Mitsubishi Electric MUZ-LN25VGHZ Service Manual page 33

3. Outdoor unit failure recall mode table
POWER lamp Abnormal point
(Indoor unit) (Failure mode/protection)
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
startup 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)
OBH768
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 power module
2.5 seconds OFF (IC700).
12-time fl ash Waveform of compressor current is
2.5 seconds OFF distorted.
Temperature of discharge temperature
thermistor exceeds 116°C, compressor
stops.
—
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
Temperature of indoor coil thermistor
exceeds 70°C in HEAT mode.
—
Temperature of defrost thermistor
exceeds 70°C in COOL mode.
7-time fl ash Temperature of fi n temperature thermistor
2.5 seconds OFF on the inverter P.C. board exceeds 75 ~
86°C (LN25/35) / 75 ~ 80°C (LN50), or
temperature of P.C. board temperature
thermistor on the inverter P.C. board
exceeds 72 ~ 85°C (LN25/35) / 70 ~ 75°C
(LN50).
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor
—
fan startup.
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).
The compressor winding shorts circuit.
NOTE: Blinking patterns of this mode differ from the ones of
TROUBLESHOOTING CHECK TABLE (12-3.).
Condition
—
•Refer to 12-5.
to check miswiring and
serial signal error.
•Refer to 12-5.
to check miswiring and
serial signal error.
• Reconnect
connectors.
• Refer to 12-5.
to check inverter/
compressor".
• Check stop valve.
• Refer to 12-5.
"Check of outdoor
thermistors".
Defective outdoor
thermistors can be
identifi ed by checking
the blinking pattern of
LED.
• Reconnect
compressor connector.
• Refer to 12-5. "How
to check inverter/
compressor".
• Check stop valve.
• Reconnect
compressor connector.
• Refer to 12-5. "How
to check inverter/
compressor".
• Check refrigerant
circuit and refrigerant
amount.
• Refer to 12-5. "Check
of LEV".
• Check refrigerant
circuit and refrigerant
amount.
• Check stop valve.
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 12-5. "Check
of outdoor fan motor".
• Refer to 12-5. "Check
of outdoor fan motor".
Refer to 12-5. "Check
of inverter P.C. board".
• Replace the inverter
P.C. board.
• Refer to 12-5.
to check inverter/
compressor".
33
Indoor/outdoor
unit failure
Remedy
mode recall
recall function
function
— —
How
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"How
Outdoor unit
failure mode
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