23
PSU & Cooling Module
The two redundant, hot-swappable PSUs have an extraction handle
(1)
, cooling
module
(2)
, latch
(3)
, PSU status LED
(4)
and a power socket
(5)
.
The cooling modules can operate at three rotation speed settings. Under normal
operating conditions, the cooling fans run at the low speed. Under the following
conditions, cooling fans raise their rotation speed to increase the airflow:
Component failure: if a cooling module, PSU, or a temperature sensor
fails.
Elevated temperature: if the temperature breaches the upper threshold
set for any of the interior temperature sensors.
During the system initialization stage, the cooling fans operate at high
speed and return to low speed once the initialization process has
completed and no erroneous condition detected.
NOTE
There are two upper temperature thresholds: one for event notification and the other
for triggering higher fan rotation speed. The preset-value for event notification can be
changed using the firmware-embedded configuration utility, while the fan speed
trigger cannot be changed. Refer to the Firmware Operation Manual for details.
