RIA15 Wiring
Endress+Hauser 25
The best results with regard to EMC are achieved in most cases with one-sided shielding on
the feed side (without capacitance termination at the field device). Operation in the event of
disturbance variables as per NAMUR NE21 is thus guaranteed.
NOTICE
If the shielding of the cable is grounded at more than one point in systems without
potential matching, power supply frequency equalizing currents can occur that damage
the signal cable or have a serious effect on signal transmission.
‣
In such cases the shielding of the signal cable is to be grounded on one side only, i.e. it
must not be connected to the ground terminal of the housing. The shield that is not
connected should be insulated!
5.6 Connecting to functional grounding
5.6.1 Panel-mounted device
For EMC reasons the functional grounding should always be connected. When the device is
used in explosion hazardous environment (with optional Ex approval) the connection is
obligatory.
A0018894
9 Functional grounding terminal on panel-mounted device
5.6.2 Field device
For EMC reasons the functional grounding should always be connected. When the device is
used in explosion hazardous environment (with optional Ex approval) the connection is
obligatory and the field housing must additionally be grounded via a grounding screw fitted
on the outside of the housing.
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