NOTE: 495 W, 750 W, and 1100 W Platinum power supplies are nominally rated for 100 VAC to 240
VAC input.
750 W Titanium and 1600 W Platinum power supplies are nominally rated for 200 VAC to 240 VAC
input.
1100 W DC power supply is nominally rated for –(48-60) VDC input.
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: For AC power supplies, use only power supplies with the Extended Power Performance (EPP)
label on the back. Mixing PSUs from previous generations of servers can result in a power supply
mismatch condition or failure to turn on.
NOTE: When you have more than two GPU cards on your system, you will need two 1100 W PSUs
installed on your system.
Hot spare feature
Your system supports the hot spare feature that significantly reduces the power overhead associated with
power supply 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 an AC power supply unit
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.
CAUTION: The system needs one power supply for normal operation. On power-redundant
systems, remove and replace only one power supply at a time in a system that is powered on.
149
