User's Manual Part 3

Power Supply Module (PSM)
9-18 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU MAY 2004
PRELIMINARY
Introduction
The procedures in this section cover only the Power Supply Module
(PSM). The PSM occupies the first slot in the CCP2 Shelf.
System Impact/Consideration
The PSM supplies DC power to the cards/modules of the CCP2 Shelf. If
the module needed replacing it will cause an interruption in call
processing.
Required Items
Documents
None.
Tools
None.
Replacement Unit
For –48 VDC – One Power Supply Module (SGPN4053)
For +27 VDC – One Power Supply Module (STPN4009)
The connector keying for the PSM is different for each
version to prevent using the wrong module.
NOTE
Prerequisite
Coordinate this repair task with the OMC–R operator.
IMPORTANT
*
Contact the OMC–R operator before performing the replacement
procedure. Tell the operator that the PSM will be replaced and that
alarms can be expected.
Upon completion of the replacement procedure, have the OMC–R
operator verify that old alarms are cleared and that no new ones are
reported.
When this module is removed, the BTS will shut down
because power to CCP2 Shelf will be interrupted. It is
recommended that replacing the PSM be performed during
a maintenance window.
IMPORTANT
*
9