HP D7171A - NetServer - LPr Manual page 43

Chapter 2
Power Supply Redundancy and Power Cable Non-Redundancy
When two HP NetServer LH 4r units are loaded in a single rack, power supply
redundancy is possible. To achieve power supply redundancy, a fourth power
supply must be installed in each LH4r. However, there is no power cord
redundancy. Therefor, plug both power cords for one unit in to one PDU-UPS-
branch circuit. Doing so maximizes current carrying capacity and minimizes the
possibilities of a chain reaction in the event of one branch circuit outage.
High Density Configuration
A high density 208 VAC configuration is illustrated in Figure 2-12. For this
example, one 41-EIA Unit Rack (a 2 meter HP Systems or HP System/E rack) is
completely filled with power supplies, servers, and storage units. Two mass
storage units "sandwich" each NetServer.
NOTE
For high-density configurations, choosing a higher line
voltage will reduce the number of PDUs needed to power your
rack solution.
Connecting and Routing Cables to the HP NetServer LH 4r
39