Mitsubishi Electric SEZ-M-DA Series, Service Manual

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3. Table of outdoor unit failure mode recall function
MXZ-2F
Upper or
left lamp of
OPERATION
INDICATOR
lamp (Indoor
unit)
Abnormal point
(Failure mode/protection)
LED indication
(Outdoor P.C. board)
Condition Remedy
Indoor/
outdoor
unit failure
mode
recall
function
LED 1 LED 2
OFF None (Normal) Not lit Not lit — — —
2-time blink Outdoor power system Lit Lit Overcurrent protection cut-out operates
3 consecutive times within 1 minute after
the compressor gets started.
Compressor protection cut-out
operates 24 consecutive times within
10 seconds after the compressor gets
started.
• Check the compressor connecting
wire.
• Refer to 12-6. "How to check
inverter/compressor".
• Check the stop valve.
○
3-time blink Discharge temperature
thermistor
Lit Once Thermistor shorts or opens during
compressor running.
• Refer to 12-6. "Check of out-
door thermistors".
○
Defrost thermistor Lit Once
○
Ambient temperature
thermistor
Lit Twice
○
Fin temperature thermistor Lit 3 times
○
P.C. board temperature
thermistor
Lit 4 times • Replace the inverter P.C. board.
○
Outdoor heat exchanger
temperature thermistor
Lit 9 times • Refer to 12-6. "Check of out-
door thermistors".
○
4-time blink Overcurrent Once Not lit The overcurrent flows into intelligent
power module.
• Check the compressor connecting
wire.
• Refer to 12-6. "How to check
inverter/compressor".
• Check the stop valve.
—
Compressor Twice Not lit The overcurrent flows into intelligent
power module within 10 seconds after
the compressor gets started.
(The compressor gets restarted in
15 seconds.)
• Check the compressor connecting
wire.
• Refer to 12-6. "How to check
inverter/compressor".
—
9 times Not lit Waveform of compressor current is dis-
torted.
—
5-time blink Discharge temperature Lit Lit Discharge temperature exceeds 116ºC
during operation.
• Check the refrigerant circuit and
the refrigerant amount.
• Refer to 12-6. "Check of LEV".
—
6-time blink High pressure Lit Lit The outdoor heat exchanger temperature
exceeds 70ºC during cooling or the indoor
gas pipe temperature exceeds
70ºC during heating.
• Check the refrigerant circuit and
the refrigerant amount.
• Check the stop valve.
—
7-time blink Fin temperature 3 times Not lit The fin temperature exceeds 90ºC
during operation.
• Check the around outdoor unit.
• Check the outdoor unit air pas-
sage.
—
P.C. board temperature 4 times Not lit The P.C. board temperature exceeds
80ºC during operation.
• Refer to 12-6. "Check of out-
door fan motor".
—
8-time blink Outdoor fan motor Lit Lit Failure occurs 3 consecutive times
within 30 seconds after the fan gets
started.
• Refer to 12-6. "Check of out-
door fan motor". —
9-time blink Nonvolatile memory data Lit 5 times Nonvolatile memory data cannot be read
properly.
• Replace the inverter P.C. board.
○
Power module 7 times Not lit The output of the power module that drove
the compressor was shorted or the wind-
ing of the compressor was shorted.
• Refer to 12-6. "How to check
inverter/compressor".
○
10-time blink Discharge temperature Lit Lit The discharge temperature is kept
under 50ºC (COOL mode)/40ºC (HEAT
mode) for more than 40 minutes.
• Check the refrigerant circuit and
the refrigerant amount.
• Refer to 12-6. "Check of LEV".
—
11-time blink Current sensor 8 times Not lit The sensor circuit of current of
compressor shorts or opens during
compressor operate.
• Replace the inverter P.C. board.
○
Bus-bar voltage 6 times Not lit The bus-bar voltage exceeds 430 V or
falls to 50 V or below during compres-
sor operating.
• Check the power supply.
• Replace the inverter P.C. board.
○
14-time blink Stop valve Lit 12 times The current of compressor is power
module is out of order.
• Check the stop valve.
• Check the refrigerant circuit and
the refrigerant amount.
○
Refrigerant leakage
(Sensor detection)
Lit Lit 1. Refrigerant leaks from the piping or the
heat exchanger in the indoor unit.
2. The following items are used around the
indoor unit.
• Spray (LP gas including Freon, and
whose main ingredient is propane and
butane)
• Aerosol insecticide (including ethanol)
• Air spray painting (including dichlo-
romethane)
• Charcoal (charcoal fire)
• Chemicals (such as ethanol)
• Turn off the power after the in-
door unit finishes its FAN opera -
tion.
(The FAN operation continues for 3
hours.)
• Check the indoor unit to detect
the part where refrigerant leaks.
• Repair the part where refrigerant
leaks.
• Turn on the power again.
• Replace the refrigerant sensor if
the problem is not fixed.
○
NOTE: Blinking patterns of this mode differ from the ones of
Troubleshooting check table (12-4).
OBH790D