Voltage drop

stretch12 said:
I kinda have the feeling , that a service calc then work on vd. We are at the stage jus spitballing #s just know it’s gonna be a 400a se, it’s a big home.
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Just understand that actual draw will be a lot less than a NEC load calc will show, and a lot less than you would think, even if its a "big home". I am guessing that maybe a 600 volt step up step down might be the ticket for your application. Even if you go with 200 amps actual load (which would almost be certainly way Overkill) you would need (2) 500 AL (use the exception for using the grounded conductor as your bonding conductor so no EGC needed) so you are looking at a total of about $4.75 /foot. Thats $1 / foot more than 15 kv MV cable, but MV transformers will be $8000 more. MV is great but many people are scared of it and dont want to get the tools to make up the elbows.
 
'reminds me of this video on a linesman's YouTube Channel. Start watching at 3:38.

 
If you intend to use only low voltage cables you need 5*3 single-phase cables of 1000 mcm copper, in order to achieve 3% voltage drop. This costs about 600,000 $ [only the cables without work].
If you intend to use two distribution transformers of 200 kVA -20,000-30,000$ each one, and 2000' cable of 3*2 awg 6-35 kV of 150$/ft =300,000$. 350,000 $. [work expenses do not include]
 
Julius Right said:
If you intend to use only low voltage cables you need 5*3 single-phase cables of 1000 mcm copper, in order to achieve 3% voltage drop. This costs about 600,000 $ [only the cables without work].
If you intend to use two distribution transformers of 200 kVA -20,000-30,000$ each one, and 2000' cable of 3*2 awg 6-35 kV of 150$/ft =300,000$. 350,000 $. [work expenses do not include]
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Hmmm, why 200kva transformers, why 3 CN cables, and who is paying $50/ft for #2 CN??
 
Sorry,I am not familiar with 240/120 system. I considered a 3 phase system and 240 V rated.
In your case you need 15 parallel cables in each phase and more in neutral when voltage is 120 V.
The 2 phase and neutral transformer is cheaper [as you need only 100 kVA for 240 V]
 
My boss ran a bunch of numbers for new custom resi work a few years back and figured anything over 750' more than likely worth installing utility primary.
 
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