Emerson Rosemount 848T User manual

Quick Start Guide
00825-0100-4697, Rev WB
December 2021
Rosemount™ 848T FOUNDATION™ Fieldbus
High Density Temperature Transmitter

Contents
Introduction.................................................................................................................................3
Mount the transmitter..................................................................................................................7
Wire and apply power................................................................................................................ 15
Verify the tag............................................................................................................................. 22
Verify the transmitter configuration...........................................................................................23
Product certifications................................................................................................................. 24
Declaration of conformity.......................................................................................................... 36
China RoHS................................................................................................................................ 38
Quick Start Guide December 2021
2 Rosemount 848T

1 Introduction
The Rosemount 848T is optimized for process temperature measurement
because it can simultaneously measure eight separate and independent
temperature points with one transmitter. You can connect multiple
temperature sensor types to each transmitter. In addition, the Rosemount
848T can accept 4-20 mA inputs. The enhanced measurement capability of
the Rosemount 848T allows it to communicate these variables to any
FOUNDATION™ Fieldbus host or configuration tool.
1.1 About this guide
This guide provides basic guidelines for the Rosemount 848T Temperature
Transmitter. It does not provide instructions for detailed configuration,
diagnostics, maintenance, service, troubleshooting. Refer to the Rosemount
848T Reference Manual for more instruction. The manual and this guide are
also available electronically on Emerson.com/Rosemount.
1.2 Hazard messages
This document uses the following criteria for hazard messages based on
ANSI standards Z535.6-2011 (R2017).
DANGER
Serious injury or death will occur if a hazardous situation is not avoided.
WARNING
Serious injury or death could occur if a hazardous situation is not avoided.
CAUTION
Minor or moderate injury will or could occur if a hazardous situation is not
avoided.
NOTICE
Data loss, property damage, hardware damage, or software damage can
occur if a situation is not avoided. There is no credible risk of physical injury.
December 2021 Quick Start Guide
Quick Start Guide 3

Physical access
NOTICE
Unauthorized personnel can potentially cause significant damage and/or
misconfiguration of end users' equipment. Protect against all intentional or
unintentional unauthorized use.
Physical security is an important part of any security program and
fundamental to protecting your system. Restrict physical access to protect
users' assets. This is true for all systems used within the facility.
1.3 Safety messages
Read this manual before working with the product. For personal and system
safety, and for optimum product performance, ensure you thoroughly
understand the contents before installing, using, or maintaining this
product.
WARNING
Explosions could result in death or serious injury.
Installation of this transmitter in an explosive environment must be in
accordance with the appropriate local, national, and international standards,
codes, and practices. Review the approvals section of this manual for any
restrictions associated with a safe installation.
Before connecting a Field Communicator in an explosive atmosphere, make
sure the instruments in the loop are installed in accordance with intrinsically
safe or non-incendive field wiring practices.
WARNING
Failure to follow these installation guidelines could result in death or
serious injury.
Ensure the transmitter is installed by qualified personnel and in accordance
with applicable code of practice.
WARNING
Process leaks could result in death or serious injury.
Do not remove the thermowell while in operation.
Install and tighten thermowells and sensors before applying pressure.
Quick Start Guide December 2021
4 Rosemount 848T

WARNING
Electrical shock could cause death or serious injury.
If the sensor is installed in a high-voltage environment and a fault or
installation error occurs, high voltage may be present on transmitter leads
and terminals.
Use extreme caution when making contact with the leads and terminals.
CAUTION
This device complies with Part 15 of the FCC Rules. Operation is subject to
the following conditions:
•This device may not cause harmful interference.
•This device must accept any interference received, including
interference that may cause undesired operation.
•This device must be installed to ensure a minimum antenna separation
distance of 7.9 in. (20 cm) from all persons.
NOTICE
Battery hazards remain when cells are discharged.
The power module may be replaced in a hazardous area. The power module
has surface resistivity greater than one gigaohm and must be properly
installed in the wireless device enclosure. Care must be taken during
transportation to and from the point of installation to prevent electrostatic
charge build-up.
Shipping considerations for wireless products.
•The unit was shipped to you without the power module installed.
Remove the power module prior to any re-shipping.
•Each power module contains two “C” size primary lithium batteries.
Primary lithium batteries are regulated in transportation by the U. S.
Department of Transportation, and are also covered by IATA
(International Air Transport Association), ICAO (International Civil
Aviation Organization), and ARD (European Ground Transportation of
Dangerous Goods). It is the responsibility of the shipper to ensure
compliance with these or any other local requirements. Consult current
regulations and requirements before shipping.
December 2021 Quick Start Guide
Quick Start Guide 5

