Power Management Overview; Understanding Power Management Modes - Cisco WS-C2948G-GE-TX Configuration Manual

Understanding How Power Management Works on the Catalyst 4500 Series Switches

Power Management Overview

Catalyst 4500 series switches support the following power supplies:
•
•
For more information on available wattage for the power supplies, see
Do not use the 1400 W DC power supply with any other power supply, even for a hot swap or other
Caution
short-term emergency, because you can seriously damage your switch.
If you use power supplies with different types or wattages in your switch, the switch uses the power
Note
supply in power supply bay 1 (PS1) and ignores the power supply in power supply bay 2 (PS2). If you
use different wattages, your switch will not have power redundancy.

Understanding Power Management Modes

Catalyst 4500 series switches support these two power management modes:
•
•
Your switch hardware configuration dictates which power supply or supplies you should use. For
example, if your switch configuration requires more power than a single power supply provides, use the
combined mode. In combined mode, however, the switch has no power redundancy.
See
Note
supplies in either combined or redundant mode for the Catalyst 4500 series switches. See
page 28-9
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide
28-2
Fixed wattage—These power supplies always deliver a fixed amount of inline and system power:
– 1000 W AC
– 2800 W AC
Variable wattage—These power supplies automatically adjust the wattage to accommodate inline
and system power requirements:
– 1300 W AC
1400 W DC
–
Redundant mode—Uses one power supply as a primary power supply and the second power supply
as a backup. If the primary power supply fails, the second power supply supports the switch without
disrupting the network. Both power supplies must have the same wattage. A single power supply
must have enough power to support the switch configuration. By default, the power supplies in the
Catalyst 4500 series switch are set to redundant mode.
Combined mode—Uses the power from all installed power supplies to support the power
requirements of the switch configuration. Combined mode has no power redundancy; if a power
supply fails, one or more modules might shut down. Combined mode requires that your switch has
two power supplies. The 1400 W DC power supply does not support combined mode.
Table 28-1 on page 28-4 for a list of the maximum available power that is provided by the power
for the power requirements of the Catalyst 4500 series switching modules.
Chapter 28 Power Management
Table 28-1 on page 28-4.
Table 28-2 on
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