Setting The Control Constants - Sinclair SCMI-01.4 User Manual

Off mode
In this mode, the output to control the indoor unit fan speed is not used

Setting the Control Constants

This menu allows you to set the control constants of the SCMI-01.4 module. Press the
ENTER key to enter the setting menu and use the ▼/▲ keys to select the Reg.cons menu.
After opening this menu, you can select and set the control constants.
Time con
Prop.con
Int.cons
Der.cons
Time constant
It determines the time period to perform the control and can be set from 10 to 999 sec. The
default value of the time constant is 30 seconds.
Proportional constant
It has a basic effect on the control process. The smaller proportional constant, the minor
interventions of the controller in the period given by the time constant. The default value is 35
and can be set from 0 to 999.
Integral constant
It allows to reach the minimum deviation of the regulation. Use caution when adjusting the
integral constant. If this constant is too high, the controlled system may be unstable and
prone to oscillation. The default value is 0 and can be set from 0 to 999.
Derivative constant
It determines, how the rate of the changes of the controlled variable effects the control
process. At higher derivative constant the system will be more responsive to the changes
and will counteract these changes. The default value is 60 and can be set from 0 to 999.
How to set the control constants
Characteristics of the controlled system must be considered when adjusting the control
constants. According to the rate of change of the controlled variable, the time constant must
be set first. The time constant should be generally at least twice the time it takes, when the
change of the desired value, set on the control module, starts to show in the system output.
It is not recommended to set the time constant value lower than about 30 seconds. The value
of the proportional constant affects the control accuracy and also the influence of the
derivative and integral constants on the controlled process. If you cannot achieve the desired
value with the required minimum deviation, it is necessary to increase the proportional
constant. It is also necessary to monitor the deviation between the desired and actual value
and adjust the derivative constant according to this deviation. If the system responds too fast
to the interventions of the controller and there is overshooting of the controlled variable, it is
necessary to increase the derivative constant. If the system cannot reach the desired
minimum deviation from the desired value for a long time, it is necessary to carefully increase
the integral constant. Settings of the control constants for the given operation mode of control
module may need to be adjusted and adapted to the new conditions if the mode is changed.
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Setting the time constant of the module.
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Setting the proportional constant of the module.
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Setting the integral constant of the module.
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Setting the derivative constant of the module.
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