T320 Router and T640 Routing Node Cooling Systems
The T320 cooling system consists of the following components:
- Two front fan trays—The front fan trays each contain six fans and are interchangeable. The fan trays in the front of the chassis, each with six fans, cool the components installed in the FPC card cage (the FPCs, PICs, CIP, and midplane).
- Rear fan tray—The rear fan tray contains five fans and is not interchangeable with the front trays. It cools the components installed in the rear card cage (the Routing Engines, Control Boards, PCGs, and SIBs).
- Front and rear air filter—Air filters for both the front and rear fan trays help keep dust and other particles from entering the cooling system.
- Power supply fans—The power supplies each have a fan that cools that power supply.
During normal operation, the fans in each fan tray function at less than full capacity. Temperature sensors on the midplane and the host subsystem control the speed of the fans. A fan failure triggers the red alarm LED on the craft interface. If the temperature passes a certain threshold, the JUNOS software turns off the power supplies.
Figure 117 shows the T320 router cooling system components.
Figure 118 shows the T320 router airflow.
Figure 119 shows the T640 routing node airflow.
Figure 120 shows the T640 routing node cooling system components.
