Cooling System And Airflow; Cooling System And Airflow In An Ex4300 Switch; Fan Modules - Juniper EX4300 Hardware Manual

CHAPTER 3

Cooling System and Airflow

Cooling System and Airflow in an EX4300 Switch

Fan Modules

Copyright © 2017, Juniper Networks, Inc.
Cooling System and Airflow in an EX4300 Switch on page 43
The cooling system in an EX4300 switch consists of two fan modules and a single fan
in each power supply. EX4300 switches provide back-to-front airflow (air enters through
the back of the switch), indicated by the label
through the back of the switch), indicated by the label
the fan modules and power supplies installed in the switch.
This topic describes:
Fan Modules on page 43
Airflow Direction in EX4300 Switch Models on page 44
Front-to-Back Airflow on page 45
Back-to-Front Airflow on page 46
Do Not Mix AIR IN (AFI) and AIR OUT (AFO) Components in the Switch on page 47
Positioning the Switch on page 47
Fan Module Status on page 48
In the EX4300 switches the fan modules are hot-insertable and hot-removable
field-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 27 on page 44 shows the fan module used in an EX4300 switch:
AIR IN (AFI) , or front-to-back (air exhausts
-depending on
AIR OUT (AFO)
43