Cooling System Components And Descriptions; M120 Cooling System Description - Juniper M120 Hardware Manual

CHAPTER 4
Cooling System Components and
Descriptions

M120 Cooling System Description

Copyright © 2018, Juniper Networks, Inc.
M120 Cooling System Description on page 19
The cooling system consists of the following components:
Two front fan trays
Two rear fan trays
Front air filter
The cooling system components work together to keep all router components within the
acceptable temperature range (see
Figure 9 on page 20). The router cooling system comprises two front and two rear fan
trays (see Figure 1 on page 8
install horizontally above and below the front and rear card cages. Each fan tray contains
eight fans. The two front fan trays are interchangeable, the two rear fan trays are
interchangeable, but the front and rear fan trays are not interchangeable. The fan trays
are hot-insertable and hot-removable. The front fan trays cool the components installed
in the front card cage (the FPCs, CFPCs, PICs, and craft interface). The rear fan trays cool
the components installed in the rear card cage (the Routing Engines, CBs, power supplies,
and FEBs). Figure 7 on page 20
An air filter in the front in the chassis located beneath the lower fan tray helps keep dust
and other particles from entering the cooling system. To function properly, the entire
cooling system requires an unobstructed airflow and proper clearance around the site,
as described in "M120 Clearance Requirements for Airflow and Hardware Maintenance"
on page 85.
Figure 7 on page 20,
and Figure 2 on page 8). Both the front and rear fan trays
shows the airflow through the router.
Figure 8 on page 20, and
19