Siemens Simatic S7-400

Assembling and Installing Systems
A-28
Automation System S7-400 Hardware and Installation
A5E00850741-01
A.9.4 Sample of a Surge Protection Circuit for Networked S7-400
PLCs
Sample Circuit
The sample in the figure A-7 shows you how install an effective surge protection for
2 networked S7-400 PLCs:
CPUSV
10 mm
2
PE

Switchgear cubicle1
L1
L2
L3
N
PE


Lightning-protection 0, field side zone
Lightning-protection zone 1
Lightning-protection zone 2
SM

MPI
CPUSV
10 mm
2
PE

Switchgear cubicle 2

SM

MPI

Lightning-protection zone 2






Figure A-7 Sample Circuitry for Networked S7-400 PLCs