7
05.01
7.3 Line supply fuses, transformers and main switch
7-208
© Siemens AG 2008 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 05/2008 Edition
7.3 Line supply fuses, transformers and main switch
7.3.1 Assignment of the line fuses to the NE modules
Fuses are necessary for line protection, to limit damage to the converter, to pro-
tect against electrical shocks, and to avoid fire in case of a fault.
Fuses and plant conditions, such as loop resistance and short–circuit power,
must be harmonized with each other so that the limit curve shown in Fig. 7-7 is
not exceeded.
Fusible links (Table 7-4) or, as alternative, circuit–breakers (Table 7-5) must be
used.
Table 7-3 should be used to choose the protection measure appropriate for the
local conditions.
Fusible links that can be used: LV HRC, D, DO size with gL characteristics. We
recommend the SIEMENS fuse types, listed below, that do not restrict/limit the
main power data of the NE modules.
Table 7-3 Selection aid for line supply protection measures
Short–circuit power
as specified in the
Configuration Manual
Loop resistance
allows short–circuit
current
Transformer vector group
can be loaded
asymmetrically
Protection
Risk
Risk when the
required protection
is not provided
X X X
Fusible links in accordance with the
documentation when tripped in less
than 10 ms ( or , , , )
Minimum accept-
able
Excessively large fusible
links increase the device
damage in case of fault or
can cause fire
X – X
Circuit–breaker with parameterized
magnetic short–circuit deactivation
adapted to the loop resistance (,
, , )
Minimum accept-
able
Fusible links rather than
circuit–breakers can cause
increased device damage or
fire
X – –
RCD switch (AC/DC–sensitive
type B) and isolating transformer or
circuit–breaker with residual current
monitor (RCM) (, )
Spurious tripping
for large configu-
rations
Device damage or fire
– X X
Fusible links in accordance with the
documentation that can be tripped in
less than 10 ms
( in accordance with test, , ,
, )
Excessive line
supply dips for
other loads
Excessively large fusible
links increase the device
damage in case of fault or
can cause fire
– – –
RCD switch (AC/DC–sensitive
type B) and isolating transformer or
circuit–breaker with residual current
monitor (RCM) (, )
Excessive line
supply dips for
other loads
Device damage or fire
7 Line Su
l
Connection 05.08
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