Instruction Manual

Instruction Manual
D102803X012
249W Sensor
December 2012
16
against the gasket. With a thumb on the upper portion of the positioning plate and a screwdriver in the slots as
shown in figure 13, rotate the plate and press the lug on the plate into the hole in the torque tube arm (this will
preload the torque tube).
8. Install the retaining flange and secure it with four nuts (key 18), being sure to tighten all nuts evenly.
9. Install the torque tube arm on the wafer body and secure it with the proper bolting (keys 19 and 20).
10. Install the sensor and controller/transmitter. Calibrate the controller/transmitter following the procedures given in
the controller/transmitter instruction manual.
Changing the Mounting from Left‐Hand to Right‐Hand or Vice Versa.
Looseness of the driver bearing (key 7), wear on its knife‐edged surface, or a bent, worn, or corroded displacer
rod/driver assembly (key 5) may impair performance. Be especially sure to check the ball on the displacer rod.
CAUTION
Support the sensor assembly to avoid damage to the displacer, displacer stem, displacer rod assembly, and associated
parts.
1. After following the proper procedure to remove the sensor and the displacer from the process vessel or displacer
cage, move the sensor assembly to a suitable maintenance area.
2. Remove the controller/transmitter and displacer (key 4). Then, remove the hex nuts (key 20) that hold the torque
tube arm (key 2) to the wafer body (key 1). Separate the torque tube arm from the wafer body.
3. Follow the proper procedure to remove the torque tube assembly (key 3).
4. Remove the driver bearing bolts (key 8), displacer rod/driver assembly (key 5), and driver bearing (key 7).
Note
Be sure to install the driver bearing so its knife edge is pointing up when the torque tube arm is mounted in the desired orientation.
Since changing the mounting position of the torque tube arm by 180_ will change controller or transmitter action from direct to
reverse or vice versa, controller/transmitter action must be reversed from what it was before the mounting method was changed.
5. Install the driver bearing (key 7), displacer rod/driver assembly (key 5), and bearing bolts (key 8) into the torque
tube arm (key 2). Install a new arm gasket (key 12). Install the torque tube arm on the wafer body and secure it with
the proper bolting (keys 19 and 20).
6. Install the sensor and controller/transmitter. Calibrate the controller/transmitter following the procedures given in
the controller/transmitter instruction manual.
Simulation of Process Conditions for Calibration of Fisher Level
Controllers and Transmitters
Contact your Emerson Process Management sales office for information on obtaining the Supplement to 249 Sensor
Instruction Manuals: Simulation of Process Conditions for Calibration of Fisher Level Controllers and Transmitter
(D103066X012).