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S7-300 Automation System, Hardware and Installation: CPU 31xC and CPU 31x
A5E00105492-03
12-25
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The sample in the figure below shows you how install an effective surge protection
for 2 networked S7-300 PLCs:
CPU
SV
10 mm
2
PE
Switchgear cubicle 1
L1
L2
L3
N
PE
Lightning-protection zone 0, field side
Lightning-protection zone 1
Lightning-protection zone 2
SM
MPI
CPU
SV
10 mm
2
PE
Switchgear cubicle 2
SM
MPI
Lightning-protection zone 2
1
4
5
3
6
2
4
2
5
4
4
6
3
7
3
Figure 12-7 Sample circuit for networked S7-300 PLCs