Lenovo ThinkSystem NE1072T, Installation Manual

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NE1072T Installation Guide
Rear Panel
The rear panel is composed of the following components.
Fan Modules
For cooling, the rear panel of the NE1072T has five bays for hot-swap fan modules.
Five fan modules are required for redundancy. When five fan modules are used, if
there is a failure of one of the fans, the switch reports the condition, the other fans
continue to run, and the switch continues to operate normally.
You can replace one failed hot-swap fan module while the switch is operating. If a
second fan fails, the switch reports the condition and shuts down to prevent
overheating.
CAUTION:
Be sure to finish the replacement procedure promptly. The switch could overheat
if left without cooling for an extended period.
Compatible fan options are listed in the Lenovo Networking Catalog .
Fan operation and internal temperatures are monitored. If the air temperature
exceeds a desired threshold, the environmental monitor displays warnings.
Note: If a fan fails, the maximum operating temperature drops from +40°C (104°F)
to +35°C (95°F).
Fan airflow can be either front-to-rear or rear-to-front depending on the fan
module:
 Front-to-Rear airflow: air enters the switch through the front panel and exits
through the fans on the rear panel
The following icon is found on the fan module and it depicts that the fan module
has front-to-rear airflow:
 Rear-to-Front airflow: air enters the switch through the fans on the rear panel
and exits through the front panel
The following icon is found on the fan module and it depicts that the fan module
has rear-to-front airflow:
Note: The port side of the switch is considered the Front Panel and the power
supply and fan modules side is considered the Rear Panel.
Fan LEDs
If there is a failure of one or more fans, the front panel Fan LED flashes.
Additional Fan LED indicators are located on the rear panel of the switch, on the
individual fan modules.