Power Supply Units; Hot Spare Feature; Removing A Redundant Power Supply Unit - Dell EMC NX430 System Owner's Manual

Power supply units

Your system supports 350 W AC redundant power supply units (PSUs).
NOTE: If two PSUs are used, they must be of the same type and have the same maximum output power.
When two identical PSUs are installed, the PSU configuration is redundant (1 + 1). In redundant mode, power is supplied to the system
equally from both PSUs to maximize efficiency.
When only one PSU is installed, the PSU configuration is non-redundant (1 + 0). Power is supplied to the system only by the single PSU.
In a non-redundant configuration, install a PSU blank in the empty PSU slot.

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 a redundant 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 requires one power supply unit (PSU) for normal operation. On power-redundant systems, remove and
replace only one PSU at a time in a system that is powered on.
1 Follow the safety guidelines listed in the Safety instructions section.
2 Disconnect the power cable from the power source.
3 Disconnect the power cable from the PSU and remove the straps that bundle and secure the system cables.
4 Unlatch and lift the optional cable management arm if it interferes with PSU removal. For information about the cable management
arm, see the system's rack documentation.
Step
Press the release latch and pull the PSU out of the chassis.
80 Installing and removing system components