Compaq ProLiant BL e-Class System Overview and Planning

Compaq ProLiant BL e-Class System Overview and Planning 21
AC Source
An AC source is AC power delivered via an AC wall outlet, main circuit breaker or a building’s
power infrastructure. This term also loosely describes AC power delivered to a power supply or
PDU.
AC Source Failure
The AC source supplying power to a component has failed.
AC Source Redundancy
An AC source redundancy is a power configuration that enables an enclosure (or rack of
enclosures) to survive the failure of an AC source by re-distributing the load to an
alternate AC source.
Figure 9. AC source full redundancy
Figure 9 shows a configuration that can survive a power supply failure, PDU failure, and even a
single AC source failure.
Note: AC source redundancy implies the remaining AC source and PDU(s) have sufficient
capacity to safely handle the re-distributed power load.
Figure 10. Dual AC PDU and power supply redundancy, single source of failure = PDU
Figure 10 shows a dual-AC PDU configuration that can survive a power supply failure, and even
a single AC source failure.
Note: The dual-AC PDU is still a potential single source of failure.