Danfoss VLT AQUA Programming Manual page 182

2. Parameter Description
2
20-71 PID Output Change
Range:
0.10
20-73 Minimum Feedback Level
Range:
0.000
User
Units
20-74 Maximum Feedback Level
Range:
0.000
User
Units
20-74 Tuning Mode
Option:
[0]
[1]
20-79 PID Auto-Tuning
Option:
[0]
[1]
182
* [0.01 - 0.50]
[999999.999 - Value
of par. 20-74]
*
[Value of par. 20-73 -
999999.999]
*
*
Normal
Fast
* Disabled
Enabled
MG.20.O2.02 - VLT
steady state before logging data, thus leading to erroneous set-
tings. The setting has no impact on the value of the tuned
parameters and is used only for the Auto-tuning sequence.
Function:
This parameter sets the magnitude of step change during auto-
tuning. The value is a percentage of full speed. I.e. if maximum
par 4-13/4-14, Motor Speed High Limit
output frequency in
set to 50Hz, 0.10 is 10% of 50Hz, which is 5Hz. This parameter
should be set to a value resulting in feedback changes of be-
tween 10% and 20% for best tuning accuracy.
Function:
The minimum allowable feedback level should be entered here
in User units as defined in par 20-12. If the level falls below par
20-73, Auto-tuning is aborted and an error message will appear
on the LCP.
Function:
The maximum allowable feedback level should be entered here
in User units as defined in par 20-12. If the level rises above par
20-74, Auto-tuning is aborted and an error message will appear
on the LCP.
Function:
Normal
[0]: Suitable for pressure control in fan systems, espe-
cially where the pressure sensor may be some distance form the
fan.
Fast
[1]: Generally used in pumping systems, where a faster
control response is desirable.
Function:
This parameter starts the PID Auto-tuning sequence. Once the
Auto-tuning has successfully completed and the settings have
been accepted or rejected by the user, by pressing [OK] or
[Cancel] buttons on the LCP at the end of tuning, this parameter
is reset to [0] Disabled.
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VLT AQUA Drive Programming Guide
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