Siemens SIMATIC ET 200AL System Manual page 70

Connecting
8.5 Connecting ET 200AL to functional earth
The figure below shows a configuration with a new voltage infeed for the modules. The
different potential groups have a gray background.
Figure 8-5 Wiring of the power supply
Reference
You will find additional information on electrical configuration and the voltage drop in the
section Connecting cables for ET 200AL (Page 74).
8.5 Connecting ET 200AL to functional earth
Introduction
You must connect the distributed I/O system ET 200AL to functional earth (FE)
What is functional earth?
All ET 200AL modules feature a functional earth connection. This connection is used to
suppress interference sensitivity, but not for protection purposes. With the functional earth
connection, you create an electrical connection directly to a point of your system or shielding.
This discharges the EMC interference directly into the earth. By discharging the EMC
interference, the interference safety of the entire module is increased.
The figure below shows the symbol with which the functional earth connection is identified
on the ET 200AL modules.
Figure 8-6 Functional earth
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Distributed I/O system
System Manual, 12/2023, A5E31861578-AL