FCM 300 Series
61
MG.03.B6.02 - VLT is a registered Danfoss trademark
✭
=
factory setting. ( ) = parameter window text. [ ] = value for use in communication via serial communication port
Special functions
Description of choice:
Set the required start frequency.
NB!
NB!
NB!
NB!
NB!
If the FC motor is running at the current limit
before the desired start frequency is obtained,
the process regulator will not be activated. For the
regulator to be activated anyway, the start frequency
must be lowered to the required output frequency.
This can be done during operation.
440 Process PID proportional gain
(PROC. PROP. GAIN)
Settings:
0.00 (OFF) - 10.00
[0 - 1000]
✭
0.01
[1]
Function:
The proportional gain indicates the number of times
the error between the set point and the feedback
signal is to be applied.
Used together with
Process, closed loop mode
(parameter 100).
Description of choice:
Quick regulation is obtained by a high gain, but if the
gain is too high, the process may become unstable.
441 Process PID integral time
(PROC. INTEGR. T.)
Settings:
0.01 - 9999 sec. (OFF)
[1 - 999900]
✭
9999 sec.
[999900]
Function:
The integrator provides an increasing gain at a
constant error between the set point and the
feedback signal. The greater the error, the quicker the
gain will increase. The integral time is the time needed
by the integrator to reach the same gain as the
proportional gain.
Used together with
Process, closed loop
mode
(parameter 100).
Description of choice:
Quick regulation is obtained at a short integral time.
However, this time may become too short, which can
make the process unstable.
If the integral time is long, major deviations from the
required set point may occur, since the process
regulator will take a long time to regulate in relation to
a given error.
442 Process PID differentiation time
(PROC. DIFF. TIME)
Settings:
0.00 (OFF) - 10.00 sec.
[0 - 1000]
✭
0.00 sec.
[0]
Function:
The differentiator does not react to a constant error. It
only provides a gain when the error changes. The
quicker the error changes, the stronger the gain from
the differentiator.
The gain is proportional to the speed at which the
error changes.
Used together with
Process, closed loop mode
(parameter 100).
Description of choice:
Fast regulation is obtained with a long differentiation
time. However, this time may become too long, which
can make the process unstable.
443 Process PID diff. gain limit
(PROC. DIFF. GAIN)
Settings:
5.0 - 50.0
[50 - 500]
✭
5.0
[50]
Function:
It is possible to set a limit for the differentiator gain.
The differentiator gain will increase if there are fast
changes, which is why it can be beneficial to limit this
gain, thereby obtaining a pure differentiator gain at
slow changes and a constant differentiator gain where
quick changes to the error occur.
Used together with
Process, closed loop mode
(parameter 100).
