Patent ID: 8902569

Claim:
A system, comprising: a rack; one or more computing devices coupled to the rack; one or more rack PDUs coupled to the rack, wherein at least one of the one or more rack PDUs comprises: an enclosure; two or more power input receptacles mounted on the enclosure; and two or more power output receptacles on the enclosure, wherein the two or more power output receptacles are configured to supply output power to at least one of the one or more computing devices; a phase match detection device, wherein the phase match detection device is configured to determine whether a phase of input power fed to at least two of the two or more power input receptacles matches within acceptable limits, and when the phase between input power to the at least two of the two or more power input receptacles does not match within the acceptable limits, the phase match detection device is configured to inhibit an electrical connection between the at least two of the two or more power input receptacles; and one or more power cables coupled in at least one of the two or more power input receptacles on the enclosure, wherein at least one of the one or more power cables is configured to supply the input power from an electrical power system to the at least one of the one or more rack PDUs.