Cisco CATALYST 6509E 9 SLOT 15U CHASSIS NO POWER SUPPLY NO FAN TRAY Specification Guide

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Catalyst 6500 Series Switches Installation Guide
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Appendix A      Power Supply Specifications
  Power Supply Redundancy
Table A-21 Power Supply Redundancy
If you have two 
power supplies of 
and redundancy is 
Then
Equal wattage
Enabled
The total power drawn from both supplies is never greater than the 
capability of one supply. If one supply malfunctions, the other supply 
can take over the entire system load. Each power supply provides 
approximately half of the required power to the system. Load sharing 
and redundancy are enabled automatically; no software configuration is 
required.
Unequal wattage
Enabled
Both power supplies initially come online. For the Catalyst operating 
system, if the difference between the two power supply’s output 
wattage is less than 10% of the higher output wattage power supply, 
redundancy is enabled. If the difference is greater than 10%, the lesser 
wattage power supply is disabled.
For Cisco IOS, both power supplies come on. The total available 
wattage is the output wattage of the higher wattage power supply.
Equal or unequal 
wattage
Disabled
The total power available to the system is approximately 167 percent of 
the lower-wattage power supply. The system powers up as many 
modules as the combined capacity allows. If the higher-wattage power 
supply fails, the lower-wattage supply might also shut down due to 
overcurrent protection to prevent damage to the lower-wattage power 
supply.
Table A-22 Effects of Power Supply Configuration Changes
Configuration Change
Effect
Redundant to 
nonredundant
System log and syslog messages are generated.
System power is increased to approximately 167 percent of the 
lower-wattage power supply.
The modules marked as power-deny in the show module Status field 
are powered up if there is sufficient power.
Nonredundant to 
redundant
System log and syslog messages are generated.
System power is the power capability of the higher-wattage supply.
If there is not enough power for all previously powered-up modules, 
some modules are powered down and marked as power-deny in the 
show module Status field.
Equal wattage power 
supply is inserted with 
redundancy enabled
System log and syslog messages are generated.
System power equals the power capability of one supply. (Both 
supplies provide approximately one half of the total current.)
No change in the module status because the power capability is 
unchanged.