The fan/pump is started by pressing [Auto On] button on the keypad and applying a start signal. The speed is
adjusted manually by pressing the [
▲
] or [
▼
] navigation keys on the keypad to a level where the feedback is
around the system set-point.
Note
It is not possible to run the motor at maximum or minimum speed, when manually adjusting the motor speed
due to the need of giving the motor a step in the speed during auto-tuning.
PID auto-tuning functions by introducing step changes whilst operating at a steady state and then monitoring
the feedback. From the feedback response, the required values for par.20-93
PID Proportional Gain and par.
20-94
PID Integral Time are calculated. par.20-95 PID Differentiation Time is set to value 0 (zero). par.20-81 PID
Normal/ Inverse Control is determined during tuning process.
These calculated values are presented on the keypad and the user can decide whether to accept or reject them.
Once accepted, the values are written to the relevant parameters and auto-tuning mode is disabled in par.
20-79
PID Autotuning. Depending on the system being controlled the time required to carry out auto-tuning
could be several minutes.
It is advised to set the ramp times in par.3-41
Ramp 1 Ramp up Time, par.3-42 Ramp 1 Ramp Down Time or par.
3-51
Ramp 2 Ramp up Time and par.3-52 Ramp 2 Ramp down Time according to the load inertia before carrying
out PID autotuning. If PID autotuning is carried out with slow ramp times, the auto-tuned parameters will typi-
cally result in very slow control. Excessive feedback sensor noise should be removed using the input filter
(parameter groups 6-** and 5-5*, Terminal 53/54 Filter Time Constant/Pulse Filter Time Constant #29/33) before
activating PID autotuning. In order to obtain the most accurate controller parameters, it is advised to carry out
PID autotuning, when the application is running in typical operation, i.e. with a typical load.
20-70 Closed Loop Type
Option: Function:
This parameter defines the application response. The default mode
should be sufficient for most applications. If the application response
speed is known, it can be selected here. This will decrease the time nee-
ded for carrying out PID autotuning. The setting has no impact on the
value of the tuned parameters and is used only for the autotuning se-
quence.
[0] * Auto
[1] Fast Pressure
[2] Slow Pressure
[3] Fast Temperature
[4] Slow Temperature
20-71 PID Performance
Option: Function:
[0] * Normal Normal setting of this parameter will be suitable for pressure control in
fan systems.
[1] Fast Fast setting would generally be used in pumping systems, where a faster
control response is desirable.
Parameter Description
194 TR200 Programming Guide
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