American Power Conversion DX Benutzerhandbuch

NetworkAIR 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, PU.
7. Note the value of the proportional constant. This is the Ultimate Gain, GU.
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

0.5*GU

–

P + I

0.45*GU

0.54* GU/PU

–

P + I + D

0.6*GU

1.2 * GU/PU

0.075*GU*PU

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

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