Changing Controller Action; Reset Adjustment; Rate Adjustment; Anti-Reset Windup (Suffix Letter F) Adjustment - Fisher 4195 KB Series Instruction Manual

4195KA, KB, and KC Series
W3439 / IL
Figure 4–2. Changing Controller Action
(4195KB and KC Series Controllers)
marked in percentages of process pressure required
to drive the controller from zero output to full output.
To adjust the proportional band, open the controller
cover and locate the proportional band adjustment (PB
ADJ) knob. Rotate the knob until the desired value is
opposite the line on the proportional band indicator
cover.

Changing Controller Action

To change the controller action from direct to reverse
or vice versa, loosen the screws on the proportional
band indicator cover. Lift the cover out as shown in
figure 4–2 and rotate the proportional band adjustment
to the desired action. Setting the proportional band to
the values in the white portion of the adjustment pro-
vides direct controller action; setting proportional band
in the black portion provides reverse controller action.
Bourdon Tube or Capsular Element Controllers for
Positive or Compound Pressure
For direct control action:
An increasing sensed pressure increases output pres-
sure.
For reverse control action:
An increasing sensed pressure decreases output pres-
sure.
Capsular Element Controllers for Vacuum Pressure
For direct control action:
An increasing sensed vacuum increases output pres-
sure.
For reverse control action:
4–2
An increasing sensed vacuum decreases output pres-
sure.
After changing the action, tighten the screws on the
proportional band indicator cover.

Reset Adjustment

To adjust reset, open the controller cover and locate
the RESET adjustment. Rotate the adjustment clock-
wise to decrease the minutes per repeat or counter-
clockwise to increase the minutes per repeat. Increas-
ing the minutes per repeat provides a slower reset
action.

Rate Adjustment

To adjust rate, open the controller cover and locate
the RATE adjustment. Rotate the adjustment clock-
wise to decrease the minutes (less rate action) or
counterclockwise to increase the minutes (more rate
action).
Anti-Reset Windup (suffix letter F)
Adjustment
If the arrow on the relief valve points toward the bot-
tom of the controller case, as shown in figure 4–1, the
valve opens with increasing controller output pressure.
If the arrow points in the opposite direction, the relief
valve opens with decreasing controller output pres-
sure. Differential relief pressure is factory set at 5 psig
(0.3 bar). Maximum relief pressure is 7 psig (0.5 bar).
The minimum is 2 psig (0.1 bar).
Turn the adjusting screw counterclockwise to increase
differential relief pressure, clockwise to decrease it.
Switching the Auto/Manual Station (suffix
letter E)
CAUTION
Switching the controller between auto-
matic and manual mode without balanc-
ing can disturb the process and cause
controller cycling.
Refer to figure 4–1 if the controller has the auto/manu-
al station (suffix letter E). To switch from automatic to
manual mode, or from manual to automatic, you must
first balance the manual output with the controller out-
put. Two balance methods are available to equalize
the manual output with the controller output.
To switch from automatic to manual mode, carefully
adjust the loader knob until the metal ball inside the
plastic tube moves into the switching zone. Then
move the automatic/manual switch to MANUAL. Turn
the loader knob clockwise to increase the controller
output or counterclockwise to decrease it.