Mitsubishi Electric MUZ-LN35VGHZ2-E1 Service Manual page 48

3. Table of outdoor unit failure mode recall function
POWER lamp Abnormal point
(Indoor unit) (Failure mode/protection)
OFF None (Normal)
1-time blink Indoor/outdoor
2.5 seconds communication, receiving
OFF error
Indoor/outdoor
communication, receiving
error
2-time blink Outdoor power system
2.5 seconds
OFF
3-time blink Deceleration of the operational
2.5 seconds frequency of the compressor
OFF by the current protection
control
Deceleration of the operational
frequency of the compressor
by the high pressure
protection
Deceleration of the operational
frequency of the compressor
by the overcooling prevention
of the indoor heat exchanger
Deceleration of the operational
frequency of the compressor
by the discharge temperature
protection
Ambient temperature
thermistor
Outdoor heat exchanger
temperature thermistor
4-time blink Overcurrent
2.5 seconds
OFF
Compressor synchronous
abnormality (Compressor
startup failure protection)
5-time blink Discharge temperature
2.5 seconds
OFF
6-time blink High pressure
2.5 seconds
OFF
7-time blink Fin temperature/P.C. board
2.5 seconds temperature
OFF
8-time blink Outdoor fan motor
2.5 seconds
OFF
9-time blink Nonvolatile memory data
2.5 seconds
OFF
Power module (IC700)
OBH768G
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 blink every Thermistor shorts or opens during
2.5 seconds compressor running.
3-time blink
2.5 seconds OFF
4-time blink
2.5 seconds OFF
2-time blink
2.5 seconds OFF
—
Large current flows into power module
11-time blink
2.5 seconds OFF (IC700).
12-time blink 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.
Temperature of fin temperature thermistor
7-time blink
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 blink Nonvolatile memory data cannot be
2.5 seconds OFF read properly.
6-time blink The interface short circuit occurs in the
2.5 seconds OFF output of the power module (IC700).
The compressor winding shorts circuit.
48
NOTE: Blinking patterns of this mode differ from the ones of
TROUBLESHOOTING CHECK TABLE (12-3.).
Condition Remedy
—
•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
identified 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".
Indoor/outdoor
Outdoor unit
unit failure
failure mode
mode recall
recall function
function
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