Outdoor Unit Failure Mode Table - Mitsubishi Electric MUZ-FH09NA Service Manual

3. Outdoor unit failure mode table

The left
lamp of the
OPERATION Abnormal point
INDICATOR (Failure mode/protection)
lamp
(Indoor unit)
OFF None (Normal)
1-time fl ash Indoor/outdoor
2.5 seconds communication, receiving
OFF error
Indoor/outdoor
communication, receiving
error
2-time fl ash Outdoor power system
2.5 seconds
OFF
3-time fl ash Discharge temperature
2.5 seconds thermistor
OFF
Defrost thermistor
Fin temperature thermistor
P.C. board temperature
thermistor
Ambient temperature
thermistor
Outdoor heat exchanger
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 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 (IC700)
(FH09/12)
IGBT module (IC700) (FH15)
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.).
OBH584A
LED indication
(Outdoor P.C. board)
—
Any signals from the inverter P.C.
— board cannot be received normally for
3 minutes.
Although the inverter P.C. board
— sends signal "0", signal "1" has been
received 30 consecutive times.
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 the power
2.5 seconds OFF module (IC700) (FH09/12)/ IGBT
module (IC700) (FH15).
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 indoor coil thermistor
exceeds 158°F (70°C) in HEAT
—
mode. Temperature defrost thermistor
exceeds 158°F (70°C) in COOL mode.
7-time fl ash Temperature of the fi n temperature
2.5 seconds OFF thermistor on the inverter P.C. board
exceeds 167 ~ 187°F (75 ~ 86°C)
(FH09/12)/167 ~ 176°F (75 ~ 80°C)
(FH15), or temperature of P.C. board
temperature thermistor on the inverter
P.C. board exceeds 162 ~ 185°F (72 ~
85°C) (FH09/12)/158 ~ 167°F (70 ~ 75
°C) (FH15).
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 interface short circuit occurs in the
2.5 seconds OFF output of the power module (IC700)
(FH09/12)/IGBT module (IC700)
(FH15).
The compressor winding shorts circuit.
26
Condition Remedy
—
•Refer to 10-5.
to check miswiring and
serial signal error.
•Refer to 10-5.
to check miswiring and
serial signal error.
• 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.
to check inverter/
compressor".
Indoor/outdoor
Outdoor unit
unit failure
failure mode
mode recall
recall function
function
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