Price between 3Ø and 1Ø

I just completed a large apartment complex design with 3Ø. The developer just asked for us to consider changing the entire design to 1Ø... I need to get a better understanding on the total price difference between the two services. After speaking to the utility company..
(8) 208 1Ø 100kva transformers are around $5k-$6k each=$40k-$48k
(4) 208 3Ø 300kva are around 12k each. =~48k
3Ø requires an extra feeder.

Changing out (150) 208 1Ø unit panels is pretty much a wash between (150) 120/240V Ø

The only price difference left would be utility switch gear at each building. Currently designed for (8) 1600A 208v 3Ø. I'm guessing we will need to swap out for (8) 2400A 1Ø switch gear. Does anyone have an idea on what these things cost?

Thanks!
 

texie

Senior Member
Why are you not using 3 phase meter banks with single phase apartment feeders? I've rarely seen it done any other way in this size range. And I can't imagine the POCO would give you a single phase service this large.
 
Why are you not using 3 phase meter banks with single phase apartment feeders? I've rarely seen it done any other way in this size range. And I can't imagine the POCO would give you a single phase service this large.
We are using 3 phase main utility pull with single phase meters/stacks for apartment and 3 phase commercial stack on the same set for house panels. The problem is the units are divided up into multiple buildings so in the utilities eyes its 8 different designs/permits/service locations.
 

Cow

Senior Member
Location
Eastern Oregon
A 2400A single phase service over here would be a nonstarter.

The utilities won't install a transformer they don't keep in stock that in turn they would have to keep a spare for. We've ran into it a couple times on large 480v services that got up to bigger than standard transformers.

208v 3 phase is the only way to go in my opinion.
 

infinity

Moderator
Staff member
Location
New Jersey
The POCO is willing to provide you with 2400 amp 1Ø services? Around here that likely wouldn't be an option so as Cow stated you would need to go with 3Ø, 4W, 208Y/120 volt services.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Wow.. 250 single phase is the biggest we keep.
beyond that you divide services or go three phase.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I am confused about the 1 phase 208 transformers. Wouldn't it be either 208y/120 three phase or 120/240 single phase?
That’s what I think. I assumed the OP mistyped.
i am referring to a 250kVA 120/240 single phase.
otherwise it’s three phase like everyone suggests.
 
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