Delta Servo Drive 220V/400V Series
It is connector to connector voltage. It can be line to line if you connect all three phases or it is line to neutral if you connect a single phase (if allowed).
No, you may not use 3ph 400V fo a device that has 220VAC input, only phase + neutral (if single phase is allowed, only low power servo drive). If you intend to connect all three phases 400VAC to your servo drive, then you should use an autotransformer 400/220.
I do think the manual is self explanatory: