User Documentation

Planning
2053260000/05/2015
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Since the protective earth is part of the general electrical system, it will not
be described in any more detail in this document. However, the applicable
regulations are to be observed in each case!
Note
Some PROFINET devices also have a connection for the protective
earth. In particular, these are PROFINET devices that have an additional
power supply with a higher voltage. Connect the protective earth in
accordance with the applicable regulations.
2.9.2 Functional earthing
The functional earth is used to discharge EMC interference to earth. This
increases the interference immunity of the data transmission. The functional earth
is used to earth the cable shields and housing of devices in order to discharge
interference to earth.
Manufacturer's instructions
Read the manufacturer's documentation. The manufacturer information
gives you details about how you need to connect the PROFINET nodes
in terms of earthing and equipotential bonding
Some PROFINET devices have a connection terminal for the functional earth.
The connection terminal is marked with the symbol for the functional earth.
To connect the connection terminal of the PROFINET devices to the functional
earth of the system, use a cable that has the shortest possible length and a large
cross-section. In many cases the entire metallic structure of the system is used
as functional earth. With other devices, the functional earth is implemented by
means of the installation fastening. Therefore, also connect the system's top-hat
rails to the functional earth.