Grounding - Siemens SIMATIC NET SCALANCE W1788 Series Operating Instructions Manual

Connection

6.5 Grounding

NOTICE
UL approval only for use in buildings
Within the area of authority of the NEC and CEC, the SCALANCE W1788/W1748
devices and the antennas connected to them may only be used in a closed building. For
this reason, do not lead antennas into the outdoor area if you need to meet UL or CSA
requirements.
6.5 Grounding
EMC disturbances are diverted to ground via the functional ground. This ensures the
immunity of the data transmission.
The grounding screws are identified by the following symbol for the functional ground
.
Protective earth/functional ground
The connection of the reference potential surface with the protective earth system is
normally in the cabinet close to the power feed-in. This earth conducts fault currents to
ground safely and according to DIN/VDE 0100 is a protective earth to protect people,
animals and property from too high contact voltages.
Apart from the protective earth, there is functional grounding in the cabinet. According to
EN60204-1 (DIN/VDE 0113 T1) electrical circuits must be grounded. The chassis (0 V) is
grounded at one defined point. Here, once again the 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.
Position
Functional ground is established via a grounding screw on the bottom of the device.
On the top, the device has an additional, optional connector to the functional ground, see
Device views (Page 20).
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SCALANCE W1788-x / W1748-1
Operating Instructions, 03/2022, C79000-G8976-C484-05