Installation Instructions

220 V AC P ower Supply Module (PSM) Shelf Chapter 10: PSM Shelf R eplacement Procedures
PSM shelf alarm and control I/O interconnection
Each PSM slot has a bulkhead connector . The status/alarm I/O signals of each of these slot
connectors are interconnected to the ALARM & CONTROL connector on the front of the 220 V
AC PSM shelf .
Each 220 V AC PSM has a rear panel status/alarm drawer connector that mates with the
bulkhead connector in the PSM slot of the PSM shelf . The I/O signals of this connector are
interconnected to the ALARM & CONTROL connector on the front of the 220 V AC PSM shelf .
This connector is cabled to the S SI front panel PSM connector . This allows the PSM alarm &
status to be monitored by the S SI. It also allows the front panel LEDs and module enable to
be controlled by the S SI.
PSM alarm & status signal inputs are current share, temp alarm, converter fail, fan fail, high
temp, low bus voltage, input voltage loss, presence, and EID .
The current share signal goes directly from one PSM to the others via PSM shelf backplane
looping without going to the S SI. Based on PSM alarm & status, the S SI outputs signals to
control the state of the LEDs.
The PSM shelf ALARM & CONTROL cable also contains the PSM enable line which
must be grounded at the S SI in order for the PSM to operate.
System impact/considerations
P erforming this replacement procedure will cause BTS downtime and interrupt all
call processing.
Prior to replacing the 220 V AC PSM shelf , the UBS Macro BTS site signaling is shutdown (i.e.,
disable the BTS site) then the UBS Macro BTS frame is powered down.
Table 10 -3 220 V AC PSM Shelf R eplacement Conditions
FRU
Ref Designator What to Shutdown...
220 V AC P ower
Supply Module
(PSM) shelf
220 V AC PSM shelf Shutdown site signaling functions and then power
down the frame.
10 -10 68P09283A64 -3
FOA SEP 2007