KROHNE PTIFLEX 2200 FOUNDATION FIELDBUS - Manual (Page 6)

3
ELECTRICAL CONNECTIONS
6
OPTIFLEX 2200 C
www.krohne.com 09/2013 - 4002573201 - AD FF OPTIFLEX 2200 R01 en
3.1 Cable types
Electrical cable specifications agree with International Standard IEC 61158-2. Shielded cables
prevent malfunctions and give protection from electromagnetic interefence. We recommend
that you follow these specifications to get good system performance.
In non-hazardous locations, a maximum of 32 field devices can be connected to the network. For
more data, refer to the table that follows.
3.2 Shielding and grounding
• For optimum electromagnetic compatibility of systems it is extremely important that the
system components, and particularly the bus cables connecting the components, are
shielded and that such shields - if possible - form an unbroken cover.
• Hence, it follows that, for use in non-hazardous duty systems, the cable shield should be
grounded as often as possible.
• In Ex systems an adequate equipotential bonding in the hazardous and non-hazardous
location along the entire Fieldbus installation is strongly recommended. Multiple grounding
of the shield is of advantage.
• In explosion-proof systems the shielding must at least be connected at one end of the cable.
• NAMUR NE 21 compliance is given, provided the above recommended cable types are used.
Core cross-section 0.8 mm² or
AWG 18
0.32 mm² or
AWG 22
0.13 mm² or
AWG 26
1.25 mm² or
AWG 16
Cable type A A A A B B B B C C C C D D D D
twisted pair,
individually
shielded
individual or
multiple twisted
pairs with overall
shield
multiple twisted
pairs, without
shielding
multiple non-
twisted cables,
without shielding
Max. length
incl. branch line
1900 m / 6200 ft 1200 m / 3900 ft 400 m / 1300 ft 200 m / 650 ft
Number of devices on
the bus segment
Electrical cable length on the spur
1 device 2 devices 3 devices 4 devices
25...32 1 m / 3.3 ft 1 m / 3.3 ft 1 m / 3.3 ft 1 m / 3.3 ft
19...24 30 m / 100 ft 1 m / 3.3 ft 1 m / 3.3 ft 1 m / 3.3 ft
15...18 60 m / 200 ft 30 m / 100 ft 1 m / 3.3 ft 1 m / 3.3 ft
13...14 90 m / 300 ft 60 m / 200 ft 30 m / 100 ft 1 m / 3.3 ft
1..12 120 m / 400 ft 90 m / 300 ft 60 m / 200 ft 30 m / 100 ft
INFORMATION!
Electrical cable length decreases if the number of devices on the branch line increases.
A terminator must be connected at the two ends of each bus segment.
INFORMATION!
The use of twisted and shielded cables is strongly recommended, otherwise EMC protection of
the signal converter cannot be assured.