LaCie 12big Rack Network
System Overview
User Manual
page 14
1.7.2. Power Supply Output Loom
The Power Supply output loom provides the following outputs:
✦
P1 ATX Motherboard main power connectors (24 pin).
✦
P2 Processor power connector (8 pin)
✦
P3 12V power connector
✦
P4 Peripheral power connector (2 x 4 pin).
✦
P5 PSUI connector (5 pin)
✦
P5 SM bus connector (2 pin)
1.8. Cooling Fans
The Cooling Fans are high speed single rotor axial fans. Ten fans
are housed in a Cooling Cage, located centrally within the enclo-
sure, between the drive bays and the Motherboard, as shown in
Fig.
02
. This ensures maximum airflow through the PSU and minimizes
noise.
Airflow is front to rear with cooling air being drawn across the drives,
through the fans and pressurizing the rear of the enclosure. The
pressurized rear allows the PSU to draw the air that it requires, and
perforations at the rear of the chassis allow cooling airflow over the
Processor heatsinks, memory, motherboard and PCI cards.
The cooling system must be operated with low pressure rear exhaust
installation [Back pressure created by rack doors and obstacles not
to exceed 5 pascals (0.5mm Water gauge)]
The cooling system provides sufficient capacity to ensure that drive
maximum temperatures are not exceeded at 35°C ambient with one
fan failed at sea level.
The Cooling Cage contains ten individual high speed single rotor
axial fans, individually connected to and interfacing with the Enclo-
sure Management PCB. This interface provides power and speed
control to the fans and returns tacho output from each fan
Fig. 08 - Cooling Fan Module