Danfoss VLT FC 103 Programming Manual page 119

Parameter Description
20-70 Closed Loop Type
Option:
3 3
[0] Auto
*
[1] Fast Pressure
[2] Slow Pressure
[3] Fast Temperature
[4] Slow Temperature
20-71 PID Performance
Option:
[0] Normal Normal setting of this parameter will be suitable
*
[1] Fast
20-72 PID Output Change
Range:
0.10 [0.01 -
*
0.50 ]
20-73 Minimum Feedback Level
Range:
-999999
ProcessCtrlUnit
118
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.
Function:
for pressure control in fan systems.
Fast setting would generally be used in pumping
systems, where a faster control response is
desirable.
Function:
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 4-13 Motor Speed High
Limit [RPM]/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.
Function:
[ -999999.999 - The minimum allowable
par. 20-74 feedback level should be
*
ProcessCtrlUnit] entered here in User units
as defined in
20-12 Reference/Feedback
Unit. If the level falls below
20-73 Minimum Feedback
Level, autotuning is
aborted and an error
message appears in the
LCP.
MG16H102 - VLT
®
VLT Refrigeration Drive Programming Guide
20-74 Maximum Feedback Level
Range:
999999
ProcessCtrlUnit
20-79 PID Autotuning
Option:
[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:
[0] Normal Normal [0] causes the frequency converter's output
[1] Inverse Inverse [1] causes the frequency converter's output
*
®
is a registered Danfoss trademark
Function:
[ par. 20-73 - The maximum allowable
999999.999 feedback level should be
*
ProcessCtrlUnit] entered here in User units
as defined in
20-12 Reference/Feedback
Unit. If the level rises
above 20-74 Maximum
Feedback Level, autotuning
is aborted and an error
message appears in the
LCP.
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.
Function:
frequency to decrease when the feedback is
greater than the setpoint reference. This is
common for pressure-controlled supply fan and
pump applications.
frequency to increase when the feedback is greater
than the setpoint reference. This is common for
temperature-controlled cooling applications, such
as cooling towers.