Trouble Shooting - Hitachi RAS-70YH5 Service Manual

TROUBLE SHOOTING

DANGER
1. Remember that the
0V line is biased to
155-170V 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.
DANGER
When using an
oscilloscope, never
ground it. Don't forget
that high voltages as
noted above may
apply to the
oscilloscope.
0305E Pg 83-89
PRECAUTIONS FOR CHECKING
Power source
240
L N
+
~
Indoor unit
electric parts
C
Control
D
P.W.B.
Outdoor unit P.W.B.
86
System power module 2
a
~
+ + +
— — —
b (0V)
DC35V
MAIN P.W.B.
0V
Across a – b (0V line)....................
Across a – ground..........................
Across b (0V line)– ground............
Always keep your hands
and metallic things away
from the enclosure of the
oscilloscope.
Oscilloscope
– 86 –
4/1/06, 11:00 AM
M
Compressor motor
approx 260-360V
approx 155-170V
approx 155-170V
DANGER!
Don't install
the ground
line.