Emerson 7003M - Manual (Page 24)

Operator Manual
748223-K
June 2002
2-6 Installation Rosemount Analytical Inc. A Division of Emerson Process Management
Model 7003M
CAUTION
TOTAL OUTPUT RESISTANCE
Total resistance of all output devices and
associated interconnection cable must not
exceed 600 ohms.
c. Current Output Connections
Refer to Figure 2-4 on page 2-7. Isolated
current output (0 to 20 or 4 to 20 mA) is
standard on the Model 7003M. To
convert from current output to voltage
output, see Section 2-5d below.
1. Disconnect power to the analyzer.
Remove rear cover.
2. Connect the shielded recorder cable
leads to the rear panel of the analyzer
(Figure 2-2 on page 2-3):
TB3-7 has no connection
TB3-8 negative (-)
TB3-9 positive (+)
3. Connect the other end of the output
cable to terminals of the output
device. Ensure that polarity is
correct. Connect the shield to a
suitable ground point.
NOTE:
Current output terminals are not
grounded. Ground the current loop at
some point within the circuit to mini-
mize noise or other undesirable inter-
actions.
4. Replace the rear cover. Do not
overtighten cover retaining screws, to
avoid stripping the threads in the
plastic case.
5. To connect recorder(s), see Figure
2-4 on page 2-7.
d. Voltage Output Connections
Refer to Figure 2-4 on page 2-7. To
convert the voltage output to current
output see Section 0 above.
To monitor the signal output with a
voltage recorder or other voltage device,
the standard current output must be
converted into a voltage by connecting a
resistor in parallel with the output device
as follows:
1. Determine the resistor value (R)
required:
R
1
ohms = (fullscale voltage,
volts)/(0.02 amps)
2. Disconnect power; remove the rear
cover.
3. Connect resistor (1/4 watt or greater)
of value R between TB3-8 and TB3-9
(Figure 2-4 on page 2-7).
4. Connect leads of a shielded recorder
cable to the rear panel of the analyzer
(Figure 2-2 on page 2-3):
TB3-7 has no connection
TB3-8 negative (-)
TB3-9 positive (+)
5. Connect other end of output cable to
terminals of output device. Ensure
that polarity is correct.
6. Replace the rear cover. Do not
overtighten cover retaining screws, to
avoid stripping the threads in the
plastic case.
7. For the low end point to be 0 volts, set
the current output range to 0 to 20mA
when setting up the instrument
(Section 3-5b on page 3-13).