Transformer calc question

[Skubie]

I have a 480V, 100A service that I need to step down to 240/120V. What kind of transformer do I need and what will its rating be?

Thanks

 

[GoldDigger]

I have a 480V, 100A service that I need to step down to 240/120V. What kind of transformer do I need and what will its rating be?

Thanks

What kind of 480 service do you have? Three phase or single phase. It will make a difference. The rating will depend on what loads you will be driving from it. Also, do you need both 120 and 240, or specifically 240 volt split phase (120-0-120)