MX240 Cooling System Description

The cooling system consists of the following components:

• Fan tray
• Air filter

The cooling system components work together to keep all router components within the acceptable temperature range (see Figure 1, Figure 2, and Figure 3). The router has one fan tray and one air filter that install vertically in the rear of the router. The fan tray contains three fans. The MX Series high-capacity fan trays satisfy cooling requirements for high-density DPCs and MPCs, and must be upgraded for proper cooling.

The air intake to cool the chassis is located on the side of the chassis next to the air filter. Air is pulled through the chassis toward the fan tray, where it is exhausted out the side of the system. The air intake to cool the power supplies is located in the front of the router above the craft interface. The exhaust for the power supplies is located on the rear bulkhead power supplies.

Figure 1: Airflow Through Chassis

The host subsystem monitors the temperature of the router components. When the router 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 power supply.

Figure 2: Fan Tray

Figure 3: Air Filter