User Manual

Table Of Contents
BFU Battery Fuse Unit
4 Function Description
This section describes the functions of the following BFU units:
Auxiliary fuse (RBS 2102 only)
Circuit Breaker (Fuse)
Contactor
Control and supervision circuits
Power circuit
Aux
Fuse
P003446A
Contactor
(Fuse)
Circuit
breakers
DC ECU
Supply
Control
and supervision
DC System
voltage
ECU
Opto link
BFU
Power
circuit
DC
Figure 1 BFU block diagram
Auxiliary fuse
When the cabinet is running on DC power the ECU is
connected to a fuse marked "Aux" in the BFU.
Circuit Breaker
(Fuse)
Connects the batteries t
o the internal system voltage
bar. The circuit breaker should be set in position normal.
Contactor
Disconnects the batteries from the power system. The
BFU, while under ECU supervision, controls the battery
usage as a back-up source of DC power to the RBS and
disconnects the batteries when the output DC voltage
becomes too low. It also regulates the DC power supply
for charging the back-up batteries.
Control and
supervision
The control and supervision circuits in the BFU
constantly measure the temperature of the batteries and
transfer the data to the ECU. If the battery temperature
5 (10)
EN/LZT 720 0233 Uen R1A