ABB DCS550 Series, Manual

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25
Electrical installation
3ADW000379R0501 DCS550 Manual e e
②
Semiconductor fuses (F1)
Aspects of fusing for the armature 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 Technical Guide.
Conclusion
Never use standard fusing instead of semi-conductor
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.
③
EMC filters (E1)
Filter in a grounded line (earthed TN or TT network)
The filters are suitable for grounded lines only, for example in public European 400 V
AC
lines. According to EN
61800-3 filters are not needed in insulated industrial networks with own supply transformers. Furthermore,
they could cause safety risks in such floating lines (IT networks). According to EN 61800-3 filters are not
needed in industrial zone (Second Environment) for DCS550 drives above 100 A
DC
rated current. For rated
currents below 100 A
DC
, the filter requirement is identical to Light Industry (First Environment).
Three-phase filters
EMC filters are necessary to fulfill the standard for emitted interference if a converter shall be run at a public
low voltage line, in Europe for example with 400 V
AC
. Such lines have a grounded neutral conductor. ABB
offers suitable three-phase filters for 400 V
AC
. For 440 V
AC
public low voltage lines outside Europe 500 V
AC
filters are available. Optimize the filters for the real motor currents:
−
i
Filter
= 0.8 * i
Mot max
; the factor 0.8 respects the current ripple.
Lines with 500 V
AC
and higher are not public. They are local networks inside factories, and they do not supply
sensitive electronics. Therefore, converters do not need EMC filters if they shall run with 500 V
AC
and more.
M
.
.
. .
.
.
3
2
2
SF_550_005_geräteschutz_a.ai
AC supply: public mains / plant's mains
Cabinet
M M
SF_800_009_fuses_a.ai
DCS converter
2-Q non-regen.
Semiconductor
fuses
Semiconductor
fuses
Semiconductor
fuses
4-Q resp.
2-Q regenerative
DCS converter