28-8
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide
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Release 8.2GLX
78-15908-01
Chapter 28 Power Management
Understanding How Power Management Works on the Catalyst 4006 Switch
During the evaluation cycle, the modules are removed and reinserted. The switch reactivates only the
modules that it is able to support with the limited power available and leaves the remaining modules in
reset mode. The supervisor engine always remains enabled. Modules that are placed in reset mode still
consume some power. If the chassis module combination and the modules in reset mode still require
more power than is available, the timer starts again, and additional modules are placed into reset mode
until the power usage is stable.
If the power requirement of the active modules and the modules in reset mode do not exceed the available
power, the switch is stable and no more evaluation cycles are run, until something again causes
insufficient power usage. One or two cycles are required to stabilize the switch. If you configure the
chassis correctly, the switch does not enter the evaluation cycle.
Note
If all three power supplies are installed in your Catalyst 4006 switch and you set 1+1 redundancy mode
but later add additional modules that exceed the power available, the timer starts again. The switch may
require several evaluation cycles to stabilize the system.You can either remove the extra modules or
change the power budget to 2+1 redundancy mode. If you change to 2+1 redundancy mode, each module
in reset mode is brought up one at a time to an operational state.
If you use a 400 W power supply and a 650 W power supply in your switch, the switch acts as if there
were two 400 W power supplies.
If you have one 400 W power supply and one 650 W power supply in 1+1 redundancy mode, and a
second 650 W power supply is set as the backup, the switch acts as if there were a total of 400 W. If the
400 W power supply fails, the backup 650 W power supply comes into service; however, the switch still
has only 400 W available. You must remove the failed 400 W power supply so that the switch can use
the available 650 W.
The following configuration requires a minimum of 395 W:
•
WS-X4013 supervisor engine—110 W
•
Four WS-X4148-RJ modules—65 W each (260 W total—the optimized module configuration)
•
Fan tray—25 W
The following configuration requires more power than a single 400 W power supply can provide. It
requires 445 W and cannot be used in 1+1 redundancy mode for a 400 W power supply. A single 650 W
power supply provides enough power for 1+1 redundancy mode for this configuration.
•
WS-X4013 supervisor engine—110 W
•
Two WS-X4148-RJ modules in slots 2 and 3—65 W each (130 W total)
•
Two WS-X4448-GB-LX modules in slots 4 and 5—90 W each (180 W total)
•
Fan tray—25 W
The following configuration requires more power than either a single 400 W or 650 W power supply can
provide. It requires 735 W and cannot be used in 1+1 redundancy mode for either a 400 W or 650 W
power supply.
•
WS-X4013 supervisor engine—110 W
•
Five 48-port 100BASE-FX modules in slots 2 through 6—120 W each (600 W total)
•
Fan tray—25 W