Mitsubishi Electric MXZ-3C54VA, Service Manual

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57
MXZ-6C
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) Lighting Lighting
2-time fl ash Outdoor power system Lighting Lighting Overcurrent protection cut-out operates
3 consecutive times, bus-bar voltage
protection cut-out operates 3 consecu-
tive times, or primary current protection
cut-out operates 3 consecutive times
within 1minute after the compressor
gets started. • Check the connection of
the compressor connecting
wire.
• Refer to 11-6. How to
check inverter/compressor.
• Check the stop valve.
○
3-time fl ash Discharge temperature thermis-
tor Lighting Once Thermistor shorts or opens during
compressor running. • Refer to 11-6. "Check of
outdoor thermistors".
○
Defrost thermistor Lighting Once
Ambient temperature thermistor Lighting Twice
Fin temperature thermistor Lighting 3 times • Replace the power board.
P.C. board temperature thermis-
tor Lighting 4 times • Replace the power board.
Outdoor heat exchanger tem-
perature thermistor Lighting 9 times • Refer to 11-6. "Check of
outdoor thermistors".
4-time fl ash Overcurrent Once Goes out 49 A current fl ows into intelligent power
module.
• Reconnect compressor con-
nector.
• Refer to 11-6. "How to
check inverter/compressor".
• Check the stop valve.
—
Out-of-step protection 9 times Goes out Waveform of compressor current is dis-
torted.
• Refer to 11-6. " How to
check inverter/compressor.
5-time fl ash Discharge temperature Lighting Lighting Discharge temperature exceeds 114 °C
during operation.
Compressor can restart if discharge
temperature thermistor reads 100 °C or
less 3 minutes later. • Check refrigerant circuit and
refrigerant amount.
• Refer to 11-6. "Check of
LEV".
—
6-time fl ash High pressure Lighting Lighting High-pressure is detected with the
high-pressure switch (HPS) during op-
eration. • Check refrigerant circuit and
refrigerant amount.
• Check the stop valve.
—
The outdoor heat exchanger tempera-
ture exceeds 70 °C during cooling or
the indoor gas pipe temperature ex-
ceeds 70°C during heating.
7-time fl ash Fin temperature 3 times Goes out The fin temperature exceeds 110 °C
during operation.
• Check around outdoor unit.
• Check outdoor unit air pas-
sage.
• Refer to 11-6. "Check of
outdoor fan motor".
—
P.C. board temperature 4 times Goes out The P.C. board temperature exceeds
95 °C during operation.
8-time fl ash Outdoor fan motor Lighting Lighting Failure occurs 3 consecutive times
within 30 seconds after the fan gets
started. • Refer to 11-6. "Check of
outdoor fan motor". —
9-time fl ash Nonvolatile memory data Lighting 5 times Nonvolatile memory data cannot be
read properly. • Replace the outdoor control
P.C. board.
• Replace the power board.
○
10-time fl ash Discharge temperature Lighting Lighting The frequency of the compressor is
kept 80Hz or more and the discharge
temperature is kept under 50 °C (cool-
ing)/40 °C (heating) for more than 40
minutes. • Check refrigerant circuit and
refrigerant amount.
• Refer to 11-6. "Check of
LEV".
—