CHAPTER 3
Cooling System and Airflow
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Cooling System and Airflow in an EX4550 Switch on page 35
Cooling System and Airflow in an EX4550 Switch
The cooling system in an EX4550 switch consists of three fan modules and a single fan
in each power supply. EX4550 switches provide back-to-front airflow (air comes in from
the back of the switch) or front-to-back (air exhausts through the back of the switch)
airflow depending on the fan modules and power supplies installed in the switch.
This topic describes:
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Fan Modules on page 35
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Airflow Direction in EX4550 Switches on page 36
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Back-to-Front Airflow on page 37
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Front-to-Back Airflow on page 38
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Do Not Install Components with Different Airflow in the Switch on page 38
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Positioning the Switch on page 38
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Fan Module Status on page 39
Fan Modules
Fan modules for the EX4550 switches are hot-insertable and hot-removable
field-replaceable units (FRUs).
All the EX4550 switchmodels, except the EX4550-32F-S switches are shipped with three
fan modules pre-installed in the rear panel of the switch. EX4550-32F-S switches are
not shipped with pre-installed fan modules; you must order them separately.
Each switch can accommodate three fan modules in the fan module slots on the rear
panel of the switch. The fan module slots are numbered 1 through 3 from left to right.
Each slot has a fan icon next to it.
Figure 21 on page 36 shows a fan module used in an EX4550 switch.
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