Assembling and Installing Systems
A-28
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
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:
CPU
SV
10 mm
2
PE
Switchgear cubicle1
L1L2L3NPE
Lightning-protection 0, field side zone
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
Figure A-7 Sample Circuitry for Networked S7-400 PLCs