Hitachi RAD25QH4, Service Manual

Page: 191 / 293

Ð 210 Ð
● ●
Fig.
3-1
shows
the
power
module
and
its
peripheral
circuit.
The
three
transistors
on
the
positive
+
side
are
called
the
upper
arm,
and
the
three
transistors
on
the
negative
-
side,
the
lower
arm.
3. Power Module Circuit
W
coil
V
◯
A
DC compressor motor
U
U
coil
V
coil
W
◯−
R24
+ -
+ -
+ -
System
Power
Module2
Fig.
3-1
Power
module
circuit
(U
+
is
ON,
V
-
is
ON)
W
-
V
-
U
-
W
+
V
+
U+
FUSE(25A)
0.35mH
◯＋
Noise
filter
coil
1
Terminal board
L
N
C009(C012)
C503
C501
C502
R002(R003) Inrush
prevention
relay
R001
Power
relay
Reactor
B
RAM-70QH4
and
RAM-80QH4
have
two
power
module
circuits
as
shown
in
Fig.
3-1
because
of
providing
for
two
cycles
and
two
compressors
style.