Mitsubishi Electric Mr.Slim MUZ-A09NA Service Manual page 41

3. Outdoor unit failure mode table
MUZ-A09/12/15/17NA MUY-A15/17NA
The left lamp of
Abnormal point
OPERATION INDICATOR
(Failure mode / protection)
lamp (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 OFF thermistor
Defrost thermistor (MSZ)
Fin temperature thermistor
P.C. board temperature
thermistor
Ambient temperature
thermistor
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 OFF temperature
8-time fl ash Outdoor fan motor
2.5 seconds OFF
9-time fl ash Nonvolatile memory data
2.5 seconds OFF
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
2.5 seconds OFF Compressor open-phase
14-time fl ash Outdoor unit
2.5 seconds OFF (Other abnormality)
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 24 A (09/12) / 26.5 A (15/17) current
2.5 seconds OFF fl ows into intelligent 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.
Indoor coil thermistor temperature
exceeds 158°F (70°C) in HEAT mode.
— (MUZ)
Defrost 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 180°F (82°C) (09/12) /188°
F (86.5°C) (15/17), or temperature of
P.C. board temperature thermistor on
the inverter P.C. board exceeds 176°F
(80°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.
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 24 A (09/12) / 26.5 A (15/17) current
2.5 seconds OFF fl ows into intelligent power module
(IPM).
The open-phase operation of
compressor is detected.
The interphase short out occurs in the
output of the intelligent power module
(IPM).
The compressor winding shorts out.
The inverter P.C. board is defective.
—
Condition Correspondence
—
• 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.
to check inverter/
compressor".
• Check stop valve.
• Reconnect
compressor
connector.
• Refer to 10-5.
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.
"Check of LEV".
• Check refrigerant
circuit and refrigerant
amount.
• Refer to 10-5.
to check inverter/
compressor".
• Reconnect
compressor
connector.
• Refer to 10-5.
to check inverter/
compressor"
• Replace the inverter
P.C. board.
41
Indoor/outdoor
Outdoor unit
unit failure
failure mode
mode recall
recall function
function
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