i only have a 3 wire outlet by my mill... hot hot ground... no neutral.
But i have a few devices that want 110v power, primarily my 24v power supply to controll my contactors and relays for my phase converter.... my choices are....

1. run a seperate 110v wire to the mill as well to power the 110v items.

2. use the ground as neutral, and power the 110v items between L1 and ground. (old school before they had neutral and ground)

3. run the 110v items in 220v mode (european mode) and then wire them with the hot hot ground just like other 220v things. i assume this would work, but never played around with the 110/220v switch on things like that... but i dont know if europe gets its 220v on a single hot, and still has a neurtal and ground... or if it uses 2 hots and a ground like we do... that is what i am curious about.... or if it even maters.