Electrical Structure; Potential Levels - WAGO 750 Series Manual

System Features
– If there is a power supply infeed, above the individual connections
• On I/O modules of the 750 and 753 Series:
– Above the indicators
• On some I/O modules of the 750 Series:
– Above the individual connections

3.2 Electrical Structure

3.2.1 Potential Levels

The I/O system is divided internally into the following potential groups.
• System Level
This potential group encompasses all the system-side electronics and includes the sys-
tem supply and local bus signals among other things.
• Field Level
This potential group contains the field-side power supply and I/O signals. The node
structure can be divided into different sections with supply and segment modules. Dif-
ferent field potentials can be used in the individual sections.
• Fieldbus
This potential group contains the signals of the corresponding fieldbus interface. The
voltage and current levels depend on the fieldbus standard used.
• Functional Ground
To discharge EMC interference, the system power supply, the field power supply and
the I/O signal inputs and outputs are capacitively coupled within the module to the
functional ground via the DIN-rail contacts.
I/O modules with dangerously active voltages on the field level are safely isolated from
the system level. Functional isolation from the system level is provided for I/O modules
with SELV/PELV voltages on the field level.
You can find product-specific information on "Isolation" in the technical data of the corre-
sponding
Example Potential Groups/Isolation with Electrically Isolated Power Supply Infeed
24 System manual | Version: 3.3.1
& Product Manual.
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3
Figure 12: Illustration of the Various Potential Groups
Serie 750, 753
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