Emerson Rosemount 751 User manual

Quick Start Guide
00825-0100-4378, Rev AD
June 2016
Rosemount™751 Field Signal Indicator
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June 2016
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Quick Start Guide
This guide provides basic guidelines for Rosemount 751 Remote Indicator. It does not provide
instructions for configuration, diagnostics, maintenance, service, troubleshooting,
Explosionproof, Flameproof, or intrinsically safe (I.S.) installations. Refer to the Rosemount 751
Reference Manual (document number 00809-0100-4378) for more instruction. This manual is
also available electronically on www.rosemount.com.
Explosions could result in death or serious injury.
Installation of this indicator in an explosive environment must be in accordance with the
appropriate local, national, and international standards, codes, and practices. Review the
approvals section of the Rosemount 751 Reference Manual for any restrictions associated with
a safe installation.
In an Explosionproof/Flameproof installation, do not remove the indicator cover when power
is applied to the unit.
Electrical shock can result in death or serious injury.
Avoid contact with the leads and terminals. High voltage that may be present on leads can
cause electrical shock.
Contents
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 9
Product Certifications . . . . . . . . . . . . . . 11
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Installation
Assembly
The Rosemount 751 Field Signal Indicator is comprised of the components shown
in Figure 1. The housing may contain an analog or LCD display meter. Both meters
are independent of component parts and are completely interchangeable. Both
meters plug into the terminal screws on the housing, as shown in Figure 1.
The meter subassembly contains the components shown in Figure 2.
Figure 1. Rosemount 751 Exploded View
A. Terminal screws
B. Housing O-ring
C. Field wiring terminals
D. Loop protection diode
E. Tapped mounting boss
F. Optional mounting bracket
G. Mounting bolt with washer
H. U-bolt for 2-in. pipe
I. Housing
J. Optional ¾ to ½-in. conduit reducing bushing
(if required)
K. Meter
L. Bushing
M. Foam spacer
N. Housing cover
A
BC
DE
FG
H
I
J
K
L
M
N
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Quick Start Guide
Figure 2. Meter Exploded View
A. Retaining straps
B. Mounting screw into housing
C. Washer for retaining strap
D. Mounting screws into mounting plate
E. Terminal screws (2)
F. Mounting plate
G. Spacer plate
H. LCD display
I. Bushing
J. Foam spacer
K. Configuration buttons
A
B
C
D
K
J
I
H
G
F
E
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June 2016
Wiring diagrams
Use the following wiring diagrams to wire the Rosemount 751 Field Signal
Indicator, in series or in parallel, with Rosemount transmitters. Use shielded cable
for best results in electrically noisy environments.
It is recommended that the Rosemount 751 indicator be wired in a series
configuration when the 4-20 mA transmitter does not contain a test terminal. The
Rosemount 751 is designed so the analog or LCD display meter can be removed
from the housing without impacting the integrity of the 4-20 mA loop. Removal
of the entire Rosemount 751 device from the series configuration will disrupt the
loop.
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Quick Start Guide
Figure 3. Rosemount 751 Series Wiring Diagrams
Rosemount 3144P Temperature Transmitters and Rosemount 2051,
3051C, or 3051S Pressure Transmitters
A. Power supply
B. Load resistor
C. Optional ground
A
A
751
4–20 dc Input Signal for
Rosemount 2051
4–20 mA dc Input Signal for
Rosemount 3144P
+
+
–
–
C
B
T
2051
+
–
+
–
3144P C
B
–
+
T
751
+
–
A
A
4–20 dc Input Signal for
Rosemount 3051S
4–20 mA dc Input Signal for
Rosemount 3051C
+
+
–
–
C
B
T
3051C
751
+
–
+
+
–
–
C
B
T
3051S
751
+
–
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It is recommended that the Rosemount 751 indicator be wired in a parallel
configuration when the 4-20 mA transmitter includes a test terminal. Utilization
of the test terminal is required in a parallel configuration. Connecting the 751
indicator across the positive and negative terminals of the 4-20 mA transmitter
could impact the loop.
A parallel configuration will allow the removal of the 751 indicator without
affecting the integrity of the 4-20 mA loop. Additionally, spare 751 indicators can
be added without disrupting the loop.
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Quick Start Guide
Figure 4. Rosemount 751 Parallel Wiring Diagrams
A. Power supply
B. Load resistor
C. Optional ground
Parallel Wiring Diagrams for Rosemount 3144P Temperature Transmitter
and Rosemount 2051, 3051C or 3051S Pressure Transmitters
A
A
751
4–20 dc Input Signal for
Rosemount 2051
4–20 mA dc Input Signal for
Rosemount 3144P
+
+
–
–
C
B
T
2051
+
–
+
–
3144P
C
B
–
+
T
751
+
–
A
A
4–20 dc Input Signal for
Rosemount 3051S
4–20 mA dc Input Signal for
Rosemount 3051C
+
+
–
–
C
B
T
3051C
751
+
–
+
+
–
–
C
B
T
3051S
751
+
–
3051C
4–20 mA dc Input Signal for
Rosemount 3051C
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Configuration
LCD display configuration
The 20-segment bar graph is factory calibrated and represents 4–20 mA directly,
but the end points of the LCD display are user-definable. The meter requires a
current between 4 and 20 mA in order to be scaled, but the actual value of the
current is not significant.
Remove the cover
1. Unscrew and remove the transparent housing cover from the LCD display
body.
Position the decimal point and select the meter function
1. Press the left and right configuration buttons simultaneously and release them
immediately.
2. To move the decimal point to the desired location, press the left configuration
button.
Note
The decimal point wraps around.
3. To scroll through the mode options, press the right configuration button
repeatedly until the meter displays the desired mode (See Table 1).
Note
The LCD display time-out is approximately 16 seconds. If you do not press the configuration
buttons within 16 seconds, the indicator will revert to reading the current signal.
Explosions can result in death or serious injury. Do not remove the instrument cover in
explosive environments when the circuit is alive.
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Store the information
1. Press both configuration buttons simultaneously for two seconds.
Note
The meter displays “- -” for approximately 7.5 seconds while the information is being stored.
Set the display equivalent to a 4 mA signal
1. Press the left configuration button for two seconds.
2. To decrease the display numbers, press the left configuration button. To
increase the numbers, press the right configuration button. Set the numbers
between –999 and 1000.
3. To store the information, simultaneously press both configuration buttons for
two seconds.
Set the display equivalent to a 20 mA signal
1. Press the right configuration button for two seconds.
2. To decrease the display numbers, press the left configuration button. To
increase the numbers, press the right configuration button. Set the numbers
between –999 and 9999.
Note
The sum of the 4 mA point and the span must not exceed 9999.
3. To store the information, simultaneously press both configuration buttons for
two seconds. The LCD display meter is now configured.
Replace the cover
1. Make sure the rubber gasket is seated properly, and thread the transparent
housing cover onto the LCD display meter body.
Table 1. LCD Display Mode Options
Options Relationship between input signal and digital display
L in Linear
LinF Linear with five-second filter
Srt Square root
SrtF Square root with five-second filter
Square root function only relates to the digital display. The bar graph output remains
linear with the current signal.
Square root response
The digital display will be proportional to the square root of the input current where 4 mA = 0 and 20 mA =
1.0, scaled per the calibration procedure. The transition point from linear to square root is at 25 percent of
full scale flow.
Filter response operates upon “present input” and “input received in the previous five
second interval” in the following manner:
Display = (0.75 previous input) + (0.25 present input)
This relationship is maintained provided that the previous reading minus the present
reading is less than 25 percent of full scale.
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