Service Manual

GSM-204-323
The outdoor power supply module (TOPSM)
31st Oct 01
Tech. 4–26
Technical Description: Horizon macro outdoor
CONTROLLED INTRODUCTION
68P02902W02-A
The outdoor power supply module (TOPSM)
TOPSM
overview
This section describes the TOPSM used in the Horizon macro outdoor cabinets.
Three TOPSMs provide adequate operating power for all the modules within the
base station and full battery charging (including external extended battery
backup). Under normal operating conditions, two TOPSMs provide sufficient
power to operate all BTS modules and trickle charge the batteries and the third
TOPSM then provides redundancy.
View of TOPSM
Figure 4-17 shows a view of the TOPSM.
Figure 4-17 The outdoor power supply module (TOPSM)
TOPSM
functional
description
The TOPSM system is a power factor-corrected, wide input, ac power supply
module. Each TOPSM is a switching type ac/dc power converter with the
following regulated dc output:
 –55 V at 23.5 A (maximum output current).
 1200 W (nominal).
The outputs of each TOPSM are connected in parallel by the power supply
cage. The TOPSMs in the system actively share the load.
The regulated dc output is fed through the multilayer busbar to the interface
panel and the dc circuit breaker panel to power the base station.