Wiring; Profibus Pa Cable Specifications - Endress+Hauser FEL 50 A Operating Instructions Manual

Liquiphant M/S (HT), FEL 50 A PROFIBUS PA
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Endress+Hauser
4

Wiring

Warning!
• When connecting Ex-certified devices, see the notes and wiring diagrams in the
Ex-specific supplement to these Operating Instructions. Please do not hesitate to
contact your E+H representative if you have any questions.
4.1

PROFIBUS PA Cable specifications

Always use a twisted, screened two-wire cable. When installing in the hazardous area,
keep to the following characteristic values (EN 50020, FISCO model):
Cable structure
Wire size
Loop resistance
(DC)
Impedance at 31.25 kHz
Attenuation constant
at 39 kHz
Capacitive asymmetry
Envelope delay distortion
(7.9 through 39 kHz)
Shield coverage
Maximum Cable length
(incl. spurs > 1 m)
* not specified
The following cable types are suitable, for example:
Non-Ex area:
• Siemens 6XV1 830-5BH10 (grey)
• Kerpen CEL-PE/OSCR/PVC/FRLA FB-02YS(ST)YFL (grey)
• Belden 3076F (orange)
Ex area:
• Siemens 6XV1 830-5AH10 (blue)
• Kerpen CEL-PE/OSCR/PVC/FRLA FB-02YS(ST+C)YFL (blue)
Maximum overall cable length
The maximum network expansion depends on the type of explosion protection and the
cable specifications. The overall cable length is made up of the length of the main cable
and the length of all spurs (> 1 m). Note the following points:
• The highest permissible cable length is dependent on the cable type used:
Type A 1900 m
Type B 1200 m
Type A
twisted pair,
screened
2
0.8 mm
(AWG 18)
44 Ω/km
100 Ω ± 20%
3 dB/km
2 nF/km
1.7 µs/km
90%
1900 m
4 Wiring
Type B
one or more twisted pairs,
fully shielded
2
0.32 mm
(AWG 22)
112 Ω/km
100 Ω ± 30%
5 dB/km
2 nF/km
*
*
1200 m
9