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Reference Manual
300560EN, Rev AA
May 2011
3-7
Rosemount 2230
Section 3. Installation
Grounding - F
OUNDATION™ Fieldbus
Signal wiring of the fieldbus segment must not be grounded. Grounding one
of the signal wires will shut down the entire fieldbus segment.
Shield Wire Connection
To protect the fieldbus segment from noise, grounding techniques for shield
wire usually require a single grounding point for shield wire to avoid creating a
ground loop. The ground point is typically at the power supply (Rosemount
2410 Tank Hub).
The Raptor devices are designed for “daisy-chain” connection of shield wiring
in order to enable a continuous shield throughout the Tankbus network. The
shield wire terminal in the 2230 is not connected to ground. It only provides
electrical continuity to daisy-chained Tankbus cables.
3.3.3 Cable Selection
for the Tankbus
Use shielded twisted pair wiring for the Rosemount 2230 in order to comply
with FISCO
(1)
requirements and EMC regulations. The cables must be
approved for use in hazardous areas, where applicable. In the U.S.
explosion-proof conduits may be used in the vicinity of the vessel.
We recommend cable size 0.75 mm
2
(18 AWG) in order to facilitate wiring.
However, cables within the range 22 AWG to 16 AWG (0.5 t o1.5 mm²)
in
order to minimize the voltage drop to the 2230 display.
Tankbus cabling must be approved for use in minimum 85°C to match
requirements for all devices in a Raptor system.
The FISCO specification requires that cables for the Tankbus comply with the
following parameters:
Table 3-1. FISCO cable
parameters
3.3.4 Hazardous Areas When the Rosemount 2230 is installed in a hazardous area, national and
local regulations and specifications in applicable certificates must be
observed, see Appendix B: Product Certifications.
3.3.5 Power
Requirements
The Rosemount 2230 is powered over the intrinsically safe Tankbus by the
Rosemount 2410 Tank Hub. The 2410 feeds the intrinsically safe fieldbus
segment by acting as a FISCO power supply on the Tankbus (9 - 17.5 Vdc,
polarity insensitive).
See the Rosemount 2410 Reference Manual (Document no. 305030EN) for
more information.
(1) See IEC 61158-2 and IEC/TS 60079-27:2002.
Parameter Value
Loop resistance 15/km to 150/km
Loop inductance 0.4 mH/km to 1 mH/km
Capacitance 45 nF/km to 200 nF/km
Maximum length of each spur cable 60 m in apparatus class IIC and IIB
Maximum length of each trunk cable 1000 m in apparatus class IIC and 1900 m in
apparatus class IIB