Patent ID: 7851950

Claim:
A power distribution system for computer systems in a computer room of a data center, comprising: a first transformer configured to transform three-phase source power to three-phase intermediate power; a second transformer having secondary windings in a Y configuration, the second transformer configured to transform the three-phase intermediate power to three-phase operating power at operating phase-to-neutral voltages between about 220 volts and about 260 volts; wherein the first transformer is configured to step down the three-phase source power to intermediate phase-to-neutral voltages that are lower than the phase-to-neutral voltages of the three-phase source power but higher than the phase-to-neutral voltages of the three-phase operating power, wherein the second transformer is configured to step down the three-phase intermediate power to operating phase-to-neutral voltages that are lower than the intermediate phase-to-neutral voltages; and one or more power distribution units coupled to the second transformer, wherein at least one of the power distribution units is configured to supply operating power from the second transformer to a plurality of computer systems in the data center.