Normally the power is taken to the Mill enclosure and then the wiring, fusing, transformation etc is done in the enclosure.
Why are you doing it the way you show?
Is there any reason not to follow a similar practice than the original, or an adaption of of it?
I am assuming this is a retrofit?
There is nothing wrong in principal with what you suggest but I would suggest you feed the enclosure with 240 1 ph and then split off with a suitable fusing etc to the 120v 1 ph circuits etc.