1.4 Product recycling/disposal
Recycling of equipment and packaging should be taken into consideration
and disposed of in accordance with local and national legislation/
regulations.
Quick Start Guide December 2021
6 Rosemount 848T

2 Mount the transmitter
2.1 Mount to a DIN rail without an enclosure
To mount the transmitter to a DIN rail without an enclosure, follow these
steps:
Procedure
1. Pull up the DIN rail mounting clip located on the top back side of the
transmitter.
2. Hinge the DIN rail into the slots on the bottom of the transmitter.
3. Tilt the transmitter and place onto the DIN rail. Release the mounting
clip. The transmitter should be securely fastened to the DIN rail.
Figure 2-1: Mount the transmitter to a DIN rail
A. Rosemount 848T without installed enclosure
B. DIN rail mounting clip
C. DIN rail
2.2 Mount to a panel from an aluminum junction box
Prerequisites
Use four 1/4-20 x 1.25-in. screws.
Procedure
Mount the transmitter to a panel from inside the junction box using one of
the following dimension drawings.
December 2021 Quick Start Guide
Quick Start Guide 7

Figure 2-2: Aluminum junction box with cable glands (option code JA4)
10.21
[259]
A
1.70
[43]
B
6.70
[170]
CD
3.67
[93]
E
.80
[20]
2.30
[58]
2.27
[58]
1.33
[34]
1.88
[48]
3.98
[101]
8.42
[214] 6.00
[152]
A. Nameplate
B. Removable wiring connector
C. Security switch
D. Simulation switch
E. External ground screw (optional)
Dimensions are in inches (millimeters).
Quick Start Guide December 2021
8 Rosemount 848T

Figure 2-3: Aluminum junction box with plugged holes (option code
JA5)
A
10.21
[259]
1.70
[43]
B
6.70
[170] CD
.80
[20]
2.30
[58]
3.21
[81]
1.33
[34]
1.88
[48]
3.97
[101]
E
7.14
[181]
6.00
[152]
A. Nameplate
B. Removable wiring connection
C. Security switch
D. Simulation switch
E. External ground screw (optional)
Dimensions are in inches (millimeters).
2.3 Mount to a panel from a stainless steel junction box
Prerequisites
Use two 1/4-20 x 1/2-in. screws.
Procedure
Mount the transmitter to a panel from inside the junction box using one of
the following dimension drawings.
December 2021 Quick Start Guide
Quick Start Guide 9

Figure 2-4: Stainless steel junction box with cable glands (option code
JS2)
9.91 (231)
7.7 (196)
C
1.8 (46)
1.1 (28) 1.73 (44)
2.4 (62)
1.2 (30) 1.8 (47)
4.0 (102)
9.14 (232.2)
7.72 (196)
6.61 (168)
A B
D E
A. Top view
B. 3-D view
C. Ground screw
D. Front view
E. Side view
Dimensions are in inches (millimeters).
Quick Start Guide December 2021
10 Rosemount 848T

Figure 2-5: Stainless steel junction box with a conduit entry (option
code JS3)
9.1 (231)
7.7 (196)
C
A
4.0 (102)
B
1.4 (35)
1.1 (27) 2.8 (70)
4.0 (102)
1.8 (4.7)
2.4 (62)
1.6 (42)
F
D1.2 (30) E
A. Top view
B. 3-D view
C. Ground screw
D. Front view
E. Side view
F. Five plugged 0.86 in (21.8 mm) diameter holes suitable for installing ½-
in. NPT fittings
Dimensions are in inches (millimeters).
2.4 Mount to a 2 in (51 mm) pipe stand
Procedure
Use the optional mounting bracket (option code B6) to mount the
transmitter to a 2 in (51 mm) pipe stand when using a junction box.
December 2021 Quick Start Guide
Quick Start Guide 11

Figure 2-6: Mount an aluminum junction box
․
‥
A B
5.08
[129]
7.55
[193]
A. Front view
B. Side view
Dimensions are in inches (millimeters)
Quick Start Guide December 2021
12 Rosemount 848T

Figure 2-7: Mount a stainless steel junction box
4.7 (119)
7.5 (190)
C
A B
A. Front view
B. Side view
C. Fully assembled
Dimensions are in inches (millimeters)
December 2021 Quick Start Guide
Quick Start Guide 13

Figure 2-8: Mount aluminum on a vertical pipe
Figure 2-9: Mount stainless steel on vertical pipe
Quick Start Guide December 2021
14 Rosemount 848T

