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4194A, B, and C Series
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. When the flapper is correctly aligned, set the pro-
portional band to 400 percent in the desired controller
action and replace the proportional band indicator cov-
er. If link 1 was disconnected, reconnect link 1 to the
input element using the hole noted in step 7.
21. For controllers with anti-reset windup (suffix letter
F), remove the two machine screws, valve cover and
two O-rings installed in step 1 of this procedure. Install
the anti-reset windup relief valve (key 55) with the ar-
row pointing in the direction recorded in step 1.
22. Set the proportional band to 400 percent in the
desired controller action. Replace the proportional
band indicator cover (key 36) and tighten the two
screws (key 6). Reconnect link number 1, if discon-
nected, to the same hole in the input element noted in
step 7.
Anti-Reset Windup Differential Relief
Valve (suffix letter F) Calibration
Calibration for the differential relief valve to relieve
on rising controller output pressure
1. Provide a means of measuring the controller output
pressure by connecting the controller output to a pres-
sure gauge (open-loop conditions must exist). Do not
apply supply pressure at this time.
2. Set the reset adjustment to 0.01 minutes per re-
peat (wide open) and the rate adjustment (4194C Se-
ries only) to OFF.
3. For a controller with manual set point, move the set
point indicator to the mid-scale mark on the process
scale. For a controller with remote set point, adjust the
remote set point pressure until the set point indicator
is at the mid-scale mark of the process scale.
4. Set the proportional band to 100 percent in either
the DIRECT or REVERSE action depending on the
application requirements.
5. Refer to figure 4-3 for the location of the anti-reset
windup differential relief valve. For the differential relief
valve to relieve on rising controller output pressure,
install the valve so the arrow on the valve points down.
To change the direction of the arrow, loosen the two
mounting screws, pull the valve out, and reinstall the
valve with the arrow pointing down. Tighten the two
mounting screws.
6. Provide a regulated supply pressure to the control-
ler. Do not exceed the normal operating pressure in
table 1-4.
4–8
Because of the high controller gain with
the reset adjustment at 0.01 minutes per
repeat, the controller output will not bal-
ance perfectly in the following step. If
the controller output is stable for
approximately 5 seconds, it is adequate-
ly balanced.
7. Increase the process differential pressure to the
controller until the controller output pressure balances
at 6 psig (0.4 bar) for a 3 to 15 psig (0.2 to 1.0 bar)
output range or 12 psig (0.8 bar) for a 6 to 30 psig (0.4
to 2.0 bar) output range.
8. Turn the reset adjustment to the CLOSED (4194B
Series) or OFF (4194C Series) position.
9. Increase the controller output pressure in small
steps (approximately 0.5 psig (0.04 bar)) by changing
the process differential pressure 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 0.5 psi (0.04 bar) steps and check the output pres-
sure after each step to make sure it stabilizes. At
some point, the controller output will start to ramp up-
ward to supply pressure with no further change to the
controller input or set point. Record the controller out-
put pressure where this ramping action begins be-
cause this is the point at which the differential relief
valve has relieved.
11. To obtain the differential relief 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
pressure by turning the differential relief valve adjust-
ment screw, shown in figure 4-3. Turn the screw clock-
wise to decrease the differential pressure or counter-
clockwise to increase the differential pressure. The
differential relief valve is set at the factory to relieve at
approximately 5 psi (0.4 bar) differential pressure.
13. Repeat steps 7 through 12 until the required dif-
ferential pressure is obtained.
Calibration for the differential relief valve to relieve
on falling controller output pressure
1. Provide a means of measuring the controller output
pressure by connecting the controller output to a pres-
sure gauge (open-loop conditions must exist). Do not
apply supply pressure at this time.
2. Set the reset adjustment to 0.01 minutes per re-
peat (wide open) and the rate adjustment (4194C Se-
ries) to the OFF position.
Note
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