Sun Fire V445 Server Administration Guide - SCN Research

Power Supply Configuration Rules
■
■
Hot-swap a power supply only when there are at least two other power supplies
online and working properly.
Good practice is to connect the four power supplies to two separate AC circuits,
two supplies per circuit, which enables the system to remain operational if one of
the AC circuits fails. Consult your local electrical codes for any additional
requirements.
About the System Fan Trays
The system is equipped with six fan trays organized into three redundant pairs. One
redundant pair is for cooling the disk drives. The other two redundant pairs are for
cooling the CPU/memory modules, memory DIMMs, I/O subsystem, and provide
front-to-rear cooling of the system. Not all fans must be present to provide adequate
cooling – only one fan per redundant pair must be present.
Note – All system cooling is provided by the fan trays – power supply fans do not
provide system cooling.
The fans in the system plug directly into the motherboard. Each fan is mounted on
its own tray and is individually hot-swappable. If either fan in a pair fails the
remaining fan is adequate to keep its portion of the system cool. The presence and
health of the fans are indicated through six bicolor indicators located on the SAS
backplane.
Open the fan tray doors on the top cover of the server to access the system fans.
Power supplies are cooled separately, each power supply with its own internal fan.
Caution – Fan trays contain sharp moving parts. Use extreme caution when
servicing fan trays and blowers.
FIGURE 4-7 shows all six system fan trays and their corresponding indicators. For
each fan in the system, the environmental monitoring subsystem monitors fan speed
in revolutions per minute.
86 Sun Fire V445 Server Administration Guide • August 2006