Siemens SIMATIC ET 200AL, System Manual

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Lightning protection and overvoltage protection
7.2 Lightning protection zone concept
Designing interference-free controllers
Function Manual, 06/2014, A5E03461486-AB
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7.2 Lightning protection zone concept
Introduction
Each building requires a coordinated protection zone concept. The grading of the protection
is of key importance for this. Sufficient protection can only be guaranteed if this grading
requirement is satisfied.
The lightning protection zone concept described in the standards IEC 62305-4 and
DIN EN 62305-4 is used for this purpose. The lightning protection zone concept groups
devices and areas that have the same risk potential and can be wired to arresters of the
same type.
Use overvoltage protection devices at the transitions of the lightning protection zones based
on the requirements. Install the overvoltage protection devices at an appropriate location
such as the main or sub-distribution board.
Principle of the lightning protection zone concept
The principle behind the lightning protection zone concept is the division of the areas to be
protected from overvoltages, for example buildings, into lightning protection zones based on
EMC considerations.
Schematic diagram of the lightning protection zone concept
The following is a schematic diagram of the lightning protection zone concept in a physical
structure.
Figure 7-1 Division of a structural system into lightning protection zones