Fisher 4195 KB Series Instruction Manual page 42

LOCKING
NUT
SCREW AND WASHER
(KEYS 19 AND 20)
NOTES:
1 SCREW INSERTED INTO THE ADJUSTABLE SET POINT PIVOT ASSEMBLY.
2
SCREW INSERTED INTO THE RELAY NOZZLE TUBING ASSEMBLY.
W4195 / IL
Figure 5–6. Adjustable Set Point Pivot Assembly
Locking Nut Location
der its own weight when pivoted upward. Also, main-
tain a minimum side play between the adjustable set
point pivot assembly and the nozzle tubing assembly.
Tighten the locking nut.
31. At the frame manifold (key 135), tighten the nut
that secures the tubing from the relay nozzle tubing
assembly (key 18). Apply full supply pressure with the
nozzle capped and check for leaks. Remove supply
pressure.
32. Install the set point beam bias spring (key 28) into
the frame bore and onto the spring seat on the set
point beam assembly.
33. Attach link 3 to the set point beam shoe as shown
in figure 5–3.
34. For controllers with reset or rate adjustment
(4195KB or 4195KC Series), turn the reset adjustment
to the CLOSED (4195KB) or OFF (4195KC) position.
Set the rate adjustment to the OFF position.
The controller output must be 0 psig (0 bar). To be
sure the controller output is 0 psig (0 bar), remove
supply pressure, set the reset adjustment to 0.01 min-
utes per repeat and wait 30 seconds; then, turn the
reset adjustment to the CLOSED position (4195KB) or
to the OFF position (4195KC).
35. Apply the correct supply pressure (refer to table
1–6) to the controller and provide an accurate means
of measuring the controller output pressure.
36. Perform the appropriate process indicator zero
and span calibration procedure and, if necessary, the
remote set point zero and span calibration procedure
ADJUSTABLE SET POINT
PIVOT ASSEMBLY
SCREW AND WASHER
2 (KEYS 19 AND 20) 1
4195KA, KB, and KC Series
in section 3 or 4. When calibration is complete, contin-
ue with step 37 below.
The following procedure (steps 37
through 43) matches the process point-
er motion to the set point indicator mo-
tion so the controller will control at set
point at all positions on the process
scale.
37. Set the proportional band to 40 percent in RE-
VERSE or DIRECT depending on the desired control-
ler action.
38. Adjust the set point to the lower limit on the pro-
cess scale.
39. Disconnect link 1 from the input element, noting
the hole from which it is removed, for capsular input
elements, and tape the process pointer to the lower
limit on the process scale. The output pressure may
be anywhere between 3 to 15 psig (0.2 to 1.0 bar) for
a 3 to 15 psig (0.2 to 1.0 bar) output signal range or
between 6 to 30 psig (0.4 to 2.0 bar) for a 6 to 30 psig
(0.4 to 2.0 bar) output signal range. If the output is not
within the specified range, adjust the flapper leveling
screw nearest the nozzle until the output is within the
range specified. Record the controller output pressure.
40. Adjust the set point to the upper limit on the pro-
cess scale.
41. Remove the tape and move the process pointer
until the controller output equals the pressure recorded
in step 39. Note the process pressure indication.
42. The process pressure indication should be within
2 percent of the upper limit on the process scale.
If the process pressure indication in step 41 is greater
than the upper limit of the process scale by 2 percent,
loosen the shoe adjustment screws (key 30), shown in
figure 5–3, and move the set point beam shoe (key
29) slightly away from the center of the flapper assem-
bly.
If the process pressure indication in step 41 is less
than the upper limit of the process scale by 2 percent,
loosen the shoe adjustment screws (key 30), shown in
figure 5–3, and move the set point beam shoe (key
29) slightly toward the center of the flapper assembly.
43. Repeat steps 38 through 42 until the error is less
than 2 percent of process scale span at the upper limit
of the process scale.
44. Remove the tape from the process pointer and
reconnect link 1 to the input element. If the controller
has a capsular input element, be sure to reconnect link
1 in the same hole noted in step 39.
45. Position the controller assembly in the case and
start, but do not tighten the nine mounting screws.
Note
5–9