Juniper EX4100 Hardware Manual page 65

Table 11: Airflow Direction in EX4100 and EX4100-F Switch Models
Model Number
•
EX4100-F-24P
•
EX4100-F-48P
EX4100-48T-AFI
CAUTION: Do not mix:
• Power supplies with different airflow directions in the same chassis.
• Fan modules with different airflow directions in the same chassis.
• Power supplies and fan modules with different airflow directions in the same chassis.
If you install power supplies or fan modules with different airflow directions, Junos OS
raises an alarm.
Under normal operating conditions, the fan modules operate at a moderate speed.
Temperature sensors in the chassis monitor the temperature within the chassis.
If a fan module fails, or if the ambient temperature inside the chassis rises above the
acceptable range, Junos OS raises an alarm. If the temperature inside the chassis rises
above the threshold temperature, the system shuts down automatically.
(Continued)
Fan Modules and Power
Supply
Two built-in fans with AFO
cooling.
The switch ships with two
fan modules and an AC
power supply, each with a
label AIR IN and a Juniper
Azure Blue handle.
Direction of Airflow
Front-to-back—cold air to
cool the chassis enters
through the vents on the
front panel of the chassis,
and hot air exits through
the vents on the rear panel
of the chassis.
Back-to-front—cold air to
cool the chassis enters
through the vents on the
rear panel of the chassis,
and hot air exits through
the vents on the front panel
of the chassis.
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