Service Manual

GSM-205-523
Replacing a power supply module (PSM)
31st Oct 01
Maintenance Information: Horizon macro indoor
68P02902W09-B
CONTROLLED INTRODUCTION
Maint. 2–15
Replacing a power supply module (PSM)
Introduction
to PSM
replacement
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, or for the hold-up battery unit. A replacement
PSM can be inserted into a vacant slot without powering down, thereby avoiding
any need to take the cabinet out of service.
Preconditions
for PSM
replacement
Replacement PSM must be of appropriate type for the cabinet (+ 27 V dc,
–48/60 V dc, or 100/240 V ac).
CAUTION
Replacement PSM must have the correct input voltage
rating for the cabinet.
View of PSM
Figure 2-7 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 2-7 View of PSM with key features identified
NOTE
There are several manufacturers of the PSMs. All PSMs of
the same type are fully compatible with each other,
regardless of manufacturer.