Changing Mounting Methods - Fisher 2500 Series Instruction Manual

2. Loosen the top hex clamp nut (key 40, figure 19)
and remove the flapper base (key 30, figure 19) from
the torque tube rotary shaft.
CAUTION
If the hex clamp nut has not been loos-
ened or the pointer removed according
to step 2, attempting to remove the con-
troller/transmitter from the sensor may
bend the flapper or rotary shaft. Be care-
ful that the back of the controller/trans-
mitter case or the heat insulator does
not drop down and bend the rotary shaft
or shaft extension.
3. Remove any insulating tape from the joint between
the controller/transmitter case and the torque tube
arm. Remove the four cap screws (key 39, figure 16)
that hold the controller/transmitter 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 16) if one is installed.
4. If the controller/transmitter has a heat insulator,
remove the four button head cap screws and washers
(keys 40 and 53, figure 16) and remove the insulator
assembly.

Changing Mounting Methods

WARNING
To avoid personal injury from contact
with the process fluid, lower the vessel
fluid level below the torque-tube arm be-
fore proceeding. For closed vessels, re-
lease any pressure that may be above
the fluid. Also, be careful to avoid over-
loading a thin-wall torque tube with an
overweight displacer.
Refer to figure 19 for key number locations.
1. Remove the controller/transmitter as described pre-
viously.
2. A controller/transmitter is attached to the sensor in
one of the mounting positions shown in figure 4. Right-
hand mounting is with the controller/transmitter case
(key 1) to the right of the displacer (FLOAT), as you
look at the front of the case, left-hand mounting is with
with the case to the left of the displacer. For a 249 Se-
ries sensor, remove the torque tube arm from the sen-
sor or vessel and reinstall the torque tube arm in the
20A7423–C/DOC
Figure 16. Heat Insulator for 249 Series Sensor
opposite position according to the appropriate instruc-
tion manual. Note that the term FLOAT is marked on
the RAISE LEVEL dial and the indicator plate, if one is
used.
3. Check the desired control action. If the control ac-
tion is not correct, refer to the changing action proce-
dures to change it. Mount the Bourdon tube in one of
the positions shown in figure 17.
4. The arrow on the RAISE LEVEL dial under the
word FLOAT should point toward the displacer. If not,
remove the dial from the controller, turn it over, and
install it in the correct position.
5. For a controller/transmitter with an indicator assem-
bly, the arrow near the word FLOAT on the indicator
plate should point toward the displacer. If it does not,
remove the two screws (key 41, see detail of indicator
assembly in figure 19), turn the front plate (key 54) to
the side with the FLOAT arrow pointing toward the
displacer, and secure the plate with the screws.
6. Install the controller/transmitter according to the
next section.
Type 2500
25