HP Xw460c - ProLiant - Blade Workstation Overview page 28

The c7000 enclosure has three redundancy modes: AC or DC redundant, power supply redundant,
and no redundancy mode. The BladeSystem Onboard Administrator or the Insight Display can be
used to select the power redundancy mode. For more information, the HP BladeSystem Onboard
Administrator User Guide is available at this website:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00705292/c00705292.pdf
.
Since all the power supplies share in delivering pooled power to the entire enclosure, the
BladeSystem Onboard Administrator report will show that all power supply outputs track each other
fairly closely. This distributes the load evenly, which is particularly important when using three-phase
AC power.
If the user changes the power mode of the enclosure to AC redundant, the BladeSystem Onboard
Administrator ensures that equal numbers of power supplies are available on the A and B sides as
indicated in Figure 20. This logical grouping ensures that when the enclosure is configured with the
three-phase AC input module, all the power supplies on one side will maintain enclosure power if AC
input power is lost on the other side. If the user configures the enclosure power mode to N+1 or not
redundant, the power supplies can be installed in any bay.
Figure 20. HP BladeSystem c7000 power supplies
Connecting to PDUs with AC redundancy to each rack
In an N+N AC redundancy configuration, the total power available equals the amount from the A or
B side, whichever contains fewer power supplies. In this configuration, N power supplies are used to
provide power and the same number are used to provide redundancy, where N can equal 1, 2, or 3.
Any number of power supplies from 1 to N can fail without causing the enclosure to lose power.
When correctly wired with redundant AC line feeds, this configuration will also ensure that a single
AC line feed failure will not cause the enclosure to power off.
Typical power configuration connecting to an uninterruptible power supply (UPS)
In a configuration with N+1 power supply redundancy connecting to a UPS, the total power available
equals the total power available less one power supply. Up to six power supplies can be installed
and one of them is always available to provide redundancy. In the event of a single power supply
failure, the redundant power supply will take over the load of the failed power supply.
Connecting with no power redundancy configured
In a configuration with no power redundancy, the total power available equals the power available
from all installed power supplies. Any power supply or AC line failure will cause the system to power
off if the remaining power supplies are unable to handle the full load.
The BladeSystem Onboard Administrator manages power allocation rules of various components and
can limit overall power capacity for the enclosure. More information on power management is
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