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The Nonincendive Field Wiring concept allows the interconnection of nonincendive field
wiring apparatus using any of the wiring methods permitted for unclassified locations.
Vmax >= Voc or Vt, Ca >= Ci +Ccable, La >= Li + Lcable"
The Nonincendive Field Wiring concept allows the interconnection of FM-approved
nonincendive devices with FNICO parameters not specifically examined in combination as a
system when: Uo or Voc or Vt <= Vmax, Po <= Pi
In each I.S. Fieldbus segment only one active source, normally the associated apparatus, is
allowed to provide the necessary power for the Fieldbus system. The allowed voltage (Uo,
Voc, Vt) of the associated apparatus used to supply the bus must be limited to the range of
14V d.c. to 24V d.c. All other equipment connected to the bus cable has to be passive,
meaning that the apparatus is not allowed to provide energy to the system, except to a
leakage current of 50 PA for each connected device. Separately powered equipment needs a
galvanic isolation to insure that the intrinsically safe Fieldbus circuit remains passive.
The cable used to interconnect the devices needs to comply with the following parameters:
Loop resistance R': 15 ...150 :/Km
Inductance per unit length L': 0.4...1mH/km
Capacitance per unit length C': 80 ...200 nF/km
C' = C' line/line + 0.5 C' line/screen, if both lines are floating
or
C'= C' line/line + C' line/screen, if the screen is connected to one line
Length of spur Cable: max. 30 m
Length of trunk cable: max. 1 Km
Length of splice: max. 1 m
Terminators
At each end of the trunk cable an approved line terminator with the following parameters is
suitable:
R = 90 ...100 :
C = 0 ...2.2 PF.
System evaluation
The number of passive devices like transmitters, actuators, connected to a single bus
segment is not limited due to I.S. or N.I. reasons. Furthermore, if the above rules are
respected, the inductance and capacitance of the cable need not to be considered and will
not impair the intrinsic safety or nonincendive safety of the installation as applicable.
The sensor circuit is not infallibly galvanically isolated from the Fieldbus input circuit.
However, the galvanic isolation between the circuits is capable of withstanding a test
voltage of 500 Vac during 1 minute.
5350QE01.doc
2005-03-16
Rev. AC
70
All manuals and user guides at all-guides.com
5/7
5350QE01.doc
Nonincendive Field Wiring Concept:
The Nonincendive Field Wiring concept allows for the interconnection of nonincendive field
wiring apparatus using any of the wiring methods permitted for unclassified locations.
Vmax >= Voc or Vt, Ca >= Ci +Ccable, La >= Li + Lcable"
Installation Notes For FISCO and Entity Concepts:
1.
The Intrinsic Safety Entity concept allows the interconnection of FM / UL / CSA-
approved intrinsically safe devices (Div. 1 or Zone 0 or Zone1), with entity parameters
not specifically examined in combination as a system when: Uo or Voc or Vt d Vmax,
Io or Isc or It d Imax, Po d Pi.
Ca or Co t 6Ci + 6Ccable, La or Lo t 6Li + 6Lcable, Po d Pi.
2.
The Intrinsic Safety FISCO concept allows the interconnection of FM / UL / CSA-
approved intrinsically safe devices with FISCO parameters not specifically examined in
combination as a system when:
Uo or Voc or Vt d Vmax, Io or Isc or It d Imax, Po d Pi.
3.
Control equipment connected to the Associated Apparatus must not use or generate
more than 250 Vrms or Vdc.
4.
Intrinsically Safe Installation should be in accordance with ANSI/ISA RP12.6.01
(except chapter 5 for FISCO Installations) "Installation of Intrinsically Safe Systems for
Hazardous (Classified) Locations" and the National Electrical Code® (ANSI/NFPA 70)
Sections 504 and 505.
5.
The configuration of associated Apparatus must be FM Approvals or UL / CSA
Approved under the associated concept.
6.
Associated Apparatus manufacturer's installation drawing must be followed when
installing this equipment.
7.
The 5350B is approved for Class I, Zone 0, applications. If connecting AEx[ib]
associated Apparatus or AEx ib I.S. Apparatus to the 5350B the I.S. circuit is only
suitable for Class I, Zone 1, or Class I, Zone 2, and is not suitable for Class I, Zone 0
or Class I, Division 1, Hazardous (Classified) Locations".
8.
No revision to drawing without prior FM / UL / CSA Approval.
9.
Simple Apparatus is defined as a device that neither generates nor stores more than
1.5 V, 0.1 A or 25 mW.
10.
The termination must be NRTL-approved, and the resistor must be infallible.
11.
Warning:
For applications in Div. 2 or Zone 2 (Classified Locations) Explosion hazard: Except for
nonincendive field circuits, do not disconnect the apparatus unless the area is known
to be non hazardous.
12.
Warning:
Substitution of Components May Impair Safety.
2005-03-16
Rev. AC
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