Quick Start Guide
00825-0200-4728, Rev LB
May 2022
Rosemount™ 644 Temperature
Transmitter
with 4–20 mA HART® Protocol (Revision 5
and 7)
Quick Start Guide May 2022
Contents
About this guide...........................................................................................................................3
System readiness......................................................................................................................... 5
Transmitter installation................................................................................................................ 6
Safety instrumented systems..................................................................................................... 24
Product certifications................................................................................................................. 25
Declaration of Conformity..........................................................................................................43
China RoHS................................................................................................................................ 47
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May 2022 Quick Start Guide
1 About this guide
This guide provides basic guidelines for installing the Rosemount 644
Temperature Transmitter. It does not provide instructions for detailed
configuration, diagnostics, maintenance, service, troubleshooting, or
installation. Refer to the Rosemount 644 Reference Manual for more
instruction. The manual and this guide are also available electronically on
Emerson.com/Rosemount.
Safety messages
WARNING
The products described in this document are NOT designed for nuclearqualified applications.
Using non-nuclear qualified products in applications that require nuclearqualified hardware or products may cause inaccurate readings.
For information on Rosemount nuclear-qualified products, contact your
local Emerson Sales Representative.
Follow instructions
Failure to follow these installation guidelines could result in death or serious
injury.
Ensure only qualified personnel perform the installation.
Physical access
Unauthorized personnel may potentially cause significant damage to and/or
misconfiguration of end users’ equipment. This could be intentional or
unintentional and needs to be protected against.
Physical security is an important part of any security program and
fundamental to protecting your system. Restrict physical access by
unauthorized personnel to protect end users’ assets. This is true for all
systems used within the facility.
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WARNING
Explosions
Explosions could result in death or serious injury.
Installation of the transmitters in a hazardous environment must be in
accordance with the appropriate local, national, and international
standards, codes, and practices. Please review the Product Certifications
section for any restrictions associated with a safe installation.
Do not remove the connection head cover in explosive atmospheres
when the circuit is live.
Before connecting a handheld communicator in an explosive
atmosphere, ensure the instruments are installed in accordance with
intrinsically safe or non-incendive field wiring practices.Verify the
operating atmosphere of the transmitter is consistent with the
appropriate hazardous locations certifications.
All connection head covers must be fully engaged to meet explosionproof requirements.
Process leaks
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.
Electrical shock
Electrical shock could cause death or serious injury.
Avoid contact with the leads and terminals. High voltage that may be
present on leads can cause electrical shock.
CAUTION
Conduit/cable entries
Unless otherwise marked, the conduit/cable entries in the housing
enclosure use a ½–14 NPT form. Only use plugs, adapters, glands, or
conduit with a compatible thread form when closing these entries.
Entries marked "M20" are M20 x 1.5 thread form.
When installing in a hazardous location, use only appropriately listed or
Ex certified plugs, glands, or adapters in cable/conduit entries.
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May 2022 Quick Start Guide
2 System readiness
2.1 Confirm HART® revision capability
If using HART-based control or asset management systems, confirm the
HART capability of those systems prior to transmitter installation. Not all
systems are capable of communicating with HART Revision 7 Protocol. You
can configure the transmitter for either HART Revision 5 or 7.
2.2 Confirm correct device driver
Procedure
1. Verify the latest Device Driver files are loaded on your systems to
ensure proper communications.
2. Download the latest Device Driver at Emerson.com/Device-Install-
Kits/Device-Install-Kit-Search
Table 2-1 provides the information necessary to ensure the correct
Device Driver files and documentation are being used.
Table 2-1: Device Revisions and Files
Software
date
June 2012 1.1.1 3 5 8 00809-010
NAMUR
Software
revision
®
HART
Software
revision
HART
Universal
(1)
revision
7 9
Device
revision
(2)
Manual
Document
Number
0-4728
Changes to
Software
(3)
See
for
list of
changes.
(3)
(1) NAMUR software revision is located on the hardware tag of the device. HART software
revision can be read using a HART communication tool.
(2) Device Driver file names use Device and DD Revision (e.g. 10_01. HART Protocol) is designed
to enable legacy device driver revisions to continue to communicate with new HART devices.
To access new functionality, download the new Device Driver. Emerson recommends
downloading new Device Driver files to ensure full functionality.
(3) HART Revision 5 and 7 Selectable, Dual Sensor support, Safety Certified, Advanced
Diagnostics (if ordered), Enhanced Accuracy and Stability (if ordered).
