7-5
Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter7 Environmental Moni toring and Power Management
Power Management
–
1400 W DC Service Provider—Uses up to three lines (12.5 A, 15 A, 15 A) of DC input and
delivers varying amounts of system power ranging from 400 W to 1400 W depending o n the
lines powered. See “Special Considerations for the 1400 W DC SP Triple Input Power Supply”
section on page 7-14 for more information. (PoE not supported)
–
4200 W AC—Supports varying amounts of system power and PoE depending on the number of
inputs powered and input voltage.
Note All Catalyst 4500 series switch AC-input power supplies require single-phase source AC. The source AC
can be out of phase between multiple power supplies or multiple AC-power plugs on the same power
supply because all AC power supply inputs are isolated. Each chassis power supply should have its own
dedicated branch circuit: 20A for North America and circuits sized to local and national codes for
International locations.
When you insert power supplies in your switch, use power supplies that are of the same wattage.
Multi-input power supplies such as 1400 W DC triple-input and 4200 W AC have additional restrictions.
Read the sections on special considerations for these power supplies. If you mix power supplies, the
switch will use the one it recognizes first and ignore the other power supply. The power supply status
displays as err-disable and the summary displays as all zeros (0) for wattage values in the output for the
show power command.
The following example shows the output for the show power command for mixed power supplies:
Switch# show power
Power Fan Inline
Supply Model No Type Status Sensor Status
------ ---------------- --------- ----------- ------ ------
PS1 PWR-C45-2800AC AC 2800W good good good
PS2 PWR-C45-1000AC AC 1000W err-disable good n.a.
*** Power Supplies of different type have been detected***
Power supplies needed by system :1
Power supplies currently available :1
Power Summary Maximum
(in Watts) Used Available
---------------------- ---- ---------
System Power (12V) 328 1360
Inline Power (-50V) 0 1400
Backplane Power (3.3V) 10 40
---------------------- ----
Total Used 338 (not to exceed Total Maximum Available = 750)
Switch#
Power Management Modes
The Catalyst 4500 series switches support two power management modes:
•Redundant mode—Redundant mode uses one power supply as a primar y power supply and the
second power supply as a back-up. If the primary power supply fails, the second power supply
immediately supports the switch without any disruption in the network. Both power supplies must
be the same wattage. A single power supply must have enough power to support the switch
configuration.
•Combined mode—Combined mode uses the power from all installed power supplies to support the
switch configuration power requirements. However, combined mode has no power redundancy. If a
power supply fails, one or more modules might shut down.