Siemens SIMATIC Operating Instructions Manual page 43

Pulse-shaped interference
Asymmetrical connection
Symmetrical connection
Protecting the ET 200pro With Fail-Safe Modules Against Overvoltages
If your equipment makes protection against overvoltage necessary, we recommend that you
use an external protective circuit (surge filter) between the load voltage supply and the load
voltage input of the terminal modules to ensure surge immunity for the ET 200pro with fail-
safe modules.
Note
Lightning protection measures always require a case-by-case examination of the entire
system. Virtually complete protection against overvoltages, however, can only be achieved if
the entire building surrounding the system has been designed for protection against
overvoltages. In particular, this involves structural measures in the building design phase.
Therefore, for detailed information regarding protection against overvoltages, we recommend
that you contact your Siemens representative or a company specializing in lightning
protection.
ET 200pro Distributed I/O System - Fail-Safe Modules
Operating Instructions, 05/2007, A5E00394073-02
Tested with
1 kV (supply line)
1 kV (signal line/data line)
2 kV (supply line)
0.5 kV (supply line)
0.5 kV (signal line/data line)
1 kV (supply line)
1 kV (signal line/data line)
General Technical Specifications
6.2 Electromagnetic Compatibility
Degree of severity
2
3
2
3
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