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Appendix
A.5 Lightning and overvoltage protection
A.5
Lightning and overvoltage protection
A.5.1
Overview
Introduction
One of the most common causes of failure is overvoltage caused by:
● Atmospheric or
● Electrostatic discharge
The concepts or measures for protection from overvoltages is based on the lightning
protection zone concept.
The rules to be complied with for the transitions between the individual lightning protection
zones are presented here.
Note
This section can only provide you with the general guide on protecting the ET 200iSP from
overvoltage.
Complete protection from overvoltage is only guaranteed when the entire system design is
based on the lightning protection zone concept. Comprehensive consideration must be given
to this when planning construction of facilities.
We therefore recommend that you contact your Siemens representative or a company
specialized in lightning and overvoltage protection if you require more detailed information
about overvoltage.
In the following we refer to the overvoltage protection device using the normative
terminology, i.e., according to the degree of hazard expected, overvoltage suppressor for
pulse shape 8/20 μs and lightning current suppressor for pulse shape 10/350 μs.
Further references
The following information is based on the lightning protection zone concept described in IEC
IEC 62305-4 - "Protection against LEMP".
ET 200iSP
Operating Instructions, 01/2010, A5E00247483-04
363