User Manual

Table Of Contents
BFU Battery Fuse Unit
1 Product Overview
The Battery Fuse Unit (BFU) supervises, connects and disconnects the
batteries at low voltage in the following RBSs:
RBS 2102
RBS 2103
Due to its own default values, the BFU can operate independently from the rest
of the control system in the RBS. If the communication between the ECU and
the BFU fails, the BFU will still function.
1.1 Main Functions
The BFU has the following main functions:
Communication with the ECU
Disconnection of main load from batteries
Alarm handling
Communication with the ECU
The BFU measures the following values and transfers them to the ECU via
the opto cable:
Battery voltage
Battery current
The difference between the voltage level in the batteries and the system
voltage from the rectifiers
Battery temperature (this value is used by the ECU to send information to
the rectifiers to change the output level on the voltage so that the batteries
can be charged in a proper way)
Disconnection of Main Load from Batteries
The BFU has a measuring function and disconnects the main load from
the batteries if there is a risk of damaging the batteries due to a too-high
temperature or deep discharging.
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EN/LZT 720 0233 Uen R1A