Siemens SIMOCODE pro System Manual page 115

The table below shows decoupling module requirements for different
network forms and configurations (star networks, delta networks and
single-phase networks):
Star networks:
Star network
4-wire, star
grounded with low
impedance
4-wire, star
grounded with high
impedance
3-wire, star
grounded with low
impedance
3-wire, star
grounded with high
impedance
3-wire, star
insulated
Table 1-20: Decoupling module requirements for star networks
SIMOCODE pro
GWA 4NEB 631 6050-22 DS 03
Network configuration
L1
L2
L3
N
PE
L1
L2
L3
R
N
PE
L1
L2
L3
PE
L1
L2
L3
R
PE
L1
L2
L3
PE
System description
Decoupling Note
module
required
No TN-S system
according to
IEC 60364
Yes -
No TN-C system
according to
IEC 60364
Yes -
Yes IT system according
to IEC 60364
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