Oracle X5-4 Service Manual page 26

Server Subsystems Overview
Power Supply Cooling Area
The power supply area uses fans at the back of the power supplies to draw cool air in past the
drives, through power supplies, and out the back.
Motherboard Cooling Area
The motherboard area is divided into three zones where six 92-mm high-performance fans
pull cool air in from the front of the server, move it across the motherboard, memory risers,
processors, and I/O cards, and exhausts warm air out the back of the server.
The six fan modules are arranged in two rows allowing for a pair of redundant stacked fans for
each of the three motherboard zones. If one of the fan modules fails, the other fan module in the
pair has sufficient power to cool the zone until the failed fan can be replaced. However, if both
fan modules in a pair fail, Oracle ILOM will power off the system to prevent thermal damage.
Pressure Areas
The power supply and motherboard cooling areas have separate air pressures. The pressures are
maintained by a plastic divider that, combined with the top cover, creates a seal between the two
areas. It is important to maintain this seal because separate pressurizations for each area is the
key to maintaining the integrity of the cooling system and the health of the server.
Cooling Zones and Temperature Sensors
The two cooling areas are divided into four zones, one zone for the power supply area and three
zones for the motherboard area. Dividing the cooling into zones allows for greater use of system
resources, since each zone can operate independently at its highest efficiency. The zones are
designated from left to right (from the front of the server) as: zone 0, zone 1, zone 2, and zone 3
(power supply area). Temperature monitoring of each zone is accomplished using motherboard-
mounted temperature sensors.
The following illustration shows the cooling zones and the approximate location of the
temperature sensors. The accompanying legend table provides sensor NAC names and sensor
motherboard designations:
26 Oracle Server X5-4 Service Manual • December 2015