Cutler-Hammer - Eaton Canada

AF93/IS903 Parameter Descriptions
USING THE PARAMETERS
Remote Function (Cont.)
Since the PI Regulator software works best when
the analog feedback is scaled to the full range, we
recommend that the Minimum Analog Reference
(parameter 8) be set to 0% and the Maximum
Analog Reference (parameter 9) be set to 100%
(for direct acting control). In applications that
require inverse control, set the Minimum Analog
Reference parameter to 100% and the Maximum
Analog Reference parameter to 0%.
Using ÒMIN POT REFÓ and ÒMAX POT REFÓ, the
operating band can be adjusted for the specific
application. In this example for a desired setpoint
of 10 psi and a maximum range of 8 to 12 psi, the
operator would set Minimum Potentiometer
Reference and Maximum Potentiometer
Reference to the equivalent percentages of these
values.
Pressure
Level
PI Setpoint
Cutler-Hammer
PI
Controller
AF93/IS903
We recommend that, for most applications, you
set the initial value of the Integral Gain (parameter
24) to 10000 and Proportional Gain (parameter
25) to 10000. Since these values are not Run
Locked (can be changed while the system is
running) you can adjust them (in 1000 unit
intervals) while you observe its operation. To
increase or decrease the response time to
changes in feedback value, you might want to
change the value of Integral Gain. To control the
amount of under and overshoot, you might want to
adjust the Proportional Gain. Note that some types
of systems, such as HVAC control, might not need
much proportional gain.
Feedback (Duct Pressure)
PI Control Application Example
Figure 4-1
HVAC
ETN-HVACPI
Pressure
Transducer
AF93/IS903 Instruction Manual
4-19