When a motor is controlled by a frequency converter,
resonance noise will be heard from the motor. This
noise, which is caused by the design of the motor, oc-
curs each time one of the inverter switches in the
frequency converter is activated. Consequently, the
resonance noise frequency corresponds to the switch-
ing frequency of the frequency converter.
For the VLT 6000 HVAC, Danfoss offers a LC filter to
dampen the acoustic motor noise.
This filter reduces the voltage rise time, the peak volt-
age U
PEAK
and the ripple current
∆
I to the motor,
thereby making current and voltage almost sinusoidal.
The acoustic motor noise is therefore reduced to a
minimum.
Because of the ripple current in the coils, there will be
some noise from the coils. This problem can be solved
entirely by integrating the filter in a cabinet or similar.
Examples of the use of LC filters
Submersible pumps
For small motors with up to and including 5.5 kW rated
motor power, use an LC filter, unless the motor is
equipped with phase separation paper. This applies
e.g. to all wet running motors. If these motors are used
without LC filter in connection with a frequency con-
verter, the motor windings will short-circuit. If in doubt,
ask the motor manufacturer whether the motor in
question is equipped with phase separation paper.
Well pumps
If immersion pumps are used, e.g. submerged pumps
or well pumps, the supplier should be contacted for
clarification of requirements. It is recommended to use
a LC filter if a frequency converter is used for well
pump applications.
VLT
®
6000 HVAC Series
36
MG.61.B5.02 - VLT
®
is a registered Danfoss trademark
Содержание VLT 6000 HVAC Series
Страница 31: ...Ordering form VLT 6000 HVAC Series MG 61 B5 02 VLT is a registered Danfoss trademark 31 Introduction to HVAC ...
Страница 63: ...Mechanical dimensions VLT 6000 HVAC Series MG 61 B5 02 VLT is a registered Danfoss trademark 63 Installation ...
Страница 75: ...VLT 6000 HVAC Series MG 61 B5 02 VLT is a registered Danfoss trademark 75 Installation ...
Страница 204: ...VLT 6000 HVAC Series 204 MG 61 B5 02 VLT is a registered Danfoss trademark ...