Fisher 4195 KB Series Instruction Manual page 51

4195KA, KB, and KC Series
ALIGNED
W3443-1 / IL
7. Perform the controller calibration procedures and, if
necessary, the appropriate remote set point calibration
procedure in section 3 or 4.
Replacing Bourdon Tube Controller Link 2
1. Remove the two screws (key 6), and lift off the pro-
portional band indicator cover (key 36).
2. Disconnect link 2 from the process pointer and
from the flapper assembly (key 11). Remove the link.
3. Install the replacement link with the screw head
nearest the process pointer as shown in figure 5–13.
Connect the link to the process pointer only.
4. The process pointer should be aligned with the
pointer subassembly as shown in figure 5–15. If not,
loosen the zero adjustment locking screw and adjust
the process pointer zero adjustment to align the pro-
cess pointer and pointer subassembly. Tighten the
zero adjustment locking screw.
5. Move the set point indicator, either manually or with
the remote set point pressure, to the process scale
lower limit and set the proportional band to 5 percent
REVERSE. The nozzle should not be touching the
flapper. If it is, adjust flapper leveling screw 1 (the
screw nearest the nozzle) until clearance is obtained.
6. Disconnect link 1 from the Bourdon tube and
manually position the process pointer to the process
scale upper limit. Tape the pointer in this position.
5–18
Figure 5–15. Process Pointer Alignment
7. Adjust the length of link 2 (by turning the adjusting
screw clockwise to increase the length or counter-
clockwise to decrease the length) so that the pin on
the end of the link is approximately one-half of its di-
ameter short of aligning with the hole in the flapper
assembly as shown in figure 5–11. This adjustment
provides the proper tension on the link to eliminate lost
motion.
8. Connect link 2 to the flapper assembly.
9. Remove the tape from the process pointer and re-
connect link 1 to the Bourdon tube.
10. Perform the controller calibration procedures and,
if necessary, the appropriate remote set point calibra-
tion procedure in section 3 or 4.
Replacing Bourdon Tube Controller Link 3
1. Remove the two screws (key 6), and lift off the pro-
portional band indicator cover (key 36).
2. Disconnect link 3 from the set point indicator and
the set point beam assembly (key 23).
3. Adjust the replacement link to the same length as
the link removed.
4. Install the replacement link with the screw head
toward the set point beam assembly as shown in fig-
ure 5–13.
5. Check that the set point beam bias spring (key 28)
is correctly located in the frame bore and the spring
ZERO ADJUSTMENT MISALIGNED
LOCKING SCREW
W3475-1 / IL
FINE ZERO
ADJUSTMENT