Endress+Hauser Proline Promass E 500 - Device Plug Pin Assignment; Shielding and Grounding

Proline Promass E 500 PROFIBUS PA Electrical connection
Endress+Hauser 41
7.2.5 device plug pin assignment
1
2
4
3
Pin Assignment Coding Plug/socket
1 + PROFIBUS PA + A Plug
2 Grounding
3 - PROFIBUS PA –
4 Not assigned
7.2.6 Shielding and grounding
Optimal electromagnetic compatibility (EMC) of the fieldbus system can be guaranteed
only 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.
1. To ensure optimal EMC protection, connect the shield to the reference ground as
often as possible.
2. For reasons concerning explosion protection, it is recommended that grounding be
dispensed with.
To comply with both requirements, there are basically three different types of shielding in
the fieldbus system:
• 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.
1. Observe national installation requirements and guidelines during installation.
2. Where there are large differences in potential between the individual grounding
points,
connect only one point of the shielding directly to the reference ground.
3. In systems without potential equalization,
the cable shielding of fieldbus systems should be grounded on one side only, for
example at the fieldbus supply unit or at safety barriers.
NOTICE
In systems without potential matching, the multiple grounding of the cable shield
causes mains frequency equalizing currents!
Damage to the bus cable shield.
‣
Only ground the bus cable shield to either the local ground or the protective ground at
one end.
‣
Insulate the shield that is not connected.