Air exhaust plenum
7
Air inlet plenum
2
Fan trays (rear)
8
Air filter
3
Rear upper and lower card cages
9
Front upper and lower card cages
4
Rear side of the FCC
10
Air flow through PMs
5
The airflow volumes for a fully loaded Cisco NCS 6000 FCC are as follows:
•
Chassis airflow: Up to 1980 cubic feet (56,6000 liters) per minute
•
DC power system airflow: Up to 120 cubic feet (3400 liters) per minute
•
AC power system airflow: Up to 88 cubic feet (2500 liters) per minute
About the Fan Trays
The Cisco NCS 6000 FCC has two fan trays located directly above the upper cable management bracket on
the rear of the FCC (
Figure 2: Rear View of the Cisco NCS 6000 FCC
When there is one or more fan failures, the system monitors the temperature sensors mounted on the critical
components within the various boards and increases fan throughput to hold temperatures below their critical
threshold. The system does this monitoring even when all the fans are operating correctly (so that it protects
the components if the air intake is blocked for example). If temperatures exceed the critical threshold, the
associated cards are shut down to avoid permanent damage.
If either fan tray is removed from the FCC, the other fan tray will immediately spin up to maximum speed to
provide sufficient cooling performance. Although the system can operate indefinitely at full capacity with
just one operational fan tray up to an ambient room temperature of 40°C (104°F) without overheating, there
is no longer any redundancy offered, so immediate replacement of the missing fan tray is advised.
When both fan trays are removed, a critical alarm is generated, along with a syslog message warning you to
install a fan tray or the entire FCC will shut down in 45 seconds.
The upper and lower fan trays are interchangeable so the fan tray installation is the same.
Note
Fan Tray LEDs
The green/yellow LED lights when the fan tray is inserted into the fan tray slot. The following table describes
the fan tray LEDs and their meanings.
Table 12: NCS 6000 FCC Fan Tray LEDs
Description
LED Color
The fan tray is operating normally.
Green
The fan tray has one or more errors detected.
Yellow
Cisco Network Convergence System 6000 Fabric Card Chassis Hardware Installation Guide
111
Removing and Replacing Chassis Components
About the Fan Trays and Air Filter