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NEW TRANSMITTER
NEW TRANSMITTER
Transmitter Design
Sensor Wiring Diagrams
Special Mounting
Considerations
HART Communicator
(Model 644H only)
To guarantee proper transmitter functionality and communication, your Model
275 HART Communicator should contain device revision Dev v5 DD v2 or
higher. To check software device revision,
1. Turn on the communicator.
2. Select 1 Off-line, 1 New Configuration, Rosemount, 644 Temp
If you do not have this device revision, contact your local Rosemount
representative for information on receiving an upgrade.
Models 644H and 244EH Models 644R and 244ER
Captive Mounting Screws and Springs
Meter Connector
(Model 644H only)
Hole in Middle
of Transmitter
644, 244-1360A02B
Models 644 and 244E
* Rosemount Inc. provides 4-wire sensors for all single element RTDs. You can use these RTDs in
3-wire configurations by leaving the unneeded leads disconnected and insulated with
electrical tape.
** The transmitters must be configured for a 3-wire RTD in order to recognize an RTD with a
compensation loop.
1234
234
12 34 12
3
4
1234
2-wire
RTD
and ⍀
3-wire
RTD
and ⍀
4-wire
RTD
and ⍀
T/C and
mV
1
***
RTD with
Comp.
Loop
644-0000B01C
UsewithanExistingDINPlateStyleSensor
1. Secure the bottom of the mounting screw sleeve
with pliers. Remove the mounting screws and
springs.
2. Once the springs are removed, use the new
transmitter mounting screws to assembly
the transmitter to the DIN plate and connection
head. (Optional snap rings (part number
00644-4432-0001) are available to ease installation
to the existing DIN plate style sensor.)
UsewithanExistingThreadedSensorConnectionHead
To mount the new Models 644H or 244EH to the existing
threaded sensor connection head (former option code L1),
order the models 644H and 244EH retrofit kit (part number
00644-5321-0010). The fit includes a new mounting
bracket and all associated hardware necessary to facilitate
the installation of the Models 644H and 244EH into the
existing head.
Mounting
Springs
and
Screws
Mounting
Screw
Sleeves
SENSORS-0000A02B
Model 644H or
Model 244EH
Existing
Threaded Sensor
Connection Head
Kit includes
replacement bracket
and screw
644-644-5321A01A,