Cisco cBR Series Hardware Installation Manual page 47

What is a Cisco cBR Series Converged Broadband Router
Fan Module
The Cisco cBR-8 router has multiple modular Fan Modules installed in the rear to supply cooling air and have
five Fan Module bays in the rear of the chassis. The bays are numbered from P10 to P14.
Figure 23: Fan Module
1
2
3
4
Each Fan Module has two fans and a control board. The fans in each Fan Module are synchronized and operate
at variable speeds as set by the Supervisor. Fan speeds are determined based on ambient temperature and
pressure. When the chassis boots up, the operating speed of the fans is set to the default number of revolutions
per minute (RPM) in unsupervised mode. The multi Fan Module cooling architecture permits only one fan
failure at any time in any given Fan Module during normal operational conditions. All the remaining fans are
capable of changing to full speed operation to compensate for the failed fan or module.
Each fan bay has one hinged rear door and one sliding side door which close when a Fan Module is removed
for replacement. This prevents re-circulation of air which could lead to the system overheating. The multi
cooling architecture permits only one fan failure at any time in any given during normal operational conditions.
Product Identifier (PID)
Front Grille Panel
Front Fan
LEDs
5 Control Panel
6 Rear Fan
7 PID label
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Cisco Converged Broadband Routers Hardware Installation Guide
Fan Module
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