LX Series Unit Ventilator Controller User's Guide
76
PID Configuration
The Unit Ventilator Controller uses as many as five PID Loops to control the space
temperature, discharge temperature, CO
2
level, and humidity.
Table 18 applies to the space temperature, discharge temperature, CO
2
level, and
humidity loops.
Table 18: PID Configuration Parameters
Field
Description
Proportional Gain
Enter the gain per unit of the error.
Integral Gain
Enter the gain per unit of the error.
Integral Time
Enter the error repetitively sampled, and the integral gain is added to the
output. The period of time between samples is the integral time. Enter the
integral time for your process.
Derivative Gain
Enter the gain per unit of the error.
Derivative Time
Enter the derivative time–the time between two samples of the error. The
two samples are compared to find the change in the error.
Deadband
Enter a number to define the size of the deadband. The deadband is a
range of values symmetrical about the setpoint. See the
section for more information.
Use Supply Air
Temperature Only
for Limitation
Allows the Unit Ventilator Controller to control the unit with the room
demand, and limits the discharge temperature between the minimum and
maximum discharge temperature.
If this option is unchecked, the Unit Ventilator Controller tries to maintain
the calculated discharge temperature setpoint. The discharge setpoint is
calculated with a linear equation between the minimum and maximum
discharge air temperature and the space PID loops.
Figure 34: The PID Configuration Screen
