,000 for 900', seems like a lot of cash...... Pilot union and non-union and only took an hour? I've had to work with unions before. Usually it takes them an hr to figure out who's job it is to talk on the phone then another hr to figure out who's suppose to dial the phone only to find out "he's" not there so they need to figure out who can authorize him to come and dial phone. Then there's somebody else who needs to make some other decisions for somebody to do something else and then after about 3 hrs it's their mandatory break, followed by a few hrs work before lunch and before you know it 8hrs later they tell you they have everything figured out and they will be back tomorrow but since it was suppose to be a 1 day job you'll have to reschedule and that they may have time in a few weeks. Unions gotta love them. they have their place but sometimes they take advantage of the situation.

 

[grsthegreat]

AGGIE00 let me get this right $25,000 for 900', seems like a lot of cash...... Pilot union and non-union and only took an hour? I've had to work with unions before. Usually it takes them an hr to figure out who's job it is to talk on the phone then another hr to figure out who's suppose to dial the phone only to find out "he's" not there so they need to figure out who can authorize him to come and dial phone. Then there's somebody else who needs to make some other decisions for somebody to do something else and then after about 3 hrs it's their mandatory break, followed by a few hrs work before lunch and before you know it 8hrs later they tell you they have everything figured out and they will be back tomorrow but since it was suppose to be a 1 day job you'll have to reschedule and that they may have time in a few weeks. Unions gotta love them. they have their place but sometimes they take advantage of the situation.

900 feet should have cost between $7,000 - $9,000 by all accounts, but I'm not privy to what else they had to do to get power down to you (switches, transformers, line extensions, etc). As far as unions go, i used to belong to the electrical union, and i thought they were great. At least in Wash state, there was no lying around and doing nothing. We started at 7:00AM (SHARP) had 30 min lunch and got off at 3:30 (SHARP). No overtime, no shirking of duty. if you didn't work hard, you were gone the next day. Not all unions are corrupt and lazy. I got a fair wage and full benefits. The owners of the job got a nice product.

Im not union anymore, but i wont put them down. Oh, we occasionally worked a job with non-union workers of other trades, and there was no hostilities.... chatted with eachother just fine. Some states are harsher than others.

OOPS" what did this rant have to do with the OP's original post...cant remember what that even was hehe:laughing:

 

[AGGIE00]

Sorry, I see the confusion. They took off 7000 for the conduit that I installed myself which only cost me 1500 for the conduit, equipment and labor.