B-24 SPARC Enterprise M8000/M9000 Servers Service Manual • June 2010
B.16 Power Supply Unit
The power supply unit (PSU) receives AC 200 to 240 V, and supplies each unit of the
SPARC Enterprise with DC48 V and 12 VL. When all CMUs and IOUs are mounted
without the dual power feed option, nine units for the M8000, 15 units for the M9000
(base cabinet only) and 30 units for the M9000 (with expansion cabinet) will be
mounted. The number of mounted units also vary with the system configuration.
The PSU is shown in
FIGURE B-18.
FIGURE B-18 Power Supply Unit (PSU)
The PSU has the following characteristics.
■ Because PSUs are normally operating in redundancy, active maintenance of a
failed PSU during system operation is possible.
■ The internal power factor correction (PFC) circuit secures the stable output and
suppresses the harmonic current that adversely affects the environment.
■ The current balancing function enables the concurrent operation of a large
number of PSUs, allowing the redundant configurations.
■ The PSU has a label bearing the printed component number and manufacture's
serial number.