Fan Trays; Figure 15: Airflow Through The Chassis - Juniper T640 Hardware Manual

T640 Core Router Hardware Guide

Fan Trays

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Figure 15: Airflow Through the Chassis

NOTE: The standard fan trays and quiet fan trays are not interchangeable
with each other. All fans in the chassis must be either standard fan trays or
quiet fan trays.
The cooling system contains the following fan trays:
One rear fan tray cools the components installed in the rear card cage (the Routing
Engines, control boards, SCGs, and the SIBs). The T640 router supports the following
types of rear fan trays:
The standard rear fan tray with five blowers (EOL) is supported by Junos OS 5.3 and
later. It has no label and is not interchangeable with the standard front fan trays.
The standard rear fan tray with eight fans is supported by Junos OS 8.5 and later. It
has no label and is not interchangeable with the standard front fan trays.
The quiet rear fan tray, labeled
OS 11.1 and later, contains eight fans and is not interchangeable with the quiet front
fan trays.
One upper front fan tray and one lower front fan tray that cool the components installed
in the front card cage (the FPCs, PICs, CIP, and midplane). The T640 router supports
the following front fan trays:
The upper and lower standard front fan trays, each of which contain six fans and
have no labels. Both standard fan trays are interchangeable with each other.
Each quiet front fan tray contains four fans, as indicated by the four fan icons on the
faceplate.
REAR FANTRAY FAN-R-S and supported by Junos
Copyright © 2017, Juniper Networks, Inc.