Cisco 4124 Benutzerhandbuch

Catalyst 4006 switch has two standard power supplies and one optional redundant 
power supply. Two standard power supplies are required to operate a 
Catalyst 4006 switch. Systems with three power supplies will share the load with 
each unit providing approximately one-third of the total load.

When power is removed from one power supply on a Catalyst 4003 switch that 
has two power supplies, the redundant power feature causes the second power 
supply to produce full power.

When power is removed from one power supply on a Catalyst 4006 switch that 
has three power supplies, the other two power supplies produce full power. Load 
sharing returns when all three power supplies are on.

To replace a power supply, see the 

.

The AC power supply has two front-panel LEDs:

The LED labeled GOOD is green when the power supply is connected and 
operating normally.

The LED labeled FAIL is red when there is a problem with the power supply.

Each power supply has a built-in fan. Air enters the front of the power supply 
(power-input end) and exits through the back. An air dam keeps the airflow 
separate from the rest of the chassis, which is cooled by the system fan assembly.

When you install and power-on a second power supply on a Catalyst 4003 switch, 
it provides approximately half of the required power to the system. If one power 
supply fails, the other power supply immediately assumes full power to maintain 
uninterrupted system operation. 

When you install and turn on a third power supply on a Catalyst 4006 switch, it 
provides approximately one-third of the power required by the system. If one 
power supply fails, the other two immediately generate full power to maintain 
uninterrupted system operation.