Re: power quality
marcspages,
I'll try. Basically, as I understand it, common-mode filter elements (capacitors) for a Y-based power system shunt common-mode noise to the ground plane. But they are only as effective as the total impedance of the ground system. A 220-230-240 two phase, (L1 & L2, each 115 volts to neutral) can be easily filtered by placing a capicator across the phases.
So as the origional question, is/can a 220 volt system be better for an IT system, my opinion is yes. Several power conditioner companies call it "balanced power" and claim a 15-dB reduction is system noise.
regards,
MM