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Quick Start Guide May 2022
3 Transmitter installation
3.1 Mount the transmitter
Mount the transmitter at a high point in the conduit run to prevent moisture
from draining into the transmitter housing.
3.1.1 Head mount transmitter with DIN plate style sensor installation
WARNING
Enclosure
Enclosure covers must be fully engaged to meet explosion-proof
requirements.
Procedure
1. Attach the thermowell to the pipe or process container wall.
2. Install and tighten the thermowell before applying process pressure.
3. Verify the transmitter failure mode switch position.
4. Assemble the transmitter to the sensor. Push the transmitter
mounting screws through the sensor mounting plate.
5. Wire the sensor to the transmitter.
6. Insert the transmitter-sensor assembly into the connection head.
a) Thread the transmitter mounting screw into the connection
head mounting holes.
b) Assemble the extension to the connection head.
c) Insert the assembly into the thermowell.
7. If using a cable gland, properly attach the cable gland to a housing
conduit entry.
8. Insert the shielded cable leads into the connection head through the
cable entry.
9. Connect the shielded power cable leads to the transmitter power
terminals.
Avoid contact with sensor leads and sensor connections.
10. Connect and tighten the cable gland.
11. Install and tighten the connection head cover.
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May 2022 Quick Start Guide
A. Connection head cover
B. Connection head
C. Thermowell
D. Transmitter mounting screws
E. Integral mount sensor with flying leads
F. Extension
3.1.2 Head mount transmitter with threaded sensor installation (two or three conduit entries)
WARNING
Enclosure
Enclosure covers must be fully engaged to meet explosion-proof
requirements.
Procedure
1. Attach the thermowell to the pipe or process container wall.
2. Install and tighten thermowells before applying process pressure.
3. Attach necessary extension nipples and adapters to the thermowell.
4. Seal the nipple and adapter threads with silicone tape.
5. Screw the sensor into the thermowell. Install drain seals if required
for severe environments or to satisfy code requirements.
6. Verify the transmitter failure mode switch is in the desired position.
7. Verify the correct installation of Integral Transient Protection (option
code T1).
a) Ensure the transient protector unit is firmly connected to the
transmitter puck assembly.
b) Ensure the transient protector power leads are adequately
secured under the transmitter power terminal screws.
c) Verify the transient protector’s ground wire is secured to the
internal ground screw found within the universal head.
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Quick Start Guide May 2022
Note
The transient protector requires the use of an enclosure of at least
3.5-in. (89 mm) in diameter.
8. Pull the sensor wiring leads through the universal head and
transmitter center hole.
9. Mount the transmitter in the universal head by threading the
transmitter mounting screws into the universal head mounting
holes.
10. Mount the transmitter-sensor assembly into the thermowell, or
remote mount if desired.
11. Seal adapter threads with silicone tape.
12. Pull the field wiring leads through the conduit into the universal
head. Attach the sensor and power leads to the transmitter.
Avoid contact with other terminals.
13. Install and tighten the universal head cover.
A. Threaded thermowell
B. Threaded style sensor
C. Universal head (transmitter inside)
D. Standard extension
E. Conduit entry
3.1.3 Field mount transmitter with threaded sensor installation
WARNING
Enclosure
Enclosure covers must be fully engaged to meet explosion-proof
requirements.
Procedure
1. Attach the thermowell to the pipe or process container wall. Install
and tighten thermowells before applying process pressure.
2. Attach necessary extension nipples and adapters to the thermowell.
8 Rosemount 644
A
C
B
D
E
May 2022 Quick Start Guide
3. Seal the nipple and adapter threads with silicone tape.
4. Screw the sensor into the thermowell. Install drain seals if required
for severe environments or to satisfy code requirements.
5. Verify the transmitter failure mode switch is in the desired position.
6. Mount the transmitter-sensor assembly into the thermowell or
remote mount if desired.
7. Seal adapter threads with silicone tape.
8. Pull the field wiring leads through the conduit into the field mount
housing. Wire the sensor and power leads to the transmitter.
Avoid contact with other terminals.
9. Install and tighten the covers of two compartments.
A. Threaded thermowell
B. Threaded style sensor
C. Standard extension
D. Field mount housing (transmitter inside)
E. Conduit entry
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3.2 Wire and apply power
3.2.1 Wire the sensor to the transmitter
Figure 3-1: Rosemount 644 Head Mount - Single and Dual Input Wiring
Diagrams
• The transmitter must be configured for at least a three-wire RTD in order
to recognize an RTD with a compensation loop.
