Replacing The Supply, Proportional, Reset, Reset Valve, And Relief Tubing Assemblies - Emerson Fisher 4194HA Instruction Manual

Instruction Manual
D200156X012
4. For controllers with reset (4194HB controllers) or rate and reset (4194HC controllers), disconnect the supply
pressure and then adjust the rate (4194HC controllers, only) to OFF. The controller output pressure must be 0 bar.
Adjust the reset to 0.01 minutes per repeat and wait 30 seconds. Then, turn the reset adjustment to the CLOSED
(4194HB controllers) or OFF (4194HC controllers) position.
The controller output must be 0 bar. To be sure the controller output is at 0 bar, remove supply pressure, set the
reset adjustment to 0.01 minutes per repeat and wait 30 seconds; then turn the the reset adjustment to the
CLOSED (4194HB controllers) or OFF (4194HC controllers) position.
5. Adjust the proportional band to 5 percent REVERSE (reverse action) and move the set point adjustment indicator to
100 percent of the scale range.
6. Apply the correct supply pressure to the controller. The output of the controller should be within 0.14 bar (±2 psig)
of the supply pressure. If not, adjust the flapper leveling screw number 1 (figure 3‐1) until the output is within 0.14
bar (±2 psig) of supply pressure.
7. Loosen the two adjusting screws on link 4. Connect the free end of the link to the bellows bracket and allow the link
to find its free length.
8. Tighten the two adjusting screws on the link.
9. The process indicator should indicate 50 percent of the process scale. If not, loosen the screws in link 1 and adjust
the indicator to 50 percent, ±3 percent, of scale span. Tighten the two screws.
10. Perform the controller calibration procedure and flapper alignment procedure.

Replacing the Supply, Proportional, Reset, Reset Valve, and Relief Tubing Assemblies

Note
Before starting the following procedure, remove the controller from the case. Perform steps 1 through 7 of the Replacing the
Differential Pressure Unit procedure. Then, perform steps 1 and 2 of the Replacing the Case and Cover procedure.
Refer to figure 6‐1 for key number locations.
1. Remove the nuts holding the supply gauge tubing assembly (key 39) and the proportional tubing assembly (key 40)
to the frame. Remove the tubing.
2. Install the replacement tubing assemblies.
3. Set the reset adjustment to 0.01 (4194HB and HC controllers) and set the rate adjustment to OFF (4194HC
controllers).
4. Apply the correct supply pressure and check for leaks. Then, remove pressure.
5. Install the controller assembly into the case. Slide the controller assembly down and make sure the O‐rings (key 7)
form a proper seal at the pressure connections. Hold the frame in place.
6. Install and tighten the nine self‐tapping screws (key 38) into the frame.
7. Perform the process indicator zero‐and‐span adjustment and flapper alignment procedure in the Maintenance
Calibration section.
8. Mount the assembled controller on a pipestand as described in the Installation section. Connect supply, output, and
process differential pressure piping to controller/differential pressure unit.
4194HA, HB, HC Controllers
July 2018
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