Need 400V 3phase for CNC machine, best approach?

[seandean]

Just got a DMG Mori machine delivered and it calls for supply power of 400V x3, N, PE (protected earth). My shop has 208/120 3phase power and I was planning to buy a local 480V to 208V delta Wye transformer and simply backfeed it as well as adjusting the taps to get below 440V.

Wiring diagrams for the machine say this:
"Isolating transformer necessary if:
--- voltage <360V
--- voltage >440V
--- TT main
--- IT main "


With losses from backfeeding the transformer, I should be close to 400V on tap7 according to the diagram: https://i.ebayimg.com/images/g/HGMAAOSw1eFdgmnC/s-l1600.jpg


But with the machine requiring a Neutral, is it possible to wire the high voltage side of the transformer in WYE configuration also ?


I read several threads on here before making this post, I just wanted advice on this specific application.

Any help is much appreciated!

-Sean

 

[Dennis Alwon]

[noparse]I am closing this thread, in accordance with the Forum rules. This Forum is intended to assist professional electricians, inspectors, engineers, and other members of the electrical industry in the performance of their job-related tasks. However, if you are not an electrician or an electrical contractor, then we are not permitted to help you perform your own electrical installation work.


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