Power Supply Cooling; Load Sharing - Cisco 7600-SIP-400 - SPA Interface Processor 400 Installation Manual

Chapter 1 Product Overview
Figure 1-33

Power Supply Cooling

Each power supply has a minimum one built-in fan. On the Cisco 7603 router, Cisco 7604 router, and
the Cisco 7606 router, air enters from the right of the fan and exits through the left. On the Cisco 7609
router, the Cisco 7609-S, and the Cisco 7613 router, air enters the front of the fan (power-input end) and
exits through the back; an air dam keeps the airflow separate from the rest of the chassis, which is cooled
by the system fan assembly.
The Cisco 7603 router power supplies are self cooling to 77°F (25°C), but require additional airflow
provided by the system fan module to operate over the full temperature range. The Cisco 7604 router,
Cisco 7606 router, Cisco 7609 router, and Cisco 7613 router power supplies are completely self-cooling.

Load Sharing

When you install and turn on two power supplies, each power supply concurrently provides
approximately half of the required power to the system. If one power supply fails, the second power
supply immediately assumes full power to maintain uninterrupted system operation. Installing the
second power supply enables load sharing and fault tolerance automatically; no software configuration
is required.
For proper load-sharing operation in a redundant power supply configuration, you must install two
Note
modules in the chassis. If you fail to install two modules, you might receive spurious OUTPUT FAIL
indications on the power supply.
For information about the power management feature and individual module power consumption, refer
to the Cisco 7600 Series Router Supervisor Engine and Route Switch Processor Guide.
OL-4503-26
6000 W DC-Input Power Supply
CI SC O SY
ST EM S, IN
C
1
2
3
INP UT
4
OK
FA N
OK OU TP UT
FA IL
Cisco 7600 Series Router Components
Cisco 7600 Series Router Installation Guide
1-31