Power repeater / power supply according to IEC 61158-2
FOUNDATION FieldbusGeneral
Subject to reasonable modifications due to technical advances.
Copyright Fuchs, Printed in Germany
Fuchs Group • Tel.: Germany (06 21) 7 76-0 • USA (330) 4 25 35 55 • Singapore 7 79 90 91 • Internet http://www.pepperl-fuchs.com
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For more information on the topic of explosion protection through intrinsic safety,
please refer to the Fuchs manual on explosion protection Part. No. 21417 or
the video Explosion Protection of Electrical Systems:
5.1.1
Dimensioning of a field bus segment in accordance with IEC 61158-2
A power repeater opens a new PROFIBUS PA or H1 bus segment. The following sec-
tion illustrates how a field bus segment of this type should be dimensioned.
The following section assumes that a cable with the following characteristic values is
in use:
The cable parameters that are specified are cable type A of the PROFIBUS PA Com-
Modulation cur-
rent
on field side
+10 mA
+10 mA
+10 mA
+10 mA
max. number of
field bus instru-
ments
a
6
10
21
32
max. line length
b
1000 m
1000 m
1900 m
1900 m
min. line length
c
519 m
860 m
348 m
852 m
a.The actual number of field devices on a bus segment depends on the actual current consumption of the slaves. The specified number of field devices is only reached if
the current consumption for each station is 10 mA.
b.The actual line length depends among other things on the cable that is used and the number and distribution of slaves.
c.For max. output current and cable type A [0.8 mm² (18 AWG)]
If a Power Repeater with an intrinsically safe interface is used, the
requirements of EN 50020 "Explosion Protection through Intrinsic
Safety“ and the PTB report PTB-W-53 (FISCO model) or the Entity
model must be observed.
Power repeater KLD2-PR-Ex1.IEC is certified according to Entity and
FISCO modelThe KLD2-PR-Ex1.IEC1 power repeater is certified
according to the FISCO model field devices that are certified for the
Entity model must not be connected to the KLD2-PR-Ex1.IEC1.
Cable structure
twisted wire pair, shielded
Conductor cross-section (nominal)
0.8 mm² (AWG 18)
Loop resistor (direct current)
44
Ω
/km
Wave resistance at 31.25 kHz
100
Ω
+ 20 %
Wave attenuation at 39 kHz
3 dB/km
Capacitive asymmetry
2 nF/km
Group runtime distortion (7.9 ... 39) kHz
1.7 µs
Covering level of the shield
90%
KLD2-PR(2)-
Ex1.IEC
KLD2-PR(2)-
Ex1.IEC1
KLD2-PR-
NI1.IEC
KLD2-PR-
1.IEC
