Instruction Manual
D103292X012
C1 Controllers and Transmitters
March 2017
17
in effect, the time in minutes required for the controller to increase (or decrease) its output pressure by an amount
equal to a proportional increase (or decrease) caused by a change in set point or process pressure.
Adjustment: Anti-Reset Windup
The externally mounted differential relief valve can be mounted to relieve on increasing or decreasing output pressure.
Calibration
Calibration: Proportional-Plus-Reset Controllers
Unless otherwise indicated, key number locations are shown in figure 7.
Before starting this procedure:
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Provide a process pressure source capable of simulating the process pressure range of the controller.
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If an output pressure gauge is not provided, install a suitable pressure gauge for calibration purposes. The
controller must be connected open loop (Open loop: The controller output pressure changes must be dead
ended into a pressure gauge).
Note
C1P and C1B controllers with anti-reset windup are supplied with two O-rings (key 81), an anti-reset windup cover (key 80), and
two machine screws (key 82). Use these parts in the next step.
1. For C1P and C1B controllers with anti-reset windup record the direction of the arrow on the anti-reset windup
assembly (key 190, in figure 23). Remove the assembly and install the two O-rings (key 81), and cover (key 80)
supplied with the controller. Secure the cover with the two machine screws (key 82) provided.
3. Rotate the reset knob to 0.01 minutes per repeat (fastest setting).
4. Rotate the proportional band adjustment knob to 1.5 (15 percent proportional band).
5. Verify that the calibration adjuster screws (key 48) are at mid-position in the calibration adjuster (key 36) slots.
Depending upon the controller action, perform one or the other of the following procedures.
For reverse-acting controllers:
6. Apply an input pressure equal to the sensing element upper range value.
7. Rotate the pressure setting knob to the maximum value.
8. Adjust the nozzle (key 54) until the controller output pressure is between 0.6 and 0.7 bar (8 and 10 psig).
9. Apply an input pressure equal to the sensing element lower range value.
10. Rotate the pressure setting knob to the minimum value.
Note
When performing the span adjustment in step 11, do not watch the output gauge while changing the calibration adjuster. The
change in output is not a good indication of the change in span. While moving the calibration adjuster, the output pressure may