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
inpar. 4-13
Motor Speed High Limit [RPM]
/
par. 4-14
Motor Speed High Limit [Hz]
is 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 between 10% and 20% for best tuning
accuracy.
20-73 Minimum Feedback Level
Range:
Function:
-999999.000
ProcessCtrlU-
nit
*
[Applica-
tion
dependant]
The minimum allowable feedback
level should be entered here in User
units as defined in
par. 20-12
Reference/Feedback Unit
. If
the level falls below
par. 20-73
Minimum Feedback Level
,
autotuning is aborted and an error
message will appear on the LCP.
20-74 Maximum Feedback Level
Range:
Function:
999999.000
ProcessCtrlU-
nit
*
[Applica-
tion
dependant]
The maximum allowable feedback
level should be entered here in User
units as defined in
par. 20-12
Reference/Feedback Unit
. If
the level rises above
par. 20-74
Maximum Feedback Level
,
autotuning is aborted and an error
message will appear on 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] buttons on
the LCP at the end of tuning, this parameter is reset
to [0] Disabled.
[0]
*
Disabled
[1]
Enabled
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 applica-
tions.
[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.
20-82 PID Start Speed [RPM]
Range:
Function:
Applica-
tion
depend-
ent
*
[Applica-
tion
depend-
ant]
When the frequency converter is first
started, it initially ramps up to this output
speed in Open Loop Mode, following the
active Ramp Up Time. When the output
speed programmed here is reached, the
frequency converter will automatically
switch to Closed Loop Mode and the PID
Controller will begin to function. This is
useful in applications in which the driven
load must first quickly accelerate to a
minimum speed when it is started.
NOTE
This parameter will only be visible
if par. 0-02
Motor Speed Unit
is set
to [0], RPM.
20-83 PID Start Speed [Hz]
Range:
Function:
Applica-
tion
depend-
ent
*
[Applica-
tion
depend-
ant]
When the frequency converter is first
started, it initially ramps up to this output
frequency in Open Loop Mode, following
the active Ramp Up Time. When the
output frequency programmed here is
reached, the frequency converter will
automatically switch to Closed Loop Mode
and the PID Controller will begin to
function. This is useful in applications in
which the driven load must first quickly
accelerate to a minimum speed when it is
started.
NOTE
This parameter will only be visible
if par. 0-02
Motor Speed Unit
is set
to [1], Hz.
20-93 PID Proportional Gain
Range:
Function:
0.50
*
[0.00 - 10.00 ]
How to Programme the Frequ...
VLT
®
HVAC Drive Operating Instructions
88
MG.11.AD.02 - VLT
®
is a registered Danfoss trademark
7
7