Single phase 120/240 step up to 480v

[Natfuelbilll]

I have a large site where motor loads are 450feet from the service.

I would like to take 240V off the 120/240 service through a transformer to 480V, and send the 480 to the motors.

Can a common 100kVA single phase transformer be reverse connected to step up from 240V to straight 480V?

 

[Cold Fusion]

... Can a common 100kVA single phase transformer be reverse connected to step up from 240V to straight 480V?

Unless the xfm is weirder than normal, sure. But that only gets you a 2:1 reduction in the copper. If you are going to buy two transformers, go with 575V.

OR

Have you considered 2400V?

cf

 

[jim dungar]

ICan a common 100kVA single phase transformer be reverse connected to step up from 240V to straight 480V?

Yes.
But aren't your 480V motors 3-phase?

 

[Natfuelbilll]

Single phase power will supply an appropriately rated VFD that will output three phase to the motor.

 

[Cold Fusion]

Single phase power will supply an appropriately rated VFD that will output three phase to the motor.

Whoops - scratch parts 2 and 3 of my answer.
cf

 

[LarryFine]

That's gonna be a heck of a 240v 1ph load back at the point of origin.


Added: Have you looked into getting utility run to the load?

 

[Natfuelbilll]

I had not considered that. But you know it really is a great idea for this project. Thanks a Billion Bananas

 

[LarryFine]

Thanks a Billion Bananas

Mmmmmm! Bananas! :roll:

 

[templdl]

Personally I would go with an approporately designed 240v-2400 1ph transformer to step up the 240v to 2400v. Then use a 2400v to 120/240v step down.
A properly designed step up transformer will be designed with reduced flux which reduced the inrush. One would like to think that if a transformer is feed from the HV side or LV side that the inrush would be proportional but they are not. The inrush is higher on the LV side because the LV winding are commonly next to the core of the transformer.
A reduced flux design commonly uses more iron in the core and adds about 10% to the cost of the transformer. This is important to consider as it it is overlooked there is a posibility that the primary breaker would trip when the transformer is energized.
2400v transmission is commonly used at air ports where longe cable runs are common.
It is also imopport that you use all of the latitude you can get for the primary OCPD as allowed per art 450 of the NEC.