Semiconductor Fuses (F1) - ABB DCS880 series Hardware Manual

24

Semiconductor fuses (F1)

Aspects of fusing for the armature and field circuit of DC drives.
Unit configuration
Protection elements such as fuses or overcurrent trip circuits are required in all
cases to protect against further damage. In some configurations, this will entail the
following questions:
1. Where to place which protective element?
2. In the event of what faults will the element in question provide protection against
damage?
Conclusion for the armature circuit
Never use standard fusing instead of semiconductor fusing in order to save money
on the installation. In the event of a fault condition, the small amount of money saved
can cause the semiconductors or other devices to explode and cause fires.
Adequate protection against short circuit and earth fault, as depicted in the EN50178
standard, is possible only with appropriate semiconductor fuses.
Use DC fuses (2 of them) for all regenerative drives to protect the motor in case of a
fault during regeneration. DC fuses must be rated for the same current and voltage
as AC fuses, thus follows DC fuses = AC fuses.
F1
2-Q regenerative 2-Q non-regen.
Typical selection of DC fuses / high speed DC-breakers
Operation mode
no regeneration
seldom regeneration (< 10 %)
regeneration (10 % ... 30 %)
often regeneratio (> 30 %)
Planning the electrical installation
AC supply: public mains / plant's mains
3
F1 L1
Semiconductor Semiconductor
fuses
F1
DCS converter DCS converter DCS converter DCS converter
4-Q resp.
2-Q regenerative 2-Q regenerative
Semiconductor
fuses F2
M
SB_SIC_003_a.ai
3ADW000462R0101 DCS880 Hardware Manual e a
Cabinet
2
M
F2
2
For field supply
see next page
SB_SIC_002_b.ai
fuses
4-Q resp. 4-Q resp.
M
H1 ... H4
-
-
DC fuses
recommended
DC fuses strongly
recommended
The figure shows the arrangement
of the switch-off elements in the
armature-circuit. Further
information is available in the
Technical Guide.
H5 ... H8
-
-
high speed DC-breaker
recommended
high speed DC-breaker
strongly recommended