Sine-Wave Filters - Danfoss VLT AutomationDrive FC 300 Design Manual

FC 300 Design Guide
IP 21/Type 1 Enclosure Kit
A – Top cover
B – Brim
C – Base part
D – Base cover
E – Screw(s)
Place the top cover as shown. If an A or B option
is used the brim must be fitted to cover the top
inlet. Place the base part C at the bottom of the
drive and use the clamps from the accessory bag
to correctly fasten the cables. Holes for cable
glands:
Size A2: 2x M25 and 3xM32
Size A3: 3xM25 and 3xM32

Sine-wave Filters

When a motor is controlled by a frequency converter, resonance noise will be heard from the motor. This
noise, which is the result of the design of the motor, arises every time an inverter switch in the frequency
converter is activated. The frequency of the resonance noise thus corresponds to the switching frequency
of the frequency converter.
For the FC 300 Series, Danfoss can supply a Sine-wave filter to dampen the acoustic motor noise.
The filter reduces the ramp-up time of the voltage, the peak load voltage U
∆I to the motor, which means that current and voltage become almost sinusoidal. Consequently, the
acoustic motor noise is reduced to a minimum.
The ripple current in the Sine-wave Filter coils, will also cause some noise. Solve the problem by inte-
grating the filter in a cabinet or similar.
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Options and Accessories
MG.33.B8.02 - VLT ® is a registered Danfoss trademark
and the ripple current
PEAK