94 Installing System Components
Power Supplies
Your system supports two 
1100 W
 power supply modules.
If two power supplies are installed, the second power supply provides hot-
swappable, power redundancy. In redundant mode, the system distributes the 
power load across both power supplies to maximize efficiency. When a power 
supply is removed with the system powered on, the full power load is picked 
up by the remaining power supply. Table 3-1 lists the power supply 
redundancy modes.
Removing a Power Supply
  CAUTION: The system requires one power supply for normal operation. On 
power-redundant systems, remove and replace only one power supply at a time in 
a system that is powered on.
1
Disconnect the power cable from the power supply and remove the Velcro 
straps that bundle and secure the system cables.
  NOTE: You may have to unlatch and lift the optional cable management arm if 
it interferes with power-supply removal. For information about the cable 
management arm, see the system’s rack documentation. 
2
Press the release latch and pull the power supply straight out to release it 
from the power distribution board and clear the chassis.
If you are permanently removing the power supply, you must install a 
power supply blank to ensure proper system cooling. See "Installing the 
Power Supply Blank" on page 96.
Table 3-1. Power Supply Redundancy Modes
Number of Power Supplies Redundancy Mode System Configuration
1 1+0 Nonredundant 
configuration
2 1+1 Redundant configuration
book.book  Page 94  Thursday, February 18, 2010  2:06 PM