Siemens Simatic 6ES7 157-0AD81-0 A0 Series

Wiring
4-5
DP/PA Link and Y Link Bus Couplings
A5E00193841-011
Ground bus in the cabinet
N
M
L1
L +
M
PS
L1
L2
L3
N

Cabinet
Low-voltage distribution, e. g.
TN-S system (3 x 400 V)
PE
Rail
IM 157 or
DP/PA coupler
Elec-
tronics
Figure 4-2 Configuration with a grounded supply
4.1.3 Operation with ungrounded reference potential
Application
In extended systems, it may be necessary to operate the modules with
ungrounded reference potential for the purposes of ground fault monitoring, for
example. This is the case in the chemical engineering industry or in power stations.