GE DigitalFlow GS868, Руководство для стартапов

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Installation 1-15
March 2008
Wiring a 0/4-20 mA
Analog Inputs Option Card
To calculate the standard mass flow rates of the steam, the Model
GS868 requires accurate
temperature and pressure data from the
measurement site. Transmitters installed in the flowcell can provide
this information via an optional 0/4-20 mA analog inputs card. This
option card includes two isolated 0/4-20 mA analog inputs
(designated as A and B), each of which includes a 24 VDC power
supply for loop-powered transmitters. Either input may be used to
process the temperature signal, while the other input is used to
process the pressure signal.
Note:
To enter programming data during operation of the meter, it
will be necessary to know which input is assigned to which
process parameter. This information should have been entered
in Appendix B,
Data Records .
The analog inputs, which have an impedance of 118 ohms, should be
connected with standard twisted-pair wiring. Power to the
transmitters may be supplied either by the integral 24 VDC power
supply on the analog input card or by an external power supply.
Figure 1-7 below shows typical wiring diagrams, with and without an
external power supply, for one of the analog inputs.
Figure 1-7: Analog Input Wiring Diagram
+24V 1
INHI 2
INLO 3
+ –
+ IN
– OUT
+ IN
– OUT
Sensor
Sensor
Transmitter
Transmitter
Analog Input
Analog Input
24 VDC
POWER SUPPLY
With External Power Supply
With Internal Power Supply
RTN 4
Jumper
+24V 1
INHI 2
INLO 3
RTN 4