Emerson Rosemount 644h, Reference Manual

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Reference Manual
00809-0100-4728, Rev HA
December 2002
2-5
Models 644H and 644R
Typical North American
Installation
Head Mount Transmitter with Threaded Sensor
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.
5. 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.
6. Mount the transmitter-sensor assembly into the thermowell. Seal
adapter threads with silicone tape.
7. Install conduit for field wiring to the conduit entry of the universal
head. Seal conduit threads with silicone tape.
8. 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.
9. Install and tighten the universal head cover. Enclosure covers must
be fully engaged to meet explosion-proof requirements.
A = Threaded Thermowell D = Universal Head
B = Threaded Style Sensor E = Conduit Entry
C = Standard Extension
A
B
C
D
E