25
3. Outdoor unit failure mode table
MUZ-D30NA MUZ-D36NA MUY-D30NA MUY-D36NA
The left lamp of OPERA-
TION INDICATOR lamp
(Indoor unit)
Abnormal point
(Failure mode / protection)
LED indication
(Outdoor P.C.
board)
Condition Correspondence
Indoor/outdoor
unit failure mode
recall function
LED 1
LED 2
OFF Non
(Normal)
Lighting
Lighting
—
—
—
2-time
fl
ash
Outdoor power system
Lighting Lighting
IPM protection stop or lock protection stop is continuously
performed 3 times within 1 minute after the compres-
sor gets started, or converter protection stop or bus-bar
voltage protection stop is continuously performed 3 times
within 3 minutes after start-up.
Check the connection of the
compressor connecting wire.
Refer to 10-5. "How to check
inverter/compressor".
Refer to 10-5. "Check of
compressor start failure".
Check the stop valve.
•
•
•
•
○
3-time
fl
ash
Discharge temperature thermistor Lighting
Once
Thermistor shorts or opens during compressor running.
Refer to 10-5. "Check of
outdoor thermistors".
•
○
Defrost thermistor (MUZ)
Lighting
Once
Ambient temperature thermistor
Lighting
Twice
Fin temperature thermistor
Lighting 3 times
P.C. board temperature thermistor Lighting 4 times
Replace the outdoor electronic
control P.C. board.
•
Outdoor heat exchanger tempera-
ture thermistor
Lighting 9
times
Refer to 10-5. "Check of
outdoor thermistors".
•
4-time
fl
ash
Overcurrent
Once
Goes
out
28 A current
fl
ow into intelligent power module.
Reconnect compressor con-
nector.
Refer to 10-5. "How to check
inverter/compressor."
Refer to 10-5. "Check of
compressor start failure".
Check the stop valve.
•
•
•
•
—
5-time
fl
ash
Discharge temperature
Lighting Lighting
Temperature of discharge temperature thermistor exceeds
241°F (116°C), compressor stops. Compressor can restart
if discharge temperature thermistor reads 212°F (100°C)
or less 3 minutes later.
Check refrigerant circuit and
refrigerant amount.
Refer to 10-5. "Check of
LEV".
•
•
—
6-time
fl
ash
High pressure
Lighting Lighting
The outdoor heat exchanger temperature exceeds 158°F
(70°C) during cooling or the indoor gas pipe temperature
exceeds 158°F (70°C) during heating (MUZ).
Check refrigerant circuit and
refrigerant amount.
Check the stop valve.
•
•
—
7-time
fl
ash
Fin temperature
3 times
Goes
out
The
fi
n temperature exceeds 189°F (87°C) during opera-
tion.
Check around outdoor unit.
Check outdoor unit air pas-
sage.
Refer to 10-5. "Check of
outdoor fan motor".
•
•
•
—
P.C. board temperature
4 times
Goes
out
The P.C. board temperature exceeds 158°F (70°C) during
operation.
8-time
fl
ash
Outdoor fan motor
Lighting Lighting Failure occurs continuously 3 times within 30 seconds
after the fan gets started.
Refer to 10-5. "Check of
outdoor fan motor".
•
—
9-time
fl
ash
Nonvolatile memory data
Lighting 5 times Nonvolatile memory data cannot be read properly.
Replace the outdoor electronic
control P.C. board.
•
○
10-time
fl
ash
Discharge temperature
Lighting Lighting
The frequency of the compressor is kept 80 Hz or more
and the discharge temperature is kept under 102°F (39°C)
for more than 20 minutes.
Check refrigerant circuit and
refrigerant amount.
Refer to 10-5. "Check of
LEV".
•
•
—
11-time
fl
ash
Communication error between
P.C. boards
Lighting 6
times
Communication error occurs between the electronic control
P.C. board and power board for more than 10 seconds.
Check the connecting wire
between outdoor electronic
control P.C. board and power
board.
•
—
The communication between boards protection stop is
continuously performed twice.
○
Current sensor
Lighting 7 times
A short or open circuit is detected in the current sensor
during compressor operating.
Replace the power board.
•
—
Current sensor protection stop is continuously performed
twice.
○
Zero cross detecting circuit
5 times Goes out
Zero cross signal cannot be detected while the compres-
sor is operating.
Check the connecting wire
among electronic control P.C.
board, noise
fi
lter P.C. board
and power board.
•
—
The protection stop of the zero cross detecting circuit is
continuously performed 10 times.
○
NOTE
: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).
