JoeStillman
Senior Member
- Location
- West Chester, PA
The 12,000 ft is probably over private property and so the utility won't want to run the line. On the other hand, 90 kVA may not be enough for the POCO's primary rate tariff. But that doesn't mean a privately owned overhead line can't do the job. 2.27 miles is too far even for 600V. I'd go 4160V with overhead lines. If the POCO won't give you primary, then buy 2 transformers instead of one.Hasn't been mentioned, but....
Buried or overhead?
The original sounds like buried, but that's a LOT of trench and a LOT of fault possibilities. And up-sizing the wires vs overhead. Overhead will be a lot easier and cheaper if it's an option.
Maintenance.
If the PoCo owns the line, they'll charge something for the privilege of having it but will also have everything needed to repair when it gets hit by lightning. And they get to size the wires as they see fit (NESC) and not be constrained by NEC sizing.
I wouldn't consider taking a service at the end utilization voltage for this if there was any other option. If the PoCo won't extend their line to the site, maybe you can take a primary-voltage service connection from them onto customer-owned lines and transformer at the end site. The cost of MV switches and metering might well be offset by the cost of the lines themselves.
Have you talked to an engineer at the PoCo about options? If all they're offering is 240/120v that kinda sounds like the business office answer.
Best cost, IMHO is medium voltage overhead.