Cooling System Components And Descriptions; T4000 Cooling System Description; Airflow - Juniper T4000 Hardware Manual

CHAPTER 4
Cooling System Components and
Descriptions

T4000 Cooling System Description

Airflow

Copyright © 2018, Juniper Networks, Inc.
T4000 Cooling System Description on page 25
The cooling system components work together to keep all router components within the
acceptable temperature range. The host subsystem monitors the temperature of the
router components. When the router is operating normally, the fans function at normal
speed. If a fan fails or the ambient temperature rises above a threshold, the speed of the
remaining fans is set to full speed. If the ambient maximum temperature specification
is exceeded and the system cannot be adequately cooled, the Routing Engine shuts down
some or all of the hardware components.
In additions to the fans, the front fan trays are equipped with a fan tray controller (FTC)
board. The FTC board is a transition board that distributes the fan-related signals between
the Routing Engine and the fans, and controls the speed as required.
Airflow on page 25
Fan Trays on page 26
Air Filters on page 27
Power Supply Cooling System on page 27
Figure 14 on page 26 shows the airflow through the router.
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