Rosemount 8732 Series, Reference Manual

Page: 20 / 190

Reference Manual
00809-0100-4663, Rev BA
January 2010
Rosemount 8732
2-8
Figure 2-5. AC Transmitter
Power Connections
Connect F
OUNDATION
fieldbus Wiring
The F
OUNDATION
fieldbus signal provides the output information from the
transmitter.
Transmitter
Communication Input
The F
OUNDATION
fieldbus communication requires a minimum of
9 V dc and a maximum of 32 V dc at the transmitter communication terminals.
NOTES
• Do not exceed 32 V dc at the transmitter communication terminals.
• Do not apply ac line voltage to the transmitter
communication terminals.
Improper supply voltage can damage the transmitter.
Power Conditioning
Each fieldbus power supply requires a power conditioner to decouple the
power supply output from the fieldbus wiring segment.
Field Wiring
Power independent of the coil power supply must be supplied for F
OUNDATION
fieldbus communications. Use shielded, twisted pair for best results. For new
installations or to get maximum performance, twisted pair cable designed
especially for fieldbus should be used. Table 2-1 details cable characteristics
and ideal specifications.
Table 2-1.
Ideal Cable Specifications for
Fieldbus Wiring
AC Line or DC +
Transmitter
Power Cable
AC Neutral or DC –
AC or DC
Ground
See “Safety Messages” on page 2-1 for complete warning information.
Characteristic Ideal Specification
Impedance 100 Ohms ± 20% at 31.25 kHz
Wire Size 18 AWG (0,8 mm
2
)
Shield Coverage 90%
Attenuation 3 db/km
Capacitive Unbalance 2 nF/km