Fan Modules - Juniper ACX5448-D Hardware Manual

CAUTION:
chassis.

Fan Modules

The fan modules in ACX5400 routers are hot-insertable and hot-removable field-replaceable units (FRUs).
The fan modules are installed in the fan module slots on the rear of the router. The ACX5400 routers
support six fan modules numbered 0 through 5 from left to right, with each fan module slot having a fan
icon next to it.
The ACX5400 routers are available with either front-to-back airflow (airflow out, ports-to-FRUs, or AFO),
or back-to-front airflow (airflow in, FRUs-to-ports, or AFI). In AFO models, the air is pulled through the
front of the chassis toward the fan modules, from where it is exhausted out of the chassis. In AFI models,
the air is pulled through the fan modules and toward the front of the chassis, from where it is exhausted
out of the chassis. The fan modules and the power modules are available in both AFO and AFI models.
Figure 32 on page 48 shows an ACX5400 fan module.
Figure 32: Fan Module Used in ACX5400 Routers
You remove and replace a fan module from the FRU end of the chassis. The router continues to operate
for a limited period of time (30 seconds) during the replacement of the fan module without thermal
shutdown.
NOTE: All fan modules must be installed for optimal operation of the router.
Table 16 on page 49 lists the available fan modules and the direction of airflow in them.
Do not mix fan modules and PSMs with AFO and AFI labels in the same
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