Data General must have thought they had a better idea on redundancy, for my memory (fading) says they were 120 volt single phase. If it weren't for the draw on each, you could loose 2 phases and they could have remained up. As it was, two would handle the load if for some reason you lost one phase. However the motor generators providing clean power took care of any single loss of a phase, we weren't into UPS's until just before the time DG lost the contract to IBM.

Shane