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VLT
®
FCM Series
Programming
Description of choice:
Set the required frequency.
411 Switching frequency
(SWITCH FREQ.)
Value:
1.5 -14.0 kHz
[1500 - 14000]
✭
Unit dependent
Function:
The setting determines the switching frequency of the
inverter. If the switching frequency is changed, this may
help to minimise possible acoustic noise from the motor.
Description of choice:
When the motor is running, the switching frequency is
adjusted in parameter 411 until the frequency has been
obtained at which the motor is as low-noise as possible.
See also parameter 446 - switching pattern.
See derating in chapter 10.
NB!:
Switching frequencies higher than 4 kHz
may cause thermal trip depending on
ambient temperature.
412 Variable switching frequency
(VAR CARRIER FREQ)
Value:
Not possible (DISABLE)
[0]
Variable switching freq. (VAR. CARRIER FREQ.)
[1]
✭
Temperature dep. sw. freq. (TEMP. DEP. FREQ.)
[2]
Function:
This function makes it possible to change the
switching frequency depending on the load. However,
the maximum switching frequency is determined
by the value set in parameter 411.
Description of choice:
Select
Not possible
[0] if a permanent switching
frequency is desired. Set the switching
frequency in parameter 411.
If
Variable switching frequency
[1] is selected the
switching frequency will decline at an increasing
output frequency. This is used in applications
with square torque characteristics (centrifugal
pumps and fans) in which the load declines
depending on the output frequency.
If
Temperature dependent switching frequency
[2] is
selected, the switching frequency will decline at an
increasing inverter temperature, see the drawing below.
413 Overmodulation function
(OVERMODULATION)
Value:
Off (OFF)
[0]
✭
On (ON)
[1]
Function:
This parameter allows connection of the
overmodulation function for the output voltage.
Description of choice:
Off
means that there is no overmodulation of the
output voltage, which means that torque ripple on
the motor shaft is avoided. This can be a good
feature, e.g. on grinding machines.
On
means that an output voltage can be obtained
which is greater than the mains voltage (up to 5%).
414 Minimum feedback
(MIN. FEEDBACK)
Value:
-100,000,000 - FB
HIGH
(PAR. 415)
[-100000000 -]
✭
0.000
[0]
Function:
Parameters 414 and 415 are used to scale the
feedback range to physical values used by the
user. The setting will also be the bounds of the
reference (parameters 204 and 205).
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.03.H3.02 - VLT is a registered Danfoss trademark
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