PowerEdge System Components

Overview

Desktop PCs commonly use a standard power supply plugged directly into the system board. Servers have more complex power requirements than a desktop PC. The needs vary according to the role of the server but may include the ability to:

• Draw power from multiple power supplies simultaneously.

• Automatically switch from a failed power supply to a backup power supply.

• Have power supplies swapped out of the system without powering down.

• Report status of the power supplies to the system.

Redundant Power Supplies

A PowerEdge system may be equipped with redundant power supplies in an N + 1 configuration. In an N + 1 configuration, the N represents the number of power supplies necessary for the system to function properly. The +1 is reserved for redundancy.

If one of the two active power supplies fails, the third power supply will automatically switch over to provide the necessary power to keep the system running. The failed power supply may then be hot swapped for a replacement to restore the system's redundant power without shutting down.

The image shows the middle power supply partially removed. Notice the green and red lights on each power supply that provide visual confirmation of the power supply status. The red light will illuminate when a power supply is in a failed state, making it possible to quickly identify and replace the nonfunctional unit.