3 Wire and apply power
3.1 Using cable glands
Procedure
1. Remove the junction box cover by unscrewing the cover screws.
2. Run the sensor and power/signal wires through the appropriate cable
glands (see Figure 3-1).
3. Install the sensor wires into the correct screw terminals (follow the
label on the electronics module).
4. Install the power/signal wires onto the correct screw terminals.
Power is polarity insensitive, allowing the user to connect positive (+)
or negative (–) to either fieldbus wiring terminal labeled “Bus”.
5. Replace the enclosure cover and securely tighten all cover screws.
December 2021 Quick Start Guide
Quick Start Guide 15

Figure 3-1: Installing the transmitter with cable glands
%+,-.&'()*$
A. Enclosure cover screws (2)
B. Cable glands (9)
C. Sensor 1
D. Sensor 3
E. Sensor 5
F. Sensor 7
G. Power/signal
H. Sensor 2
I. Sensor 4
J. Sensor 6
K. Sensor 8
Quick Start Guide December 2021
16 Rosemount 848T

3.2 Sensor wiring and power supply
•Compatible with eight independently configurable channels including
combinations of 2- and 3-wire RTDs, thermocouples, mV, ohm, and mA
sensors.
•All sensor and power terminals are rated to 42.4 Vdc.
•FOUNDATION Fieldbus network powered with a terminal voltage of 9.0–
32.0 Vdc and 22 mA maximum current draw.
•For best network performance twisted, shielded pair cabling should be
used. Proper gage wire should be selected to maintain the 9.0 Vdc
minimum.
Figure 3-2: Sensor Wiring Diagrams
1 1 1 12 2 2 23 3 3 3
2-wire RTD and
Ohms
3-wire RTD and
Ohms(1)
Thermocouples/
Ohms and
millivolts
2-Wire RTD with
compensation
loop(2)
(1) Emerson provides 4-wire sensors for all single-element RTDs. Use these RTDs in
3-wire configurations by clipping the fourth lead or leaving it disconnected and
insulated with electrical tape.
(2) The transmitter must be configured for a 3-wire RTD in order to recognize an
RTD with a compensation loop.
The wiring of 3-wire RTDs for this unit is different than some earlier
Rosemount 848T models. Pay careful attention to the wiring diagram on the
label, especially if this unit is replacing an older unit.
December 2021 Quick Start Guide
Quick Start Guide 17

3.3 Wiring analog inputs
Figure 3-3: Rosemount 848T Analog Input Wiring Diagram
A
C
B
A. Analog input connectors
B. Analog transmitters
C. Power supply
3.4 Typical configuration for FOUNDATION Fieldbus networking
Note
Each segment in a FOUNDATION Fieldbus trunk must be terminated at both
ends.
Quick Start Guide December 2021
18 Rosemount 848T

%$&))*+'(
A. Integrated power conditioner and filter
B. 6234 ft. (1900 m) max (depending upon cable characteristics)
C. Terminators (trunk)
D. Power supply
E. FOUNDATION Fieldbus host or configuration tool
F. Spurs
G. Signal wiring
H. Devices 1-16 (intrinsically safe installations may allow fewer devices per
I.S. barrier)
3.4.1 Ground the transmitter
Proper ground is crucial to reliable temperature readings.
3.4.2 Ungrounded thermocouple, mV, and RTD/Ohm inputs
Option 1
Procedure
1. Connect FOUNDATION Fieldbus signal wiring shield to the sensor wiring
shield(s).
2. Ensure the shields are tied together and electrically isolated from the
transmitter enclosure.
3. Only ground the shield at the power supply end.
4. Ensure that the sensor shield(s) is electrically isolated from the
surrounding grounded fixtures.
December 2021 Quick Start Guide
Quick Start Guide 19

A
BC
D
A. Sensor wires
B. Rosemount 848T
C. Power supply
D. Shield ground point
Option 2
Procedure
1. Connect sensor wiring shield(s) to the transmitter enclosure (only if
the enclosure is grounded).
2. Ensure the sensor shield(s) is electrically isolated from surrounding
fixtures that may be grounded.
3. Ground FOUNDATION Fieldbus signal wiring shield at the power supply
end.
A
BC
D
A. Sensor wires
B. Rosemount™ 848T
C. Power supply
D. Shield ground point
3.4.3 Grounded thermocouple inputs
Procedure
1. Ground sensor wiring shield(s) at the sensor.
2. Ensure the sensor wiring and FOUNDATION Fieldbus signal wiring
shields are electrically isolated from the transmitter enclosure.
3. Do not connect the FOUNDATION Fieldbus signal wiring shield to the
sensor wiring shield(s).
Quick Start Guide December 2021
20 Rosemount 848T