Outdoor Unit - Mitsubishi Electric MUZ-HJ25VA-E1 Service Manual

3. Outdoor unit failure mode table
The upper
lamp of
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
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
9-time fl ash Nonvolatile memory data
2.5 seconds
OFF
Power module
10-time fl ash Discharge temperature
2.5 seconds
OFF
11-time fl ash DC voltage
2.5 seconds
OFF
Each phase current of
compressor
14-time fl ash Stop valve (Closed valve)
2.5 seconds
OFF
4-way valve/
Pipe temperature
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (11-3.).
OBH648
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
11-time fl ash Large current fl ows into power module. Reconnect
2.5 seconds OFF
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 indoor coil thermistor
exceeds 70°C in HEAT mode.
—
Temperature defrost thermistor
exceeds 70°C in COOL mode.
7-time fl ash Temperature of fi n temperature
2.5 seconds OFF thermistor on the inverter P.C. board
exceeds 80 °C or temperature of P.C.
board temperature thermistor on the
inverter P.C. board exceeds 78 °C.
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.
Temperature of discharge temperature
thermistor has been 50°C or less for
— 20 minutes.
8-time fl ash DC voltage of inverter cannot be
2.5 seconds OFF detected normally.
9-time fl ash Each phase current of compressor
2.5 seconds OFF cannot be detected normally.
14-time fl ash Closed valve is detected by
2.5 seconds OFF compressor current.
16-time fl ash The 4-way valve does not work
2.5 seconds OFF properly.
The indoor coil thermistor detects an
abnormal temperature.
Condition
—
•Refer to 11-5.
to check miswiring and
serial signal error.
•Refer to 11-5.
to check miswiring and
serial signal error.
• Reconnect
connectors.
• Refer to 11-5.
to check inverter/
compressor".
• Check stop valve.
• Refer to 11-5.
"Check of outdoor
thermistors".
Defective outdoor
thermistors can be
identifi ed by checking
the blinking pattern of
LED.
•
compressor connector.
• Refer to 11-5. "How
to check inverter/
compressor".
• Check stop valve.
• Reconnect
compressor connector.
• Refer to 11-5. "How
to check inverter/
compressor".
• Check refrigerant
circuit and refrigerant
amount.
• Refer to 11-5. "Check
of LEV".
• Check refrigerant
circuit and refrigerant
amount.
• Check stop valve.
• Check around outdoor
unit.
• Check outdoor unit air
passage.
• Refer to 11-5. "Check
of outdoor fan motor".
• Replace the inverter
P.C. board.
• Refer to 11-5.
to check inverter/
compressor".
• Refer to 11-5. "Check
of LEV".
• Check refrigerant
circuit and refrigerant
amount.
• Refer to 11-5. "How
to check inverter/
compressor".
• Check stop valve.
• Check 4-way valve.
• Replace inverter P.C.
board.
22
Indoor/outdoor
unit failure
Remedy
mode recall
recall function
function
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How
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Outdoor unit

failure mode
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