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

4194HA, HB, HC Controllers
July 2018
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 indicator 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 in either the DIRECT or REVERSE action depending on the application
requirements.
5. Refer to figure 3‐1 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 2.0 bar (6 psig) [for a 0.2 to 1.0 bar (3 to 15 psig) output range] or 0.8 bar (12 psig) [for a 2.0 to 4.0 bar
(6 to 30 psig) output range].
8. Turn the reset adjustment to the CLOSED (4194HB controllers) or OFF (4194HC controllers) position.
9. Increase the controller output pressure in small steps [approximately 0.04 bar (0.5 psig]) by changing the input to
the differential pressure unit or by changing the controller set point. After each change in differential pressure or set
point, the controller output pressure should quickly change and then stabilize at the new value.
10. Continue to change the controller output pressure in 0.04 bar (0.5 psi) steps and check the output pressure after
each step to make sure it stabilizes. At some point, the controller output will start to ramp upward to supply
pressure with no further change to the controller input or set point. 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.
12. If the differential pressure calculated in step 11 is incorrect for the application, adjust the differential by turning the
anti‐reset windup valve adjustment screw (figure 3‐1). Decrease the differential pressure by turning the screw
clockwise. Increase the differential pressure by turning the screw counterclockwise. The anti‐reset windup valve is
set at the factory at approximately 0.4 bar (5 psi) differential pressure.
13. Repeat steps 7 through 12 until the required differential pressure is obtained.
Calibration for the anti‐reset windup valve to relieve on falling 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.
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Instruction Manual
D200156X012