7
05.01
7.3 Overcurrent protective devices, transformers and main switch
7-215
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
7.3
Overcurrent protective devices, transformers and main
switch
7.3.1
Assignment of the line fuses to the NE modules
Fuses or circuit breakers are necessary to protect the cables against short–cir-
cuit/ground fault, to limit any damage to the converter, provide protection
against electric shock and to avoid fire in the case of a fault. The overvoltage
protective devices must be located before the terminals of the drive lineup (line
filter or HFD reactor)!
!
Danger
Overvoltage protective devices only on the primary side of a transformer, which
may be possibly used, are not sufficient to protect the converter or protect
against fire!
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. 7-8 is
not exceeded.
Circuit breakers (Table 7-6) or alternatively, fuses (Table 7-7) should be used.
The appropriate protection measure should be selected corresponding to the
local situation from Table 7-5.
Table 7-5
Selection aid for line supply protection measures
Short–circuit power
as specified in the
Configuration Manual
Loop resistance
allows short–circuit
current
T
ransformer vector group
can be loaded
asymmetrically
Protection
Risk
n
n
n
Fusible links in accordance with the documentation when tripped in
less than 10 ms (
or
,
,
,
)
Minimum residual
risks
n
–
n
Circuit–breaker with parameterized magnetic short–circuit deactiva-
tion adapted to the loop resistance (
,
,
,
)
Minimum residual
risks
n
–
–
RCD switch (AC/DC–sensitive
type B) and isolating transformer or circuit–breaker with residual
current monitor (RCM) (
,
)
Incorrect trips for
large converter
configurations
with a high rated
power
–
n
n
Fusible links in accordance with the documentation that can be
tripped in less than 10 ms
(
in accordance with test,
,
,
,
)
Excessively high
line dips for other
loads
–
–
–
RCD switch (AC/DC–sensitive
type B) and isolating transformer or circuit–breaker with residual
current monitor (RCM) (
,
)
Excessively high
line dips for other
loads
1) Assignment of the possible circuit breakers to the NE modules, see Table 7-6
Assignment of fuses to the NE modules, see Table 7-7
7 Line Supply Connection
02.12
