3.14 Main Menu - Special Functions -Group 14
3.14.1 14-0* Inverter Switching
14-00 Switching Pattern
Option:
Function:
Select the switching pattern: 60° AVM or SFAVM.
[0]
*
60 AVM
[1]
SFAVM
14-01 Switching Frequency
Option:
Function:
Select the inverter switching frequency. Changing
the switching frequency can help to reduce
acoustic noise from the motor.
NOTE
The output frequency value of the
frequency converter must never exceed 1/10
of the switching frequency. When the motor
is running, adjust the switching frequency in
until the motor is
as noiseless as possible. See also
and the section
Derating
.
[0]
1.0 kHz
[1]
1.5 kHz
[2]
2.0 kHz
[3]
2.5 kHz
[4]
3.0 kHz
[5]
3.5 kHz
[6]
4.0 kHz
[7]
*
5.0 kHz
[8]
6.0 kHz
[9]
7.0 kHz
[10] 8.0 kHz
[11] 10.0 kHz
[12] 12.0 kHz
[13] 14.0 kHz
[14] 16.0 kHz
NOTE
Enabling over-modulation can cause vibrations that may
destroy the mechanics if running in field weakening ares
(from 47Hz).
14-03 Overmodulation
Option: Function:
[0]
Off Selects no over-modulation of the output voltage in
order to avoid torque ripple on the motor shaft.
[1]
*
On The over-modulation function generates an extra
voltage of up-to 8% of U
max
output voltage without
over-modulation, which results in an extra torque of
10-12% in the middle of the over-syncronous range
14-03 Overmodulation
Option: Function:
(from 0% at nominal speed rising to approximately
12% at double nominal speed).
14-04 PWM Random
Option: Function:
[0]
*
Off No change of the acoustic motor switching noise.
[1]
On Transforms the acoustic motor switching noise from a
clear ringing tone to a less noticeable ‘white’ noise.
This is achieved by slightly and randomly altering the
synchronism of the pulse width modulated output
phases.
3.14.2 14-1* Mains On/Off
Parameters for configuring mains failure monitoring and
handling.
14-10 Mains Failure
Option:
Function:
Select the function at which the frequency
converter must act, when the threshold set in
14-11 Mains Voltage at Mains Fault
has been
reached or a
Mains Failure Inverse
command is
activated via one of the digital inputs (par.
5-1*).
Only selection [0] No function, [3] Coasting or
[6] Alarm is available when
is set to [1] PM non salient SPM
[0]
*
No
function
The energy left in the capacitor bank will be
used to "drive" the motor, but will be
discharged.
[1]
Ctrl. ramp-
down
The frequency converter will perform a
controlled ramp down.
must be set to
Off
[0].
[3]
Coasting
The inverter will turn off and the capacitor
bank will back up the control card then
ensuring a faster restart when mains
reconnected (at short power zags).
[4]
Kinetic
back-up
The frequency converter will ride through by
controlling speed for generative operation of
the motor utilizing the moment of inertia of
the system as long as sufficient energy is
present.
[6]
Alarm
Parameter Description
VLT
®
HVAC Drive Programming Guide
108
MG.11.CC.02 - VLT
®
is a registered Danfoss trademark
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