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How to wire? - Back fed Dry type 3 phase transformer - 240 to 440v


Oct 11, 2021
I have built a RPC and recently got a 440v EMCO lathe that is rated for 4A. I have this dry type 9kva power transformer (image attached). I'm wondering:

1) Do I connect my 240v lines - l1, l2, l3 to x1 x2 x3 and leave x0 floating? If so, how do i run a safety ground to my machine?

2) There are three taps on each leg of the transfomer "output" H terminals (480v, 456v, 432v), Can I use this to my advantage to adjust my generated leg voltage? or should they all be connected to the same respective terminals?
3) I'm worried about the 208 low voltage side, my line voltage is actually 250v, so 16% higher than 208. not sure how much of an issue this is.. Can I wire 120 single phase to the transformer and then feed 480 single phase to my rpc?


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