Outdoor Unit Failure Mode Table - Mitsubishi Electric Mr.Slim MUZ-GE09NA Service Manual

3. Outdoor unit failure mode table

OPERATION
INDICATOR Abnormal point
upper lamp (Failure mode / protection)
(Indoor unit)
OFF None (Normal)
2-time fl ash Outdoor power system
2.5 seconds
OFF
3-time fl ash Discharge temperature
2.5 seconds thermistor
OFF
Defrost thermistor (MUZ)
Fin temperature thermistor
P.C. board temperature
thermistor
Ambient temperature
thermistor
Outdoor heat exchanger
temperature thermistor
(MUZ/MUY-GE24NA)
4-time fl ash Overcurrent
2.5 seconds
OFF
Compressor synchronous
abnormality (Compressor start-
up failure protection)
5-time fl ash Discharge temperature
2.5 seconds
OFF
6-time fl ash High pressure
2.5 seconds
OFF
7-time fl ash Fin temperature/ P.C. board
2.5 seconds temperature
OFF
8-time fl ash Outdoor fan motor
2.5 seconds
OFF
9-time fl ash Nonvolatile memory data
2.5 seconds
OFF
Power module
(MUZ/MUY-GE24NA)
10-time fl ash Discharge temperature
2.5 seconds
OFF
11-time fl ash DC voltage
2.5 seconds
OFF
Each phase current of
compressor
12-time fl ash Overcurrent Compressor open-
2.5 seconds phase
OFF
14-time fl ash Stop valve (Closed valve)
2.5 seconds
OFF
NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).
LED indication
(Outdoor P.C. board)
—
Overcurrent protection stop is
continuously performed 3 times within
— 1 minute after the compressor gets
started.
1-time fl ash every Thermistor shorts or opens during
2.5 seconds compressor running.
3-time fl ash
2.5 seconds OFF
4-time fl ash
2.5 seconds OFF
2-time fl ash
2.5 seconds OFF
11-time fl ash Large current fl ows into intelligent
2.5 seconds OFF power module.
12-time fl ash Waveform of compressor current is
2.5 seconds OFF distorted.
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.
Temperature of indoor coil thermistor
exceeds 158°F (70°C) in HEAT mode
(MUZ only). Temperature of outdoor
—
heat exchanger temperature thermistor
exceeds 158°F (70°C) in COOL mode.
7-time fl ash Temperature of fi n temperature
2.5 seconds OFF thermistor on the inverter P.C. board
exceeds 167 ~ 176°F (75 ~ 80°C), or
temperature of P.C. board temperature
thermistor on the inverter P.C. board
exceeds 158 ~ 167°F (70 ~ 75°C).
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor fan
—
start-up.
5-time fl ash Nonvolatile memory data cannot be
2.5 seconds OFF read properly.
6-time fl ash The interphase short circuit occurs
2.5 seconds OFF in the output of the intelligent power
module (IPM). The compressor winding
shorts circuit.
Temperature of discharge temperature
thermistor has been 122°F (50°C) or
—
less for 20 minutes.
8-time fl ash DC voltage of inverter cannot be
2.5 seconds OFF detected normally.
9-time fl ash Each phase current of compressor
2.5 seconds OFF cannot be detected normally.
10-time fl ash Large current fl ows into intelligent
2.5 seconds OFF power module (IPM).
The open-phase operation of
compressor is detected.
The interphase short circuit occurs
in the output of the intelligent power
module (IPM).
The compressor winding shorts circuit.
14-time fl ash Closed valve is detected by compressor
2.5 seconds OFF current.
Condition
—
• Reconnect connectors.
• Refer to 10-5.
to check inverter/
compressor".
• Check stop valve.
• Refer to 10-5. "Check
of outdoor thermistors".
Defective outdoor
thermistors can be
identifi ed by checking
the blinking pattern of
LED.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check stop valve.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check refrigerant circuit
and refrigerant amount.
• Refer to 10-5. "Check
of LEV".
• Check refrigerant circuit
and refrigerant amount.
• Check 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".
Refer to 10-5. "Check
of inverter P.C. board".
• Replace the inverter
P.C. board.
• Refer to 10-5. "How
to check inverter/
compressor".
• Refer to 10-5. "Check
of LEV".
• Check refrigerant circuit
and refrigerant amount.
• Refer to 10-5. "How
to check inverter/
compressor".
• Reconnect compressor
connector.
• Refer to 10-5.
to check inverter/
compressor".
• Check stop valve
34
Indoor/
Outdoor unit
outdoor unit
Remedy failure mode
failure mode
recall function
recall function
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