• Emerson provides a four-wire sensors for all single element RTDs. Use
these RTDs in three-wire configurations by leaving the unneeded leads
disconnected and insulated with electrical tape.
Figure 3-2: Rosemount 644 Field Mount — Single and Dual Input Wiring
Diagrams
3.2.2 Power the transmitter
An external power supply is required to operate the transmitter.
Procedure
1. Remove the housing cover (if applicable).
2. Connect the positive power lead to the “+” terminal. Connect the
negative power lead to the “–” terminal.
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May 2022 Quick Start Guide
If a transient protector is being used, the power leads will now be
connected to the top of the transient protector unit. See the
transient label for indication of “+” and “–“ terminal connections.
3. Tighten the terminal screws. When tightening the sensor and power
wires, the max torque is 6 in-lb (0.7 N-m).
4. Reattach and tighten the cover (if applicable).
WARNING
Enclosue
Enclosure covers must be fully engaged to meet explosion-proof
requirements.
5. Apply power (12–42 Vdc).
3.2.3 Load limitation
The power required across the transmitter power terminals is 12 to 42.4
Vdc; the power terminals are rated to 42.4 Vdc. To prevent damaging the
transmitter, do not allow terminal voltage to drop below 12.0 Vdc when
changing the configuration parameters.
3.2.4 Ground the transmitter
To ensure proper grounding, it is important the instrument cable shield be:
• Trimmed close and insulated from touching the transmitter housing
• Connected to the next shield if cable is routed through a junction box
• Connected to a good earth ground at the power supply end
Note
Shielded twisted pair cable should be used for best results. Use 24 AWG or
larger wire and do not exceed 5,000 ft. (1500 m).
Ungrounded thermocouple, mV, and RTD/Ohm inputs
Each process installation has different requirements for grounding. Use the
grounding options recommended by the facility for the specific sensor type,
or begin with grounding option 1 (the most common).
Quick Start Guide 11
A
B
C
DCS
D
Quick Start Guide May 2022
Ground the transmitter: option 1
Procedure
1. Connect sensor wiring shield to the transmitter housing.
2. Ensure the sensor shield is electrically isolated from surrounding
fixtures that may be grounded.
3. Ground signal wiring shield at the power supply end.
A. Sensor wires
B. Transmitter
C. Shield ground point
D. 4-20 mA loop
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A
B
C
D
DCS
May 2022 Quick Start Guide
Ground the transmitter: option 2
Procedure
1. Connect signal wiring shield to the sensor wiring shield.
2. Ensure the two shields are tied together and electrically isolated from
the transmitter housing.
3. Ground shield at the power supply end only.
4. Ensure the sensor shield is electrically isolated from the surrounding
grounded fixtures.
A. Sensor wires
B. Transmitter
C. Shield ground point
D. 4-20 mA loop
Note
Connect shields together, electrically isolated from the transmitter.
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DCS
A
B
C
D
Quick Start Guide May 2022
Ground the transmitter: option 3
Procedure
1. Ground sensor wiring shield at the sensor if possible.
2. Ensure the sensor wiring and signal wiring shields are electrically
isolated from the transmitter housing.
3. Do not connect the signal wiring shield to the sensor wiring shield.
4. Ground the signal wiring shield at the power supply end.
A. Sensor wires
B. Transmitter
C. Shield ground point
D. 4-20 mA loop
14 Rosemount 644
DCS
A
B
C
D
May 2022 Quick Start Guide
Grounded thermocouple inputs
Ground the transmitter: option 4
Procedure
1. Ground sensor wiring shield at the sensor.
2. Ensure the sensor wiring and signal wiring shields are electrically
isolated from the transmitter housing.
3. Do not connect the signal wiring shield to the sensor wiring shield.
4. Ground signal wiring shield at the power supply end.
A. Sensor wires
B. Transmitter
C. Shield ground point
D. 4–20 mA loop
3.3
Set the alarm switch
Set the alarm switch before putting the device into operation.
Procedure
1. Set the loop to manual (if applicable) and disconnect the power.
2. Remove the LCD display by detaching from the transmitter (if
applicable).
3. Set the switch to the desired position.
H indicates High; L indicates Low.
4. Reattach the LCD display to the transmitter (if applicable).
5. Reattach the housing cover. Ensure covers must be fully engaged to
meet explosion-proof requirements.
6. Apply power and set the loop to automatic control (if applicable).
Quick Start Guide 15
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