Mitsubishi Electric Mr.Slim MUZ-A09NA Service Manual page 42

MUZ-A24NA MUY-A24NA MUZ-GA24NA MUY-GA24NA
The left lamp of
Abnormal point
OPERATION INDICATOR
(Failure mode / protection)
lamp (Indoor unit)
OFF None (Normal)
2-time fl ash Outdoor power system
3-time fl ash Discharge temperature
thermistor
Defrost thermistor (MUZ)
Ambient temperature
thermistor
Fin temperature thermistor
P.C. board temperature
thermistor
Outdoor heat exchanger
temperature thermistor
4-time fl ash Overcurrent
5-time fl ash Discharge temperature
6-time fl ash High pressure
7-time fl ash Fin temperature
P.C. board temperature
8-time fl ash Outdoor fan motor
9-time fl ash Nonvolatile memory data
10-time fl ash Discharge temperature
11-time fl ash Communication error between
P.C. boards
Current sensor
Zero cross detecting circuit
Converter
Bus-bar voltage
(1)
Bus-bar voltage
(2)
Even if this protection stop
is performed continuously
3 times, it does not mean
the abnormality in outdoor
power system.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.).
LED indication
(Outdoor P.C. board)
LED1 LED2
Lighting Lighting
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.
Lighting Once Thermistor shorts or opens during compressor
running.
Lighting Once
Lighting Twice
Lighting 3 times
Lighting 4 times
Lighting 9 times
Once Goes out 28 A current fl ows into intelligent power module. • Reconnect compressor
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.
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.
3 times Goes out The fi n temperature exceeds 189°F (87°C)
during operation.
4 times Goes out The P.C. board temperature exceeds 158°F (70°
C) during operation.
Lighting Lighting Failure occurs continuously three times within
30 seconds after the fan gets started.
Lighting 5 times Nonvolatile memory data cannot be read
properly.
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.
Lighting 6 times Communication error occurs between the
electronic control P.C. board and power board
for more than 10 seconds.
The communication between boards protection
stop is continuously performed twice.
Lighting 7 times A short or open circuit is detected in the current
sensor during compressor operating.
Current sensor protection stop is continuously
performed twice.
5 times Goes out Zero cross signal cannot be detected while the
compressor is operating.
The protection stop of the zero cross detecting
circuit is continuously performed 10 times.
5 times Goes out A failure is detected in the operation of the
converter during operation.
5 times Goes out The bus-bar voltage exceeds 400 V or falls to
200 V or below during compressor operating.
6 times Goes out The bus-bar voltage exceeds 400 V or falls to 50
V or below during compressor operating.
Condition
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42
Indoor/outdoor
unit failure
Correspondence
mode recall
—
• Check the connection of the
compressor connecting wire.
• Refer to 10-5. "How to
check inverter/compressor".
• Check the stop valve.
• Refer to 10-5. "Check of
outdoor thermistors".
• Replace the outdoor
electronic control P.C. board.
• Refer to 10-5. "Check of
outdoor thermistors".
connector.
• Refer to 10-5. "How to
check inverter/compressor.
• Check the stop valve.
• Check refrigerant circuit and
refrigerant amount.
• Refer to 10-5. "Check of
LEV".
• Check refrigerant circuit and
refrigerant amount.
• Check the stop valve.
• Check around outdoor unit.
• Check outdoor unit air
passage.
• Refer to 10-5. "Check of
outdoor fan motor".
• Refer to 10-5. "Check of
outdoor fan motor".
• Replace the outdoor
electronic control P.C. board.
• Check refrigerant circuit and
refrigerant amount.
• Refer to 10-5. "Check of
LEV".
• Check the connecting wire
between outdoor electronic
control P.C. board and
power board.
• Replace the power board.
• Check the connecting wire
among electronic control
P.C. board, noise fi lter P.C.
board and power board.
• Check the voltage of power
supply.
• Replace the power board.
• Check the voltage of power
supply.
• Replace the outdoor
electronic control P.C. board.
function
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