Flowserve 3400IQ Digital Positioner - Manual (Page 20)

Logix 3400IQ Digital Positioner FCD LGENIM3401-00 – 06/06
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Figure 6: Field Termination
Shielded Cable
FF Signal
Connect Shield at Source
Housing EARTH
Terminal
External
Bonding
Location
FF Field
Terminators
Environmental
Seal
c WARNING: The green grounding screw must not be used to terminate signal shield wires.
6.3 Segment Compliance Voltage
(See Figure 7)
Output compliance voltage refers to the voltage limit that can be provided by the FF source. A FF
system consists of the FF source, wiring resistance, barrier resistance (if present), and the Logix
3400IQ positioner voltage. The Logix 3400IQ digital positioner requires that the system allows for a
9.0 VDC drop across the positioner at minimum segment voltage. The actual voltage at the terminals
varies from 9.0 to 32.0 VDC depending on the FF signal and ambient temperature.
Determine if the segment will support the Logix 3400IQ digital positioner by performing the following
calculation.
Voltage = Compliance Voltage (@ 23 mA) –
23 mA • (R
barrier
+ R
wire
)
Equation 1