User's Manual

A PDU A failure:
• Disables the power distribution circuit
• Removes power from the left side of the rack
• Disables disk enclosure PS 1
• Disables controller PS 1
PDU B
PDU B connects to AC PDM B1–B4.
A PDU B failure:
• Disables the power distribution circuit
• Removes power from the right side of the rack
• Disables disk enclosure PS 2
• Disables controller PS 2
PDMs
Depending on the rack, there can be up to eight PDMs mounted in the rear of the rack:
• The PDMs on the left vertical rail connect to PDU A
• The PDMs on the right vertical rail connect to PDU B
Each PDM has seven AC receptacles. The PDMs distribute the AC power from the PDUs to the
enclosures. Two power sources exist for each controller pair and disk enclosure. If a PDU fails, the
system will remain operational.
CAUTION: The AC power distribution within a rack ensures a balanced load to each PDU and
reduces the possibility of an overload condition. Changing the cabling to or from a PDM could
cause an overload condition. HP supports only the AC power distributions defined in this user
guide.
Figure 19 Rack PDM
1. Power receptacles
2. AC power connector
Power distribution–Modular PDUs 23