Troubleshooting The Cooling System; Figure 40: Airflow Through The Chassis - Juniper SRX 5600 Hardware Manual

SRX 5600 Services Gateway Hardware Guide

Troubleshooting the Cooling System

The services gateway cooling system is a fan tray and an air filter, both of which are
located vertically in the rear of the chassis (see Figure 1 on page 6). The fan tray
contains six fans. The fan tray provides cooling to the components installed in the
device. Figure 40 on page 94 shows the airflow through the device.
An air filter installed in the rear of the chassis helps keep dust and other particles
from entering the cooling system. To function properly, the entire cooling system
requires an unobstructed airflow and proper clearance around the site, as described
in "Preparing the Site for Services Gateway Installation" on page 37.

Figure 40: Airflow Through the Chassis

During normal operation, the fans in the fan tray function at less than full speed.
The SCB constantly monitors the temperatures detected by sensors and device
components, adjusting the speed of the fans as necessary. If the device temperature
exceeds the acceptable maximum, the SCB turns off the power supplies. The following
conditions automatically cause the fans to run at full speed and also trigger the
indicated alarm:
To troubleshoot the fans, follow these guidelines:
94
Troubleshooting the Cooling System
A fan fails (red alarm).
The fan tray is removed (yellow alarm and red alarm).
The device temperature exceeds the "temperature warm" threshold (yellow
alarm).
The temperature of the device exceeds the maximum ("temperature hot")
threshold (red alarm and automatic shutdown of the power supplies).
If the red alarm LED on the craft interface lights, use the CLI to get information
about the source of an alarm condition:
information about alarms, see "Alarm LEDs and Alarm Cutoff/Lamp Test Button"
on page 24.
If the CLI output lists only one fan failure, and the other fans are functioning
normally, the fan is most likely faulty and you need to replace the fan tray, as
described in "Replacing the Fan Tray" on page 104.
user@host> show chassis alarms . For