Juniper SRX 5800, Hardware Manual

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SRX5800 Services Gateway Cooling System
The cooling system consists of the following components:
•
Upper fan tray
•
Lower fan tray
•
Air filter tray and air filter
The cooling system components work together to keep all services gateway components within the
acceptable temperature range (see Figure 9 on page 44 , Figure 10 on page 45 , Figure 11 on page 45 ,
Figure 12 on page 45 , and Figure 13 on page 45 ). The services gateway has two fan trays located in the
front of the device that install horizontally above and below the card cage.
Two different types of fan trays are available:
•
The standard capacity fan tray has six fans that operate at 728 cubic feet per minute (CFM) at full speed
and is adequate for services gateways in which standard-capacity power supplies are installed.
•
The high-capacity fan tray has 12 fans that operate at 976 cubic feet per minute (CFM) at full speed and
is required when high-capacity power supplies are installed. When high-capacity fan trays are installed,
you must also install the high-capacity air filter tray.
The fan trays are interchangeable and are hot-insertable and hot-removable.
Figure 9: Airflow Through the Chassis
The host subsystem monitors the temperature of the device components. When the device is operating
normally, the fans function at lower than full speed. If a fan fails or the ambient temperature rises above
a threshold, the speed of the remaining fans is automatically adjusted to keep the temperature within the
acceptable range. If the ambient maximum temperature specification is exceeded and the system cannot
be adequately cooled, the Routing Engine shuts down the system by disabling output power from each
PEM.
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