Service Manual

GSM-205-323
Hold-up battery module
31st Oct 01
Tech. 4–8
Technical Description: Horizon macro indoor
CONTROLLED INTRODUCTION
68P02902W07-B
Functional
description
During normal operation the batteries are charged by an internal battery
charger. The charger provides battery temperature compensation to protect the
batteries. In the case of external ac power supply failure, the unit automatically
switches the BTS to battery operation. The hold-up battery module indicates
failure alarms to the OMC-R, through the Horizon
macro alarm board.
Low voltage disconnect (LVD)
The hold-up battery module has an LVD function to protect the batteries from
deep discharge. The battery does not discharge when not in the system or after
operation of the low voltage disconnect.
Hold-up battery
module
functional
diagram
Figure 4-4 shows the electrical layout of the hold-up battery module.
2  12 V
LEAD ACID BATTERIES
LVD
BATTERY
CHARGER AND
INPUT POWER
DETECT
Transistor
switch
To backplane
dc bus
19 to 27.5 V
External
supply
88 to 270 V ac
Enable
Fuse
Input
detect
Figure 4-4 Hold-up battery module electrical layout