Communication Options; Input/Output, Feedback, And Safety Options; Sine-Wave Filters; Du/Dt Filters - Danfoss VLT Refrigeration Drive FC 103 Design Manual

System Integration
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Keeps fieldbusses active during power cuts.
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Ordering numbers:
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3 3

3.8.1 Communication Options

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®
VLT
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VLT
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®
VLT
For further information, refer to chapter 7 Specifications.
3.8.2 Input/Output, Feedback, and Safety
Options
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®
VLT
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®
VLT
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®
VLT
For further information, refer to chapter 7 Specifications.

3.8.3 Sine-wave Filters

When a frequency converter controls a motor, resonance
noise is heard from the motor. This noise, which is the
result of the motor design, occurs 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.
Danfoss supplies 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
motor, which means that current and voltage become
almost sinusoidal. So, the acoustic motor noise is reduced
to a minimum.
The ripple current in the sine-wave filter coils also causes
some noise. Solve the problem by integrating the filter in a
cabinet or similar.
66
130B1108 uncoated.
130B1208 coated (Class G3/ISA
S71.04-1985).
PROFIBUS DP-V1 MCA 101
AK-LonWorks MCA 107
PROFINET MCA 120
General Purpose I/O Module MCB 101
Relay Card MCB 105
Extended Relay Card MCB 113
, and the ripple current ΔI to the
PEAK
Danfoss A/S © 08/2015 All rights reserved.
®
VLT Refrigeration Drive FC 103

3.8.4 dU/dt Filters

Danfoss supplies dU/dt filters which are differential-mode,
low-pass filters that reduce motor terminal phase-to-phase
peak voltages and reduce the rise time to a level that
lowers the stress on the insulation at the motor windings.
This is especially an issue with short motor cables.
Compared to sine-wave filters (see chapter 3.8.3 Sine-wave
Filters), the dU/dt filters have a cut-off frequency above the
switching frequency.

3.8.5 Harmonic Filters

®
The VLT
are advanced harmonic filters, not to be compared with
traditional harmonic trap filters. The Danfoss harmonic
filters have been specially designed to match the Danfoss
frequency converters.
Connecting the Danfoss harmonic filters AHF 005 or AHF
010 in front of a Danfoss frequency converter reduces the
total harmonic current distortion generated back to the
mains to 5% and 10%.
Advanced Harmonic Filter AHF 005 and AHF 010
MG16G202