Anti-Reset Windup Valve (Suffix Letter F) Calibration - Emerson Fisher 4194HA Instruction Manual

Instruction Manual
D200156X012
18. Pressure the differential pressure unit or, if disconnected, position the process indicator to align with the left‐hand
edge of the set point indicator. The controller output should be within 0.14 bar (2 psig) of supply pressure.
19. If the controller does not perform as indicated in steps 13 through 18, the flapper is not correctly aligned. This may
occur because the output was not sufficiently stabilized in steps 8 through 12. Repeat steps 7 through 18.
20. Set the proportional band to 400 percent in the desired controller action. Replace the proportional band indicator
cover (key 36) and install the two machine screws (key 6). If link 1 was disconnected, reconnect link 1 to the drive
arm using the same hole connections.
21. If the controller has the external feedback option, disconnect the outside tubing which connects the external
feedback connection to the output connection.
22. For 4194HB and HC controllers with the anti‐reset windup option (suffix letter F), remove the two machine screws
(key 53), valve cover (key 51), and two O‐rings (key 52) installed in step 1 of this procedure. Install the differential
relief valve (key 55).
Anti‐Reset Windup Valve (suffix letter F) Calibration
Calibration for the anti‐reset windup valve to relieve on rising controller output pressure:
1. Plug the controller output connection or connect it to a pressure gauge if desired (open‐loop conditions must
exist).
2. Set the reset adjustment to 0.01 minute per repeat (wide open) and the rate adjustment (4194HC controllers only)
to the OFF position.
3. For a controller with manual set point, move the set point to 50 percent of the scale range. For a controller with
remote set point, adjust the remote set point pressure until the set point indicator is at 50 percent of the scale
range.
4. Adjust the proportional band to 100 percent DIRECT or REVERSE depending on the application requirements.
5. Refer to figure 3‐1 or figure 6‐1 (VIEW E, SUFFIX BF) for the location of the anti‐reset windup valve. For the anti‐reset
windup valve to relieve on rising controller output pressure, install the valve so the arrow on the valve points down.
If you must change the direction of the arrow, loosen the two mounting screws, pull the valve out, and reinstall with
the arrow, direction reversed. Tighten the two mounting screws.
6. Turn on the supply pressure to the recommended value shown in table 1‐4.
Note
Because of the high controller gain with the reset adjustment at 0.01 minute per repeat, the controller output will not balance
perfectly in the following step. If the controller output is stable for approximately 5 seconds, it is adequately balanced.
7. Increase the process differential pressure to the differential pressure unit until the controller output pressure is
balanced at 6 psig (for a 3 to 15 psig output range) or 12 psig (for a 6 to 30 psig output range).
8. Turn the reset adjustment to the CLOSED (4194HB controllers) or OFF (4194HC controllers) position.
9. Increase the process differential pressure until controller output pressure changes in small steps (approximately 0.5
psig). After each change in input, the controller output pressure should quickly change and then stabilize at the new
value.
10. Continue to affect the controller output pressure in 0.5 psi steps and check the output pressure after each step to
make sure that it stabilizes. At some point, the controller output will start to ramp upward to supply pressure with
no further change to the differential pressure input. Record the controller output pressure where this ramping
action begins because this is the point at which the anti‐reset windup valve has relieved.
11. To obtain the anti‐reset windup valve differential setting, calculate the difference between the original controller
output pressure in step 7 and the controller output pressure recorded in step 10.
4194HA, HB, HC Controllers
July 2018
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