ABB 3BHE035301R1002 UNITROL 1010 excitation system control unit
Fuses (F3.x) and fuse holders for field circuitDepending on the protection strategy different types of fuses are used. The fuses can be sized according to the
maximum field current. In this case take the fuse, which fits to the rated field current levels. If the field converter
is connected to two phases of a network, two fuses should be used. In case the unit is connected to one phase
and neutral only one fuse at the phase can be used. The table below lists the fuse currents depending on the
table above.
Fuse (F3.1) KTK25 included in FEX-425-Int package. H5 field fuses are external. H6 field fuses are internal.
Fuses and fuse holders for the field circuit.
Field converter type Field
current
F3.1 F3.2 F 3.3
DCF803-0016 IF 6 A 10 A 660 V UR OFAA 00 H10 10 A
FEX-425-Int IF 12 A 16 A 660 V UR OFAA 00 H16 16 A
DCF803-0035 IF 16 A 25 A 660 V UR OFAA 00 H25 25 A
DCF803-0050
DCF804-0050
FEX-425-Int
DCF803-0035
DCF803-0050
DCF804-0050
IF 25 A 50 A 660 V UR OFAA 00 H50 35 A
DCF803-0035
DCF803-0050
DCF804-0050
IF 35 A 50 A
DCF803-0050
DCF804-0050
IF 50 A 80 A 660 V UR OFAA 00 H80 63 A
DCF803-0060
DCF804-0060
IF 60 A 80 A
Type of protection elements Semiconductor fuse
fuse holder
OFAZ 00 S3L
LV HRC type for 690 V,
fuse holder
OFAZ 00 S3L
Circuit breaker
for 500 V or 690 V

Single-phase autotransformer (T3) for field circuit (adapt voltage)
The field converters insulation voltage is higher than its rated voltage (see chapter Accessories). This provides
the possibility in systems with more than 500 V mains voltage to supply the field converter directly. An
autotransformer is used to match the mains voltage to the field voltage. Moreover, the autotransformer
reduces the voltage ripple. Different autotransformer types (primary voltages from 400 ... 500 V and from 525 ...
690 V) with several rated currents are available.
Autotransformer data, details see chapter Autotransformer (T3).
Field converter type Field current Autotransformer type
DCF803-0016
FEX-425-Int
DCF803-0035
DCF803-0050
DCF804-0050
IF 6 A
IF 12 A
IF 16 A
Uprim = 500 V
T 3.01
T 3.02
T 3.03
FEX-425-Int
DCF803-0035
DCF803-0050
DCF804-0050
IF 30 A T 3.04
DCF803-0050
DCF804-0050
IF 50 A T 3.05
DCF803-0060
DCF804-0060
IF 60 A T 3.16 (on request)
DCF803-0016
FEX-425-Int
DCF803-0035
DCF803-0050
DCF804-0050
IF 6 A
IF 12 A
IF 16 A
Uprim = 600 V
T 3.11
T 3.12
T 3.13
FEX-425-Int
DCF803-0035
DCF803-0050
DCF804-0050
IF 30 A T 3.14
DCF803-0050
DCF804-0050
IF 50 A T 3.15
DCF803-0060
DCF804-0060
IF 60 A T 3.16 (on request)
DCF803-0050
DCF804-0050 IF 6 A
IF 12 A
IF 16 A
IF 30 A
IF 50 A
Uprim = 690 V
T 3.11
T 3.12
T 3.13
T 3.14
T 3.15
DCF803-0060
DCF804-0060
IF 60 A T 3.16 (on request)