Emerson Rosemount 5900, Reference Manual

Page: 64 / 100

Reference Manual
300520EN, Rev AA
November 2009
Rosemount 5900 Series
3-40
Section 3. Installation
3.4.3 Cable Selection
Use shielded twisted pair wiring for the Rosemount 5900 Series in order to
comply with EMC regulations and to ensure good fieldbus performance is
achieved. The cables must be suitable for the supply voltage and approved
for use in hazardous areas, where applicable. In the U.S. explosion-proof
conduits may be used in the vicinity of the vessel.
Use 22 AWG to 18 AWG in order to minimize the voltage drop to the
transmitter.
The FISCO
(1)
F
OUNDATION
™ fieldbus specification requires that cables for the
Raptor Tankbus comply with the following parameters:
Table 3-5. FISCO cable
parameters
3.4.4 Hazardous Areas
When the Rosemount 5900 level gaugeis installed in hazardous area, local
regulations and specifications in applicable certificates must be observed.
3.4.5 Power
Requirements
The Rosemount 5900 is powered over the intrinsically safe Tankbus by the
Rosemount 2410 tank communication unit. The 2410 feeds the intrinsically
safe fieldbus segment by acting as a FISCO power supply on the Tankbus.
3.4.6 Power Budget
The Rosemount 2410 tank hub delivers 250 mA to the Tankbus. The number
of tanks served by the 2410 depends on the type of connected field devices
and their power consumption
(2)
. Power consumption per field device is listed
in Table 3-6 below:
Table 3-6. Power consumption
for various Raptor devices
The Rosemount 2410 tank hub supports a maximum of one tank for a
5900S-based configuration. In a 5300T- or 5400T-based configuration up to
10 tanks are supported.
(1) See also the reference document IEC/TS 60079-27
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 cable length including trunk and
spurs 1000 m in apparatus class IIC and 1900 m in
apparatus class IIB
(2) May be fewer than the 16 devices per segment, stated in the F
OUNDATION
™ fieldbus stan-
dard.
Field device Power consumption
5900S Radar Level Gauge
50 mA
5300T or 5400T Series Radar Level
Gauge 20-25 mA
Rosemount 2230 Graphical Field
Display 25 mA
Rosemount 2240S Multi-input
Temperature Transmitter 30 mA including MST and WLS
Rosemount 644 Temperature
Transmitter 11 mA
Rosemount 3051 Pressure
Transmitter 17.5 mA
Preliminary