Hitachi RAM-55QH4, Service Manual

Page: 72 / 109

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3. System power Module Circuit
Fig.
3-1
sho
ws t
he system
po
w
er module and its per
ip
her
al
circuits
. (Current A
CT module and po
w
er module are
combin
ed into one unit.)
Th
e thr
ee tr
a
nsistors on the p
ositiv
e side are called the upper ar
m,
and the three tr
ansistors on
the neg
ativ
e
side
, the lo
w
er ar
m.
A
U
U
-
V
-
W
-
V
W
W
V U
U coil
V coil
W coil
DC compressor motor
System P
o
w
er Module
FUSE(25A)
T
e
rminal
board
N
L
R004
C006
Noise filter coil
R002
R24
Coil
lnr
ush c
u
rrent
protec
tion
rela
y
P
o
w
er rela
y
0.35mH
A
CT MODULE
INVER
TER
Fig.
3-1 System po
w
er module circuit (U
+
is ON,
V
-
is ON)
•