Cable shielding
Designing interference-free controllers
16
Function Manual, 06/2014, A5E03461486-AB
Shield connection with capacitive grounding at one end
If you do not have the option of installing equipotential bonding (in plants covering a large
area, for example), connect capacitive grounding to one end of your shield. In this case, only
high-frequency interference will be reduced.
The following figure shows the capacitive grounding of a cable shield. The values indicated
in the figure are indicative and will differ from system to system. The capacity diverts the
high-frequency interference. This capacity provides high-impedance protection for the power
frequency (50 or 60 Hz), thus preventing equalizing currents via the shield. A parallel
switched high-impedance resistance prevents the capacity from loading a direct current.
Figure 4-1
Capacitive grounding of the shield
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