Endress+Hauser Proline Promass E 200, Краткое руководство по эксплуатации

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Proline Promass E 200 Electrical connection
Hauser 25
7.1.5 Shielding and grounding
Optimum electromagnetic compatibility (EMC) of the fieldbus system can only be guaranteed
if the system components and, in particular, the lines are shielded and the shield forms as
complete a cover as possible. A shield coverage of 90% is ideal.
• To ensure an optimum EMC protective effect, connect the shield as often as possible to the
reference ground.
• For reasons of explosion protection, you should refrain from grounding however.
To comply with both requirements, the fieldbus system allows three different types of
shielding:
• Shielding at both ends.
• Shielding at one end on the feed side with capacitance termination at the field device.
• Shielding at one end on the feed side.
Experience shows that the best results with regard to EMC are achieved in most cases in
installations with one-sided shielding on the feed side (without capacitance termination at
the field device). Appropriate measures with regard to input wiring must be taken to allow
unrestricted operation when EMC interference is present. These measures have been taken
into account for this device. Operation in the event of disturbance variables as per NAMUR
NE21 is thus guaranteed.
Where applicable, national installation regulations and guidelines must be observed during
the installation!
Where there are large differences in potential between the individual grounding points, only
one point of the shielding is connected directly with the reference ground. In systems without
potential equalization, therefore, cable shielding of fieldbus systems should only be grounded
on one side, for example at the fieldbus supply unit or at safety barriers.