The server has a unit emergency power off (UEPO) switch on the
front of the first frame (A Frame). Refer to the following figure, which shows
a simplified UEPO panel.
Figure 1. Unit emergency power
off figure
When the switch is reset, the utility power is confined to the system power compartment. All volatile data will be lost.
It is possible to attach the computer room emergency power off (EPO) system to the system UEPO. When this is done, resetting the computer room EPO disconnects all power from the power cords and the internal battery backup unit, if it is provided. All volatile data will be lost in this case also.
If the room EPO is not connected to the UEPO, resetting the computer room EPO removes ac power from the system. If the interlock bypass feature is used, the system remains powered for a short time based on system configuration.