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 needed for carrying out PID
autotuning. The setting has no impact
on the value of the tuned parameters
and is used only for the autotuning
sequence.
[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.
20-72 PID Output Change
Range:
Function:
0.10
*
[0.01 -
0.50 ]
This parameter sets the magnitude of step
change during autotuning. The value is a
percentage of full speed. I.e. if maximum
output frequency in
4-14 Motor Speed High Limit [Hz]
is
set to 50 Hz, 0.10 is 10% of 50 Hz, which is 5
Hz. This parameter should be set to a value
resulting in feedback changes of between 10%
and 20% for best tuning accuracy.
20-73 Minimum Feedback Level
Range:
Function:
-999999
ProcessCtrlUnit
*
[ -999999.999 -
par. 20-74
ProcessCtrlUnit]
The minimum allowable
feedback level should be
entered here in User units
as defined in
20-12 Reference/Feedback
Unit
. If the level falls below
, autotuning is
aborted and an error
message appears in the
LCP.
20-74 Maximum Feedback Level
Range:
Function:
999999
ProcessCtrlUnit
*
[ par. 20-73 -
999999.999
ProcessCtrlUnit]
The maximum allowable
feedback level should be
entered here in User units
as defined in
20-12 Reference/Feedback
Unit
. If the level rises
above
, autotuning
is aborted and an error
message appears in the
LCP.
20-79 PID Autotuning
Option:
Function:
This parameter starts the PID autotuning
sequence. Once the autotuning has successfully
completed and the settings have been accepted
or rejected by the user, by pressing [OK] or
[Cancel] at the end of tuning, this parameter is
reset to
[0] Disabled
.
[0]
*
Disabled
[1]
Enabled
3.15.6 20-8* PID Basic Settings
This parameter group is used to configure the basic
operation of the frequency converter’s PID Controller,
including how it responds to a feedback that is above or
below the setpoint, the speed at which it first starts
functioning, and when it will indicate that the system has
reached the setpoint.
20-81 PID Normal/Inverse Control
Option:
Function:
[0]
Normal
Normal
[0] causes the frequency converter’s output
frequency to decrease when the feedback is
greater than the setpoint reference. This is
common for pressure-controlled supply fan and
pump applications.
[1]
*
Inverse
Inverse
[1] causes the frequency converter’s output
frequency to increase when the feedback is greater
than the setpoint reference. This is common for
temperature-controlled cooling applications, such
as cooling towers.
Parameter Description
VLT
®
Refrigeration Drive Programming Guide
118
MG16H102 - VLT
®
is a registered Danfoss trademark
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