I have just purchased a 6 acre piece of land with no buildings. It has electric service to a pole about 100 ft. from the road with a meter. No wiring on the downstream side of the meter. I want to run an underground service in a 3 inch conduit about a quarter mile past the meter to my building site. I will hire an electrician to install a 200 amp service at the new house site. what size wire will I need to run the quarter mile from the meter to the house site? Thanks in advance for any assistance, Morrie

 

You would be best advised to get the power company involved. I would see if they will set a transformer closer to the house.

 

A lot of cases the power company will only provide what you have in rural locations. PCboss's suggestion is a good thing to check, but installing a transformer might be on your end.

In case it is not clear, you have to tend with voltage drop at that distance. At 1320' and a 100 amp load you would need 500mcm copper wire for 5% voltage drop.

 

At 1320 ft even at 480V you would need something in the area of 250KCM copper for a 100amp load. You stated you wanted a 200amp service. Over the years I have done several services for communication companies and large ranches where the distances were up to five miles from the utility. I would suggest you contact an electrical or utility contractor who can do HV Splicing and has experience with back-feeding the oil-filled rural utility pad-mount transformers. You take a 200amp service at the service pole and back-feed the pad-mount transformer, boosting the voltage to 5kv and run a single cable with concentric ground to your site location to the primary of another equal size pad-mount 5kv, transformer, droping down to the 120/240 for your residence where you can then have the full 200amps. You can also have feed-thu bushings that would allow expansion of the 5kv system in the future if the property is large and another building is added at a longer distance. The rural utility xfmrs are totally enclosed and secure providing a safe installation. Bottom line is you should get some professional assistance, it will save you money in the long run.

 

If the utility won't extend the primary then bahtah's suggestion is, in my opinion, the only thing practical to do.

 

Agreed. This distance is just too long to be thinking about running at 240V. You'd be in the neighborhood of $10,000 just in aluminum wire (no trenching, conduit or other equipment) to get less than 100A back there from the road.

 

That is definitely a good suggestion, but I think before I went ahead with boosting the voltage at the meter and dropping it again at the home site I'd first inquire about primary metering. If the power company agrees to this you could have your contractor install an underground high voltage feeder and padmount transformer at your new home site. Your meter would remain at the existing pole and you would probably get a discount for furnishing and owning your own transformer.

 

That's true, Joe but unfortunately if you own your own transformer with primary metering you will also be paying for the losses of that transformer and IF you need a high output on occasion but generally have the transformer lightly loaded the transformer losses can be significant. This is why the utilities use the smallest distribution transformers they can get away with.

 

Good points, Furd, but I was also thinking of the initial cost of two transformers and the losses involved. Primary power can usually be purchased on a commercial basis at a significant discount. I suppose it also depends on whether the power company will even allow primary metering for a residential service.

 

Thank you much for all the advice and comments. I did take the advice of consulting a professional. I talked to a friend, a retired lineman, who has installed such services and also a friend with a rural home as far off the road as my site and both said the same thing as "bahtah" suggested below. Time to contact my power company. Thanks again