Juniper EX3300 Series

In back-to-front airflow models, the air intake is located on the rear of the chassis. Cool
air is pulled into the chassis and pushed toward the front of the chassis. Hot air exhausts
from the front of the chassis. See Figure 11 on page 23.
Figure 11: Back-to-Front Airflow Through the EX3300 Switch Chassis
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Chassis rear
Chassis front
Fan
Fan
Air exhaust
Fan air
intake
Air exhaust
Air intake
Under normal operating conditions, the fans operate at moderate speeds for minimal
noise. Temperature sensors in the chassis monitor the temperature within the chassis.
If any fan fails or if the temperature inside the chassis rises above the threshold, the
switch raises an alarm and all functioning fans operate at a higher speed than normal.
If the temperature inside the chassis rises above the threshold, the switch shuts down
automatically.
Related
Documentation
• Rear Panel of an EX3300 Switch on page 7
• Chassis Status LEDs in EX3300 Switches on page 16
• Understanding Alarm Types and Severity Levels on EX Series Switches
• Prevention of Electrostatic Discharge Damage on page 158
23Copyright © 2011, Juniper Networks, Inc.
Chapter 2: Component Descriptions