Emerson Fisher 4194HA Instruction Manual page 58

4194HA, HB, HC Controllers
July 2018
26. Position the proportional band knob, nozzle pivot, and set point beam assembly on frame. Install the relay nozzle
tubing nut loosely into frame manifold while positioning the nozzle in the center of the flapper as shown in
figure 5‐11.
27. Install the washer (key 20) on the screw (key 19).
28. Install the screw (key 19) through the frame (key 3) and into the relay nozzle tubing assembly (key 18). Tighten the
screw. Be sure the nozzle remains centered on the flapper with the set point beam assembly slid snugly towards the
relay nozzle tubing assembly.
29. Install washer (key 20) on screw (key 19).
30. Install the screw (key 19) through the frame (key 3) into the set point pivot assembly (key 23). Do not tighten.
31. Slide the set point pivot assembly (key 17) toward the set point beam until the cone lightly contacts the set point
beam and tighten the screws. The proportional band knob should fall freely when the controller is in the upright
position. If it does not, reposition the set point pivot assembly (key 17).
32. Tighten the relay nozzle tubing nut (key 18). Apply full supply pressure and check for leaks. Disconnect the supply
pressure.
33. Install the set point beam bias spring (key 28) into frame (key 3) bore and onto spring seat on the set point beam
assembly (key 23).
34. Attach link 3 to the set point beam assembly.
Note
The following procedure (steps 35 through 45) adjusts link 4 so it will always be in compression to eliminate possible instability
due to lost motion.
35. For controllers with reset or rate adjustments (4194HB or 4194HC controllers), disconnect the supply pressure and
adjust the rate to OFF. Controller output must be 0 bar (0 psig). Set the reset adjustment to 0.01 minutes per repeat
and wait 30 seconds. Then, turn the reset adjustment to CLOSED (4194HB) or OFF (4194HC) position.
36. Apply proper supply pressure to the controller and provide an accurate means of measuring the controller output
pressure.
37. Adjust the proportional band to 5 percent REVERSE (reverse action) and adjust the set point to the maximum value
on the process scale.
38. With link 1 still disconnected, tape the process indicator at the minimum process scale value (the last mark on the
left side of the scale). The output pressure should be within 0.07 bar (2 psig) of the supply pressure. If not, adjust
flapper leveling screw number 1 until the output is within 0.14 bar (2 psig) of supply pressure.
39. Loosen the two adjustment screws on link 4 (see figure 5‐5) and connect the link to the bellows bracket (key 31),
allowing the link to find its free length.
40. Tighten the two adjusting screws on link 4 (see figure 5‐5).
41. Raise link 4 out of the hole in the bellows bracket (key 31) and ensure it drops back into the hole under its own
weight. If not, repeat steps 39 and 40.
42. Perform steps 20 through 26 in the maintenance procedure for the proportional band adjustment knob, nozzle
assembly, and set point beam assembly.
43. Remove the tape from the process indicator and reconnect link 1 to the drive arm. For 4194HB and 4194HC
controllers (controllers with reset), turn the reset adjustment to 0.01.
44. Install the controller assembly in the case and cover.
45. Refer to the process indicator zero‐and‐span adjustment and flapper alignment procedures in the Maintenance
section.
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Instruction Manual
D200156X012