Uepo Switch - IBM pSeries 670 Service Manual

UEPO Switch

The UEPO (Unit Emergency Power Off) switch is accessible through the external cover. The switch
contains a room emergency power off (EPO) interlock connector and bypass switch, a dual element rack
service amber LED (one element driven per bulk power controller, a service complete button (white) and
start service button (green), an off button and four thermistors for BPC ambient temperature sensing. The
UEPO switch is shown in the following figure.
1 UEPO Front Panel
2 UEPO Side Panel
3 UEPO Rear Panel
4 J00 Connector Front BPA (Back)
5 J01 Connector Rear BPA (Back)
6 Room EPO Bypass Interlock
The UEPO switch disables 350 V bulk power conversion and isolates all battery power to the battery
compartments, without having to disconnect the heavy power cords under the customer's raised floor.
At the system level, the UEPO switch is connected to each of the two BPCs through two interface
connectors. The switch can be concurrently replaced by forcing the BPCs into UEPO bypass mode, using
the small slide switches on the face of the BPCs. The switch is mounted in the side pocket area of the
rack and remains stationary when the front cover of the system is opened. The service buttons are used
by service personnel to repair the power subsystem. If the system is off when the service complete button
is pressed, the system will power on. A sliding plastic cover over the red switch prevents it from being
accidentally activated in the customer environment.
1 2
11
10
9
8
6
7
3
4
5
6
7 J02 Connector
8 Power Switch
9 System Fault LED
10 Start Service Button (Green)
11 Service Complete Button (White)
Chapter 1. Reference Information
19