Hitachi RAC-25NH5, Service Manual, Page: 64 / 112

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3. Power Module Circuit
●
Fig. 3-1 shows the system power module and its peripheral circuit. The three transistors on the positive
e
side are called the upper arm, and the three transistors on the negative
d
side, the lower arm.
+
W
U V W
W
–
+
V
V
–
+
U
U
–
A
+
DC Compressor motor
U coil
V coil
W coil
System P
o
w
er module 2
+
–
C501
+
–
C502
+
–
C503
R24
0.35
m
H
P
o
w
er rela
y
Coil
R007
R008
Inr
ush current
protection rela
y
C006
R001
Noise filter coil
L N
T
e
rminal
board
FUSE (25A)
Fig. 3-1 Power module circuit (U
+
is ON, V
–
is ON)