Dell PowerEdge R900 - Manual (Page 68)

68 Installing System Components
Power Supplies
Two power supplies power your system.
NOTE: Your system can operate using only one power supply, but with severely
degraded performance.
Removing a Power Supply
NOTICE: The system requires one power supply for the system to operate normally.
The system is in the redundant mode when two power supplies are installed and
both power supplies are connected to an AC power source. Remove and replace
only one power supply at a time in a system that is powered on. Operating the
system with only one power supply installed and without a power supply blank
installed for extended periods of time can cause the system to overheat.
NOTICE: If only one power supply is installed, it must be installed in power supply
bay (1).
NOTICE: If you connect the system to a power source in the range of 120 to 220
VAC, and if two power supplies are installed, the second power supply serves as a
redundant, hot-plug power source.
1 If your system has a single power supply, remove power from the system
and all attached peripherals. For a redundant system, you can leave the
system running and proceed to the next step.
2 Disconnect the power cable from the power source.
3 Disconnect the power cable from the power supply.
4 Depress the power supply latch and then pull the power supply lever to
extract the power supply out of the chassis. See Figure 3-6.
5 Pull the power supply straight out to clear the chassis.