Juniper TCX1000-RDM20, Hardware Manual

Page: 31 / 206

CHAPTER 3
Cooling System Components and
Descriptions
• TCX1000-RDM20 Cooling System Description on page 17
TCX1000-RDM20 Cooling System Description
The cooling system in a TCX1000-RDM20 consists of two fan modules installed in the
field-replaceable unit (FRU) panel and each power supply has a dual rotor
counter-rotating fan in them.
In the TCX1000-RDM20’s cooling system, cool air enters through the vents in the front
panel and hot air exhausts through the fans in the FRU panel. This type of airflow is known
as
airflow out or front-to-back airflow. When installed, the chassis must be positioned
so that the FRUs are next to the hot air exhaust.
NOTE: Under normal operating conditions, the fan modules operate at a
moderate speed. Temperature sensors in the chassis monitor the temperature
within the chassis. The system raises an alarm if a fan module fails or if the
ambient temperature inside the chassis rises above the acceptable range.
• Fan Modules on page 17
• Airflow Through the Chassis on page 18
Fan Modules
The fan modules in a TCX1000-RDM20 are hot-removable and hot-pluggable FRUs.
These fan modules can be hot-swapped—you do not need to power off the
TCX1000-RDM20 or disrupt the TCX1000-RDM20 function to replace a fan module. The
TCX1000-RDM20 continues to operate for a limited period of time (two minutes) during
the replacement of the fan module without thermal shutdowns. Fan module slots are
numbered
0
through
1
from left to right when viewing chassis from the FRU panel side
(see Figure 8 on page 18 ). Figure 9 on page 18 shows the fan module for the
TCX1000-RDM20.
17 Copyright © 2019, Juniper Networks, Inc.