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2502 Series Controllers
Instruction Manual
Form 1446
November 2006
20
3. Remove any insulating tape from the joint
between the controller case and the torque tube
arm. Remove the four cap screws (key 39, figure 12)
that hold the controller or heat insulator to the torque
tube arm. Pull the case straight out from the torque
tube arm, easing it over the shaft coupling (key 36,
figure 12) if one is installed.
4. If the controller has a heat insulator, remove the
button head cap screws (key 40). Remove four
washers (key 53) and the insulator assembly
(key 35).
Changing Mounting Method
WARNING
To avoid personal injury from contact
with the process liquid, lower the
vessel level below the torque-tube arm
before proceeding. For closed vessels,
release any pressure that may be
above the liquid. Also, be careful to
avoid overloading a thin-wall torque
tube and/or oversized displacer.
Refer to figure 14 for key number locations.
1. Remove the controller as described previously.
2. A controller is attached to the sensor in one or
the other of the mounting positions shown in
figure 4. Right hand mount is with the case to the
right of the displacer when looking at the front of the
case. Left hand mount is with the case to the left of
the displacer. For a 249 Series sensor, remove the
torque tube arm from the sensor or vessel and
reinstall the torque tube arm in the opposite position
according to the appropriate instruction manual.
3. Check the desired control action to determine if it
is also necessary to reverse the controller action.
The nozzle block and bellows tubing should be
arranged in the proper position as shown in
figure 13.
4. Remove the RAISE LEVEL dial, turn it over, and
install it in the desired position. The arrow on it under
the word FLOAT should point toward the displacer.
On a controller with indicator assembly, remove two
screws (key 41, figure 14), turn the front plate
(key 54, figure 14) to the side that will have the float
arrow pointing toward the displacer, and secure the
plate with the screws.
5. Install the controller according to the next section.
20A7423-C/DOC
Figure 12. Heat Insulator Shown Installed on 249 Series
Installing Controller on Sensor
Note
If the installation is in a location that is
not readily accessible and shop
calibration is required, remove the
torque tube arm from the cage or
vessel before mating the controller to
the sensor. Install the controller on the
torque tube arm in the shop; then
calibrate and return the controller and
torque tube arm assembly to the
installation.
Perform step 1 only if adding a heat insulator to
a unit that does not have one. Key numbers in
this step are shown in figure 12, unless
otherwise indicated.
1. To install the heat insulator, secure the shaft
extension (key 37) to the torque tube assembly
rotary shaft with the shaft coupling (key 36). Tighten
both set screws (key 38), with the coupling centered