Juniper MX480, Руководство по оборудованию

Страница: 42 / 420

The cooling system components work together to keep all router components within the
acceptable temperature range (see
Figure 8 on page 42 , Figure 9 on page 43 , and
Figure 10 on page 43 ). The router has one fan tray and one air filter that install vertically
in the rear of the router. The fan tray contains six 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 8: Airflow Through the 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.
Copyright © 2019, Juniper Networks, Inc. 42
MX480 Universal Routing Platform Hardware Guide