Sensor Connections - Emerson Rosemount 644 FOUNDATION Reference Manual

Installation
September 2018
Figure 3-6. Connecting a F
Integrated power conditioner
filter, first terminator,
3.5.1

Sensor connections

The Rosemount 644 is compatible with a number of RTD and thermocouple sensor types.
shows the correct input connections to the sensor terminals on the transmitter. To ensure a proper
sensor connection, anchor the sensor lead wires into the appropriate compression terminals and tighten
the screws.
Figure 3-7. Sensor Wiring Diagrams
Rosemount 644 sensor connections diagram
1 2 3 4
2-wire
RTD and
1. Emerson
leads disconnected and insulated with electrical tape.
Thermocouple or millivolt inputs
The thermocouple can be connected directly to the transmitter. Use appropriate thermocouple
extension wire if mounting the transmitter remotely from the sensor. Make millivolt inputs connections
with copper wire. Use shielding for long runs of wire.
36
OUNDATION
and filter
Power
supply
(The power supply,
and configuration
configuration
tool are typically
located in the control
room.)
1 2 3 4
1 2 3 4
4-wire RTD
(1)
3-wire RTD
and
and
™
provides 4-wire sensors for all single element RTDs. Use these RTDs in 3-wire configurations by leaving the unneeded
Fieldbus Host System to a Transmitter Loop
6234 ft. (1900 m) max
(depending upon cable characteristics)
Terminators
(Trunk)
F
OUNDATION
Fieldbus
tool
(1)
1 2 3 4
T/C
and mV
00809-0400-4728, Rev CA
Power/
Devices 1 signal wiring
through 16
Reference Manual
Figure 3-7
Installation