Service manual

x
3
DC /AC
o
C
Temp
.
conv.
uC+
EEP
7 xGD
RL 1
GD
Supply
A
BR
GD
BR
FB
INV
GD
AC / DC
Thyristor x3
BR
P _BRF
RL 2
Inrush
SAFE
_
FB
Tmp
_
VGDS
VCC
FAN
CAN
A
A
Imax 2 comp.
RL
2
RL
1
Tmp_VGDS
Inrush
RFI
_
RL 2
RFI
_
RL 1
FFB
Int
.
fans
”Internal supply bus”
”Internal Communication”
Level
Shift
VCX (GX) 5V
VCC (GND) 5V
VDD (GND) 24V
SMPS
Motor
U
V
W
UINV
_
P
UINV
_
N
RFI
_
RL 2
RFI _RL 1
MAINS
RFI (variations
)
L 1
L 2
L 3
VDD (GND ) 24V
Pulse
E _FAN
E _FFB
Ext.
fans
Control Card
ACP
Isol. RS 485
D-I/O
A-I/O
MCP
LCP
Display
control
panel
Brake not connected to terminal on FC 101
130BC135.10
Illustration 3.4 Example of H7, H8, I7, I8 Power and Control Section
3.3.2
Intermediate Section
Following the rectifier section, voltage passes to the
intermediate section. An LC filter circuit consisting of the
DC bus inductor and the DC bus capacitor bank smooths
the rectified voltage.
The DC bus inductor provides series impedance to
changing current. This impedance aids the filtering process
while reducing harmonic distortion to the input AC current
waveform normally inherent in rectifier circuits.
The DC capacitor bank assembly consists of up to six
capacitors arranged in series/parallel configuration. A
bleeder circuit maintains equal voltage drops across each
capacitor. It also provides a current path for discharging
the capacitors once power has been removed from the
frequency converter.
Also located in the intermediate section is the High
Frequency (HF) filter film capacitors. These capacitors
reduce the common mode noise caused by switching into
stray capacitors to earth in cable and motor.
In some units, RFI relay 2 can be opened to minimize
voltage charge up.
If DC-link increases above a certain level specified in EE-
prom for each unit, RFI relay 2 opens automatically.
Internal Frequency Converte...
VLT
®
HVAC Basic Drive Service Manual
26 MG90X202 - VLT
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is a registered Danfoss trademark
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