Owners Manual

• Two 495 W, 750 W, or 1100 W AC power supply modules or
• Two 1100 W DC power supply modules or
• Two 750 W mixed mode power supply modules
NOTE: Titanium power supply unit is nominally rated for 200 VAC to 240 VAC input only.
NOTE: When two identical PSUs are installed, power supply redundancy (1+1 – withredundancy or
2+0 – without redundancy) is configured in system BIOS. In redundant mode, power is supplied to
the system equally from both PSUs when Hot Spare is disabled. When Hot Spare is enabled, one of
the PSUs are put into standby when system usage is low to maximize efficiency.
NOTE: If two power supply units are used, they must be of the same maximum output power.
NOTE: For AC power supply units, use only power supply units with the Extended Power
Performance (EPP) label on the back. Mixing power supply units from previous generations of
servers can result in a power supply unit mismatch condition or failure to power on.
Hot Spare feature
Your system supports the Hot Spare feature that significantly reduces the power overhead associated
with PSU redundancy.
When the Hot Spare feature is enabled, one of the redundant power supplies is switched to a sleep state.
The active PSU supports 100 percent of the load, thus operating at higher efficiency. The PSU in the sleep
state monitors output voltage of the active PSU. If the output voltage of the active PSU drops, the PSU in
the sleep state returns to an active output state.
If having both power supplies active is more efficient than having one PSU in a sleep state, the active PSU
can also activate a sleeping PSU.
The default PSU settings are as follows:
• If the load on the active PSU is more than 50 percent, then the redundant PSU is switched to the
active state.
• If the load on the active PSU is less than 20 percent, then the redundant PSU is switched to the sleep
state
You can configure the Hot Spare feature by using the iDRAC settings. For more information about iDRAC
settings, see the Integrated Dell Remote Access Controller User’s Guide at Dell.com/support/home.
Removing an AC power supply unit
Prerequisites
CAUTION: Many repairs may only be done by a certified service technician. You should only
perform troubleshooting and simple repairs as authorized in your product documentation, or as
directed by the online or telephone service and support team. Damage due to servicing that is
not authorized by Dell is not covered by your warranty. Read and follow the safety instructions
that are shipped with your product.
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.
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.
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