Planning the electrical installation
40
3ADW000462R0401 DCS880 Hardware manual e d
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?
The figure shows the arrangement of the
switch-off elements in the armature-circuit.
Further information is available in the
.
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.
Typical selection of DC fuses / high speed DC-breakers.
Operation mode
H1 ... H4
H5 ... H8
No regeneration
-
-
Seldom regeneration (< 10 %)
-
-
Regeneration (10 % ... 30 %)
DC fuses
recommended
High speed DC-breaker
recommended
Often regeneratio (> 30 %)
DC fuses strongly
recommended
High speed DC-breaker
strongly recommended
2
SB_SIC_002_b.ai
F1
L1
F2
M
2
3
Cabinet
For field supply
see next page
AC supply: public mains / plant's mains
SB_SIC_00
3
_a.ai
F1
DCS converter
4-Q resp.
2-Q regenerative
M
F1
DCS converter
4-Q resp.
2-Q regenerative
M
DCS converter
4-Q resp.
2-Q regenerative
Semiconductor
fuses F2
DCS converter
2-Q non-regen.
Semiconductor
fuses
Semiconductor
fuses