Emerson Rosemount 644, Reference Manual

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51
Reference Manual
00809-0200-4728, Rev RA
Section 3: Hardware installation
April 2015
Hardware Installation
Head mount transmitter with threaded sensor installation
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. Seal the nipple and
adapter threads with silicone tape.
3. Screw the sensor into the thermowell. Install drain seals if required for severe
environments or to satisfy code requirements.
4. Verify the transmitter failure mode switch is in the desired position.
5. To verify the correct installation of Integral Transient Protection (option code T1) on the
Rosemount 644 device, confirm the following steps have been completed:
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.
Note
The transient protector requires the use of an enclosure of at least 3.5 in (89 mm) in diameter.
6. Pull the sensor wiring leads through the universal head and transmitter. Mount the
transmitter in the universal head by threading the transmitter mounting screws into
the universal head mounting holes.
7. Seal adapter threads with thread sealant.
8. Pull the field wiring leads through the conduit into the universal head. Wire the sensor
and power leads to the transmitter (see
“Wiring and powering the transmitter” on
page 58 ). Avoid contact with other terminals.
9. Install and tighten the universal head cover. Enclosure covers must be fully engaged to
meet explosion-proof requirements.
A. 644 Transmitter
B. Universal junction box
C. Threaded style sensor D. Extension
E. Threaded thermowell
A
B
C
D
E