SRX5800 Services Gateway Cooling System Description

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 1, Figure 2, Figure 4, and Figure 5). The services gateway has two fan trays located in the front of the device that install horizontally above and below the card cage. The fan trays are interchangeable and are hot-insertable and hot-removable.

Figure 1: 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.

There is a single air intake in the front of the services gateway. Air is pushed up through an air filter, through the card cage, and then through the upper fan tray where it combines in a common exhaust plenum and is exhausted out the upper rear of the system.

Two different types of fan tray are available:

• The standard capacity fan tray has six fans and is adequate for services gateways in which standard-capacity power supplies are installed.
• The high-capacity fan tray has 12 fans 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.

Figure 2: Standard-Capacity Fan Tray (Same Upper and Lower)

Figure 3: High-Capacity Fan Tray (Same Upper and Lower)

Figure 4: Air Filter

Figure 5: Standard-Capacity Air Filter Tray

Figure 6: High-Capacity Air Filter Tray