Service manual

42
MUZ-A24NA MUY-A24NA MUZ-GA24NA MUY-GA24NA
The left lamp of
OPERATION INDICATOR
lamp (Indoor unit)
Abnormal point
(Failure mode / protection)
LED indication
(Outdoor P.C. board)
Condition Correspondence
Indoor/outdoor
unit failure
mode recall
function
LED1 LED2
OFF None (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 compressor 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".
• 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
temperature thermistor
Lighting 9 times • Refer to 10-5.
"Check of
outdoor thermistors".
4-time fl ash Overcurrent Once Goes out 28 A current fl ows into intelligent power module. • Reconnect compressor
connector.
• Refer to 10-5. "How to
check inverter/compressor.
• Check the stop valve.
—
5-time fl ash Discharge temperature Lighting Lighting Discharge temperature exceeds 241°F (116°
C) during operation. 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.
• 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 operation.
• Check around outdoor unit.
• Check outdoor unit air
passage.
• 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 three 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
compressor 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.
○
Converter 5 times Goes out A failure is detected in the operation of the
converter during operation.
• Check the voltage of power
supply.
• Replace the power board.
—
Bus-bar voltage
(1)
5 times Goes out The bus-bar voltage exceeds 400 V or falls to
200 V or below during compressor operating.
Bus-bar voltage
(2)
Even if this protection stop
is performed continuously
3 times, it does not mean
the abnormality in outdoor
power system.
6 times Goes out The bus-bar voltage exceeds 400 V or falls to 50
V or below during compressor operating.
• Check the voltage of power
supply.
• Replace the outdoor
electronic control P.C. board.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.).