Power Supply Units; Redundant Ac Power Supply Unit - Dell poweredge t330 Owner's Manual

Power supply units

Redundant AC power supply unit

Your system supports up to two 495 W (Platinum) AC power supply units (PSUs).
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.
CAUTION: 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 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 redundancy.
When the hot spare feature is enabled, one of the redundant PSUs is switched to the sleep state. The
active PSU supports 100% 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%, then the redundant PSU is switched to the active state.
• If the load on the active PSU falls below 20%, 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 at Dell.com/idracmanuals.
Removing a redundant 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 came with the product.
CAUTION: The system requires one power supply unit (PSU) for normal operation. On power-
redundant systems, remove and replace only one power supply at a time in a system that is
powered on.
1. Ensure that you follow the
2. Disconnect the power cable from the power source and from the PSU you intend to remove and
remove the cables from the strap.
Safety instructions.
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