Owners Manual

3. Complete the tasks listed in After working inside your system section in this document.
Related References
Safety instructions on page 46
Related tasks
Before working inside your system on page 47
After working inside your system on page 47
Power supply units
Your system supports one of the following:
• Two 750 W, or 1100 W AC PSU modules or
• Two 1100 W DC power supply modules or
• Two 750 W mixed mode PSU modules
NOTE: Titanium PSU is nominally rated for 200 V AC to 240 V AC input only.
NOTE: When two identical PSUs are installed, PSU redundancy (1+1 – with redundancy or 2+0 – without redundancy) is
configured in system BIOS. In redundant mode, power is supplied to the system equally from both PSUs when the Hot
Spare feature is disabled. When the Hot Spare feature is enabled, one of the PSUs will be put into standby when system
utilization is low in order to maximize efficiency.
NOTE: If two PSUs are used, they must be of the same maximum output power.
NOTE: For AC PSUs, use only PSUs with the Extended Power Performance (EPP) label on the back. Mixing PSUs from
previous generations of servers can result in a PSU mismatch condition or failure to turn on.
Hot spare feature
Your system supports the hot spare feature that significantly reduces the power overhead associated with power supply unit (PSU)
redundancy.
When the hot spare feature is enabled, one of the redundant PSUs is switched to the 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 PSUs active is more efficient than having one PSU in the sleep state, the active PSU can also activate the 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 falls below 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 available at Dell.com/idracmanuals.
Removing the power supply unit blank
Install the power supply unit (PSU) blank only in the second PSU bay.
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.
Follow the safety guidelines listed in the Safety instructions section.
Installing and removing system components
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