Hot Spare Feature; Removing The Power Supply Unit Blank - Dell DL4300 Owner's Manual

NOTE: When two identical PSUs are installed, power supply 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 Hot Spare is disabled. When Hot Spare is enabled, one of
the PSUs will be put into standby when system utilization is low in order 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
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.
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