Owners Manual

PSUs
Your system supports one of the following:
● Two 750 W AC PSU 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.
Steps
If you are installing a second power supply unit (PSU), remove the PSU blank in the bay by pulling the blank outward.
CAUTION:
To ensure proper system cooling, the PSU blank must be installed in the second PSU bay in a non-
redundant configuration. Remove the PSU blank only if you are installing a second PSU.
88 Installing and removing system components