Cable Types; Shielding And Grounding - Honeywell TWM 9000 Supplementary Instructions Manual

ELECTRICAL CONNECTIONS
3

3.4 Cable types

The cable types are specified according to IEC 61158-2. Shielded cables offer the advantage of
malfunction-free operation with adequate protection against electromagnetic influences, and
make it possible to employ the full performance of the Foundation Fieldbus system.
Core cross-section
Cable type
Max. length
incl. branch line
Table 3-1: Specification of cable types
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.
Number of devices
25...32
19...24
15...18
13...14
1..12
Table 3-2: Cable lengths for number of devices per branch line
All bus segments must be fitted with a terminator at both ends.

3.5 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.
INFORMATION!
The use of twisted and shielded cables is strongly recommended, otherwise EMC protection of
the signal converter cannot be assured.
8
2
0.8 mm or 0.32 mm
AWG 18 AWG 22
A A A A B B B B
twisted pair, individual or
individually multiple twisted
shielded pairs with overall
shield
1900 m / 6200 ft 1200 m / 3900 ft
Cable lengths for number of devices per branch line
1 device 2 devices
1 m / 3.3 ft
30 m / 100 ft
60 m / 200 ft 30 m / 100 ft
90 m / 300 ft 60 m / 200 ft
120 m / 400 ft 90 m / 300 ft
www.honeywellprocess.com
2 2
or 0.13 mm or
AWG 26
C C C C
multiple twisted
pairs, without
shielding
400 m / 1300 ft
3 devices
1 m / 3.3 ft 1 m / 3.3 ft
1 m / 3.3 ft 1 m / 3.3 ft
1 m / 3.3 ft
30 m / 100 ft
60 m / 200 ft
TWM 9000
2
1.25 mm or
AWG 16
D D D D
multiple non-
twisted cables,
without shielding
200 m / 650 ft
4 devices
1 m / 3.3 ft
1 m / 3.3 ft
1 m / 3.3 ft
1 m / 3.3 ft
30 m / 100 ft
34-VF-25-37 iss.2 GLO Jan 18 US