NOTE:
For more information, see the Technical specifications section.
CAUTION:
If two PSUs are installed, both the PSUs must have the same type of label. For example, Extended Power
Performance (EPP) label. Mixing PSUs from previous generations of NAS systems is not supported, even if the PSUs have the
same power rating. Mixing PSUs will result in mismatch condition or failure to turn the system on.
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 is put into the sleep mode 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.
This section contains information about the hot spare features, removal and installation of the power supply blank, and AC power supply
unit.
Identifier
GUID-7F2B298A-0D69-4335-AA98-BF14C87E6A15
Status
Released
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 system 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 of PSU rated power wattage, then the redundant PSU is switched to the active
state.
•
If the load on the active PSU falls below 20 percent of PSU rated power wattage, 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, see the iDRAC User’s Guide available at
Dell.com/idracmanuals
.
Identifier
GUID-F1C9F34B-CCE7-466C-9893-619C61E4F2D3
Status
Released
Removing a power supply unit blank
Prerequisite
Follow the safety guidelines listed in
Step
If you are installing a second 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.
Installing and removing system components
145
