Mitsubishi Electric MUZ-GC25VA, Service Manual

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32
Check of outdoor fan motor
I
Outdoor fan motor does not operate.
Replace the
outdoor fan motor.
Does upper lamp of
OPERATION INDICATOR
lamp on the indoor unit
light up?
Is the resistance of fan
motor normal?
3 minutes after, is there
voltage 230V AC
between CN771
2
and
3
on the inverter P.C.
board?
Disconnect the connector CN771 on inverter P.C.
board.
Disconnect the connector (CN61) between
compressor and power transistor module.
Turn ON the power supply and press the
EMERGENCY OPERATION switch.
Yes
Yes
No
Check the resistance of fan motor. (Refer to 11-4.)
Replace the inverter
P.C. board.
No
Replace the outdoor
fan motor.
MUZ-GC25VA MUZ-GC25VAH
MUZ-GC35VA MUZ-GC35VAH
Does the voltage between
each terminal repeat 5V
and 0V DC by turns?
Does the outdoor fan
rotate smoothly?
Check the inverter P.C. board.
(Refer to 11-5.
M
)
No
Yes
Yes
( Fixed to either 5V or 0V DC)
Yes
No
No
Rotate the outdoor fan slowly
by hand, and measure the
voltage of CN931 (Measurement
of feedback output).
Between
1
(+) and
5
(-)
Between
2
(+) and
5
(-)
Between
3
(+) and
5
(-)
Is the resistance
between each terminal of
outdoor fan motor normal?
(Refer to 11-4.)
Disconnect CN932
from the inverter
P.C. board.
Replace the outdoor fan
motor.
CN931
CN932
Inverter P.C. board
(Solder side)
Turn ON the
power supply.
OBH469--2.qxp 07.1.22 1:30 PM Page 32