Juniper EX4300 Series

Fan Modules
In the EX4300 switches the fan modules are hot-insertable and hot-removable eld-replaceable units
(FRUs).
All the EX4300 switches, except EX4300-24T-S, EX4300-24P-S, EX4300-32F-S, EX4300-48T-S, and
EX4300-48P-S switches are shipped with two fan modules pre-installed in the rear panel of the switch.
EX4300-24T-S, EX4300-24P-S, EX4300-32F-S, EX4300-48T-S, and EX4300-48P-S switches are not
shipped with pre-installed fan modules; you must order them separately. Each switch can accommodate
two fan modules in the fan module slots on the rear panel of the switch. The fan module slots are
numbered 0 and 1 and each slot has a fan icon next to it.
Figure 38 on page 83 shows the fan module used in an EX4300 switch:
Figure 38: Fan Module Used in an EX4300 Switch
You must remove only one fan module at a me for replacement from the rear panel of the chassis. The
switch connues to operate for a limited period of me (30 seconds) during the replacement of the fan
module without thermal shutdown.
NOTE: Both the fan modules must be installed for opmal funconing of the switch.
The fan modules are available in two models that have dierent airow direcons—back-to-front (air
enters through the back of the switch), indicated by label AIR IN (AFI), and front-to-back (air exhausts
through the back of the switch), indicated by label AIR OUT (AFO). Table 27 on page 84 lists the
available fan module models and the direcon of airow in them.
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