25
3. Outdoor unit failure recall 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 Remedy
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.).
OBH502E
