I'm not using a Fadal transformer. I had a T820 and took it out. I do have a transformer in there, but, it's just step down isolation transformer (240 volts to 120 volts), that I got on Ebay. I actually had this running with no transformers...hooked it up straight to my breaker box on 240 volts for the spindle drive and the axis drives and 120 volts for all the rest.
If you look at the schematic for the Fadal single phase xformer, it is only used as a step down xformer for the electronics side of the mill. The spindle drive and axis drives are actually hooked straight to your breaker box. There are two A12 and B12 leads, one set ( A12 and B12) for the spindle and the other set (A12 and B12 for the axis drives. Both A12's go to one side of your supply and the B12's go to the other side of your supply. The C12 leads are just capped off. The leads marked A16, B16 and C16 are 120volt. The leads marked 15 are neutral.
Now mind you, my supply voltage in the garage is about 235 to 239 volts single phase. Fadal also stipulates 230-240 VAC. If you have the required measured voltage, you should be able to make the switch