Hitachi RAM-90QH5, Service Manual, Page: 74 / 83

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TROUBLE SHOOTING
Model RAM-90QH5
PRECAUTIONS FOR CHECKING
1. Remember that the
0V line is biased to
162V in reference to
the ground level.
2. Also note that it takes
about 10 minutes
until the voltage fall
after the power switch
is turned off.
Across a – b (0V line)....................
Across a – ground..........................
Across b (0V line)– ground............
approx 360V
approx 155-170V
approx 155-170V
When using an
oscilloscope, never
ground it. Don't forget
that high voltages as
noted above may
apply to the
oscilloscope.
DANGER
DANGER
+
–
+
– +
– +
– +
– +
– +
–
Power source
1 ø220-240V, 50/60Hz
N L
A
CT Module
IPM
Smoothing Capacitor
Compressor motor
Main P. W. B
C DC 35V
0V
Control
P. W. B
D
a
b (0V)
M