Trouble Shooting - Hitachi RAS-50WX8 Service Manual

TROUBLE SHOOTING

MODEL RAC-50WX8, RAC-D18EX3
DANGER
1.
Remember that the
0V line is biased to
320 - 360V 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.
PRECAUTIONS FOR CHECKING
Power source
1 φ, 220 - 230V, 50Hz
N L
Indoor unit
electric parts
C
Control
D
P.W.B.
Across a ー b (0V line)..................approx 320 - 360V
Across a ーground ........................approx 155 - 170V
Across b (0V line)−ground ............approx 155 - 170V
Outdoor unit P.W.B.
– 164 –
System power module 2
b (0V)
DC35V
MAIN P.W.B.
0V
Always keep your hands
and metallic things away
from the enclosure of the
oscilloscope.
a
M
Compressor motor
DANGER!
Don't install
the ground
line.
Oscilloscope