IBM p5 590 System Handbook page 153

Power subsystem
The primary system frame always incorporates two bulk power assemblies for
redundancy. These provide 350 VDC power for devices located in those frames
and associated nonpowered Expansion Racks. These bulk power assemblies are
mounted in front and rear positions and occupy the top 8U of the frame. To help
provide optimum system availability, these bulk power assemblies should be
powered from separate power sources with separate line cords.
The following list summarizes considerations specific to the power sub-system:
Three DC Power Converters (FC 7809) are always required for miscellaneous
CEC components and the first 16-way processor book.
Three additional DC Power Converters must be added for each additional
16-way processor book.
The base CEC contains four cooling fans. Cooling Group FC 7807 is required
in following condition:
– p5-590 server with two 16-way processor modules installed.
– p5-595 with one or more 1.9 GHz POWER5 processor books (FC 7813)
– p5-595 with two or more 1.65 GHz POWER5 processor books (FC 7988)
Power cable groups are used to connect the DC Power Converters to the bulk
power assembly.
– FC 7821 provides power for the CEC and four cooling fans
– FC 7822 provides power for the first processor book
– FC 7823 provides power for the second processor book
– FC 7824 provides power for the third processor book of p5-595
– FC 7825 provides power for the fourth processor book of p5-595
– FC 7826 provides power for Cooling Group FC 7807
Powered Expansion Rack (FC 5792)
Available in p5-595 for large system configurations that require more power and
space than is available from the primary system frame. It provides the same
redundant power subsystem available in the primary frame.
Unpowered Expansion Rack (FC 8691)
Available for both p5-590 and p5-595 if additional 24-inch frame space is
required. To install the Expansion Rack feature, the side cover of the system
frame is removed, the Expansion Rack is bolted to the side, and the side cover is
placed on the exposed side of the Expansion Rack. The Unpowered Expansion
Rack can get power from either the system frame or an attached Powered
Expansion Rack depending on the configuration.
Chapter 5. Configuration tools and rules
131