Cisco 3800 Series - Manual (Page 57)

Power Connections
27
Connecting Cables to Cisco 3800 Series Routers
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Figure 19 Source A and Source B Wired with Opposite-Polarity Grounds
Connecting Routers to Backup Power
The Cisco 3845 router accommodates two hot-swappable power supplies in bays at the front of the
router. A single power supply meets router requirements. The second power supply provides
redundancy, load sharing, and increased router availability. Either power supply can be removed without
affecting router operation. Any combination of two power supplies is permitted.
For instructions for installing a second power supply in a Cisco 3845 router, see the “ Installing and
Upgrading Internal Components in Cisco 3800 Series Routers ” section.
The Cisco 3825 router has one internal power supply and provides a connector to an optional
Cisco Redundant Power System (RPS) external backup source.
Figure 20 and Figure 21 illustrate this
connection. Use a flat-blade screwdriver to pry off the door over the RPS connector before connecting
the cable. See the
Cisco RPS-675 Hardware Installation Guide for complete RPS power connection
instructions.
Caution Before connecting the RPS to the router, make sure that either the RPS is in standby mode or the RPS
AC power is disconnected. Connecting the RPS to AC power automatically places the RPS in
active mode.
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