WEBVISION™
95-7769—01
80
UV PID settings
Use Table 60 to configure the Unit Ventilator PID settings.
Purpose
Adjust PID (Proportional Integral Derivative) control
parameters for the Unit Ventilator Controller.
Mode
Configuration can be performed with the wizard Off-line or
On-line.
CAUTION
Equipment Damage Possible
Can cause short cycling of compressors or wide
swings in space temperature and excessive
overdriving of modulating outputs.
If a large or frequent change to the PID control
parameters is made, it is possible to cause
equipment problems such as short cycling
compressors (if the stage minimum run times were
disabled). Other problems that can occur include
wide swings in space temperature and excessive
overdriving of modulating outputs.
The default values provide proper control for most
applications. If the PID parameters require adjustment away
from these values, use caution to ensure that equipment
problems do not arise. If any change to the PID control
parameters is made, the adjustments should be gradual. After
each change, allow the system to stabilize so the effects are
accurately observed. Make further refinements as needed
until the system is operating as desired.
If the default values are changed and you want to reset them,
add a second Unit Ventilator Controller to the subnet, record
then re-enter the default PID values to the first Unit Ventilator.
Procedure
1.
Click the
PID
button on the left pane to open the
PID
Configuration
page.
2.
Enter information into available fields.
3.
Click
Commit
to save the settings or
Reset
to revert to
the last saved settings.
4.
Click
Next
to display the
Wiring Assignment
page or
Back
to display the
Miscellaneous Parameters
Configuration
page.
CAUTION
Equipment Damage Possible
Adjustments may cause large over or undershooting
of setpoint. The default values provide proper control
for most systems.
UV PID Settings fields
Override Priority
Set the priority scheme for the Bypass
override function. You can select one of
the following options:
• Last
- Whichever was last to occur;
either the button was pushed or the
network signal arrived.
• Net
- The network signal always takes
precedence over the push button.
This field is enabled if Override Type is
Normal or Bypass Only.
Bypass Time
Set the time period for a bypass override
event. Value ranges from 0 through 1080
minutes. Enabled if Override Type is
Normal or Bypass Only.
Max Da Temp
Setpoint
Value ranges from 65 to 135 °F
(18 to 57 °C). Enabled if you selected a
discharge air temperature sensor. This
setting is only used if Cascade Control is
enabled.
Min. Da Temp
Value ranges from 0 to 60 °F
(-18 to 16 °C). Enabled if you selected a
discharge air temperature sensor. This
setting is used in Cascade Control, and as
the Low Limit alarm threshold for
discharge temp.
Setpoint Knob
Type
Select Relative (plus or minus up to 10
degrees from the current actual setpoint
set on the Zone Options page), or
Absolute_Middle (the Wall Module’s knob
sets the midpoint between the heat and
cool current actual setpoints).
You can select one of the following
options:
•
Unused
•
Offset
•
Absolute
Table 59. Unit Ventilator Miscellaneous Settings.
Name
Definition
Table 60. Unit Ventilator PID Settings.
Name
Definition
Cooling
Throttling
Range
Throttling Range or Proportional Gain
Determines what impact the error has on the
output signal.
Decreasing the Throttling Range amplifies the
effect on the error, that is, for a given error (the
difference between the measured space
temperature and the current actual space
temperature setpoint), a small Throttling Range
causes a higher output signal value.
Enter the range in degrees: 2 to 30 °F
(-17 to -1 °C]).
