Outdoor Unit Failure Mode Table - Mitsubishi Electric 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-GE24, MUY-GE24)
4-time fl ash Overcurrent
2.5 seconds
OFF
Compressor synchronous
abnormality (Compressor start-
up failure protection)
Discharge temperature
5-time fl ash
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-GE24, MUY-GE24)
Discharge temperature
10-time fl ash
2.5 seconds
OFF
NOTE: Blinking patterns of this mode differ from the ones of Troubleshooting check table (10-3.).
1
Intelligent power module: MUZ-GE09/12/15/18/24NA, MUY-GE09/12/15/18/24NA
Power module: Other models
OBH549F
LED indication
(Outdoor P.C. board)
—
Overcurrent protection cut-out operates
3 consecutive 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/ power module 1.
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)/power module (IPM) 1.
The compressor winding shorts circuit.
Temperature of discharge temperature
thermistor has been 122°F (50°C) or
less for 20 minutes.
—
47
Condition Remedy
—
• 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.
Indoor/
Outdoor unit
outdoor unit
failure mode
failure mode
recall function
recall function
— —
"How
○
○
—
—
—
—
—
—
○
—
—
○
○
○
○
○
○
○
○
○
○