Cooling System And Airflow In The Junos Pulse Gateway Mag6610, Mag6611; Component Descriptions - Juniper Junos Pulse MAG2600 Hardware Manual

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Cooling System and Airflow in the Junos Pulse Gateway MAG6610, MAG6611

Copyright © 2014, Juniper Networks, Inc.
Each AC power supply has an ejector lever that holds the power supply in place. The
ejector lever locks into the corresponding hole in the chassis on the left side of the AC
appliance inlet.
Each AC power supply comes with a power cord retainer that holds the power cord in
place.
Each power supply has its own fan and is cooled by its own internal cooling system. The
airflow for a power supply is from the front of the power supply to the back.
Installing an AC Power Supply in the MAG6610 or MAG6611 on page 47
Removing the MAG6610 and MAG6611 AC Power Supply on page 89
Monitoring the Junos Pulse Gateway Components Using LEDs on page 99
The cooling system in a Junos Pulse Gateway MAG6610 or MAG6611 consists of one or
more fan trays. Each fan tray contains two fans. All fans and fan trays are a hot-insertable
and hot-removable field-replaceable unit (FRU).
You remove and replace the fan tray from the rear of the chassis.
The Junos Pulse Gateway continues to operate for a limited time (15 seconds) during
the replacement of the fan tray without thermal shutdown. The fan tray provides
front-to-back airflow. The air intake to cool the chassis is located on the front of the
chassis. Air is pulled into the chassis and pushed toward the fan tray. Hot air exhausts
from the rear of the chassis.
Temperature sensors in the chassis monitor the temperature in the chassis. The fan tray
used in the Junos Pulse Gateway comes with load-sharing redundancy that can tolerate
a single fan failure at room temperature (below 113° F/45° C) to continue to provide
sufficient cooling.
Under normal operating conditions, the fans in the fan tray run at less than full speed. If
a fan fails or the ambient temperature rises above the threshold 113 °F (45 °C), the speed
of the remaining fans is automatically adjusted to keep the temperature within the
acceptable range, 32 °F (0 °C) through 113 °F (45 °C).
The system raises an alarm if the fan fails or if the ambient temperature inside the chassis
rises above the acceptable range. If the temperature inside the chassis rises above the
threshold temperature, the system shuts down automatically.
You can check the status of fans and the chassis temperature from the J-Web interface
if you have a chassis management card (CMC) installed.
You cannot replace a single fan. If one or more fans fail, you must replace the entire fan
tray.
Chapter 3: Component Descriptions
19