Functional Ground - Siemens SIMATIC NET SCALANCE XR-300WG Operating Instructions Manual

6.8

Functional ground

Grounding options
Grounding (functional grounding) takes place via the mounting bracket on the device or via the
grounding screw at the front of the device.
Figure 6-7
With 240 VAC variants the device is grounded via the power cable.
Functional ground
EMC disturbances are diverted to ground via the functional ground. This ensures the immunity
of the data transmission.
According to EN60204-1 (DIN/VDE 0113 T1) electrical circuits must be grounded. The chassis (0
V) is grounded at one defined point. Grounding is implemented with the lowest leakage
resistance to ground in the vicinity of the power feed-in.
With automation components, functional ground also ensures interference-free operation of a
controller. Via the functional ground, interference currents coupled in via the connecting cables
are discharged to ground.
Connect functional grounding via a grounding screw
The functional ground must be implemented with low impedance. The connection of the
functional ground must be established directly on the mounting plate or the DIN rail terminal.
To connect the functional ground, use a copper cable of category 20 AWG or a cable with a cross-
section ≥ 0.75 mm
①
②
SCALANCE XR-300WG
Operating Instructions, 03/2021, C79000-G8976-C454-07
Position of the grounding screw on the front of the device.
.
2
Grounding terminal with cable
Grounding screw with spring washer and washer
Connecting up
6.8 Functional ground
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