Endress+Hauser PROline Prosonic Flow 93 Serie Fiche Technique page 44

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Potential equalisation with shielding grounded at both ends
3.1
R
C
3.2
+5 V
390 Ω
220 Ω
390 Ω
GND
Fig. 8: Examples for connection of potential matching cables
1 = distributor/T-box
2 = Prosonic Flow 93 bus devices for hazardous area
3.1 = bus termination for PROFIBUS-PA: R = 90...100 Ω , C = 0...2.2 µ F
3.2 = bus termination for PROFIBUS-DP
4 = bus power supply or process control system variant 4a
4a = shielding connected via capacitor
5 = bus power supply or process control system variant 5a
5a = potential equalisation line led out
Variant 4/4a:
With capacitive grounding of the shielding in the safe area the potential equalisation line
does not need to be led out of the safe area.
Use small capacitors (e.g. 1 nF, 1500 V dielectric strength, ceramic).
The total capacitance connected at the shielding may not exceed 10 nF.
Variant 5/5a:
Potential equalisation line is led out of the safe area.
PROline Prosonic Flow 93 PROFIBUS-DP/-PA
1 1
r
Esc
- + E
2
E X E X
4a
r
Esc
- +
E
2
5a
Endress+Hauser
4
5