Filter
Top Products
39NetworkAIR FM DX 60 Hz Operation, Maintenance, and Troubleshooting
6. Note the time, in minutes, between the peaks of the oscillations. This is the Ultimate Period, P
U.
7. Note the value of the proportional constant. This is the Ultimate Gain, G
U.
8. Compute the PID constants using the table below. Select the type of control from the rows of the
table and use the equations in the columns to compute the values for each constant.
9. Set each constant according to these calculations.
You may need to further tune the PID loops in the following ways to account for changes in the room
load:
Humidification sensitivity
Path: Main > Setup > System # > System Config > Humid. Sensitivity
Humid. Sensitivity.
The humidifier sensitivity band is the percentage of relative humidity below the
humidify setpoint at which the humidifier operates at full output.
Control
Method
Proportional Integral Derivative
P 0.5*G
U
––
P + I 0.45*G
U
0.54*G
U
/P
U
–
P + I + D 0.6*G
U
1.2 * G
U
/P
U
0.075*G
U
*P
U
Loop Behavior PID Tuning Correction
Slow response to temperature/humidity
changes
Decrease the proportional multiplier or increase the
derivative multiplier.
Over-cooling/Under-cooling after changes in
the room load or changes in setpoint
Increase the derivative or the proportional multipliers.
Environmental temperature/humidity never
reaches the setpoint
Increase the integral setting.
Over-cooling/Under-cooling on constant
room load
Decrease the integral multiplier.
Humid. Sensitivity:
2 %RH
na0434a