VLT
®
FCD Series
Programming, FCD
300
feedback signal varies by a higher frequency than 1.6
Hz, it will be dampened by the lowpass filter.
445 Flying start
(FLYINGSTART)
Value:
✭
Off (DISABLE)
[0]
OK - same direction
(OK-SAME DIRECTION)
[1]
OK - both directions
(OK-BOTH DIRECTIONS)
[2]
DC brake and start
(DC-BRAKE BEF. START)
[3]
Function:
This function makes it possible to
’
catch
’
a rotating
motor shaft, which is no longer controlled by the
frequency converter, e.g. because of a mains
drop-out. The function is activated each time a start
command is enabled. For the frequency converter
to be able to
’
catch
’
the rotating motor shaft, the
motor speed must be lower than the frequency
that corresponds to the frequency in parameter
202
Output frequency, high limit, f
MAX
.
Description of choice:
Select
Disable
[0] if this function is not required.
Select
OK - same direction
[1] if the motor shaft
is only able to rotate in the same direction when
cutting in.
OK - same direction
[1] should be
selected if in parameter 200
Output frequency range
a selection has been of
Clockwise only
.
Select
OK - both directions
[2] if the motor is able
to rotate in both directions when cutting in.
Select
DC brake and start
[3] if the frequency converter
is to be able to brake the motor using the DC brake
first, followed by start. It is assumed that parameters
126-127/132
DC brake
are enabled. In the case
of higher
’
Windmilling
’
(rotating motor) effects, the
frequency converter is not able to
’
catch
’
a rotating
motor without selecting
DC brake and start
.
Limitations:
-
Too low inertia will lead to load acceleration, which
can be dangerous or prevent correct catching of a
rotating motor. Use the DC brake instead.
-
If the load is driven, e.g. by
’
Windmilling
’
(rotating motor) effects, the unit may cut
out because of overvoltage.
-
Flying start does not work at lower values
than 250 rpm.
451 Speed PID feedforward factor
(FEEDFORWARD FACT)
Value:
0 - 500 %
✭
100 %
Function:
This parameter is only active if in parameter 100
Configuration
the selection made is
Speed regulation,
closed loop
. The FF function sends a larger or smaller
part of the reference signal outside the PID controller
in such a way that the PID controller only has an
influence on part of the control signal. Any change
to the set point will thus have a direct effect on the
motor speed. The FF factor provides high dynamism
when changing the set point and less overswing.
Description of choice:
The required % value can be selected in the interval
f
MIN
- f
MAX
. Values over 100 % are used if the
set point variations are only small.
452 Controller range
(PID CONTR. RANGE)
Value:
0 - 200 %
✭
10 %
Function:
This parameter is only active if in parameter
100
Configuration
the selection made is
Speed
regulation, closed loop
.
The controller range (bandwidth) limits the output from
the PID controller as a % of motor frequency f
M,N
.
Description of choice:
The required % value can be selected for motor
frequency f
M,N
. If the controller range is reduced the
speed variations will be less during initial tuning.
455 Frequency range monitor
(MON. FREQ. RANGE)
Value:
Disable
[0]
✭
Enable
[1]
Function:
This parameter is used if warning 35
Out of frequency
range
must be turned off in the display in process
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.04.B7.02 - VLT is a registered Danfoss trademark
75
