Owners Manual

power supply configuration is non-redundant (1 + 0). Power is supplied to the system only by the single power supply. When
configured in a 2+0 configuration, 1+1 redundancy will not be supported.
NOTE: If two power supplies are used, they must be of the same type and must have the same maximum output power.
NOTE: For AC power supplies, use only power supplies with the Extended Power Performance (EPP) label on the back.
Mixing power supplies from earlier generations of Dell DSS systems can result in a power supply 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.
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.
Figure 59. Removing the PSU blank
a. PSU blank
b. PSU bay
Installing and removing system components
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