Service Manual

GSM-204-523
Replacing a power supply module (PSM)
31st Oct 01
Maintenance Information: Horizon macro outdoor
68P02902W04-A
CONTROLLED INTRODUCTION
Maint. 3–19
Replacing a power supply module (PSM)
Introduction
to PSM
replacement
Only one type of PSM is used in Horizon macro outdoor, –48V dc positive earth.
There are three slots for PSMs. A single PSM can power a cabinet containing
up to three CTUs therefore, a cabinet populated with six CTUs only requires two
PSMs to be fully operational. The third slot can be used for an additional power
supply to provide redundancy. A replacement PSM can be inserted into a vacant
slot without powering down, thereby avoiding any need to take the cabinet out
of service.
View of PSM
Figure 3-9 shows a view of the PSM with key features identified.
PSM FRONT PANEL
AIR VENTS ON
ENTIRE TOP AND
BOTTOM PANELS
GREEN LED
ACTIVE
RED LED
ALARM
OUTPUT DISABLE
SWITCH
M4 MODULE ATTACHMENT
SCREWS
Figure 3-9 View of PSM with key features identified