Mitsubishi Electric MUZ-FH25VEHZ Service Manual page 29

3. Outdoor unit failure 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
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
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)
(FH25/35)
IGBT module (IC700) (FH50)
10-time fl ash Discharge temperature
2.5 seconds
OFF
11-time fl ash Bus-bar voltage (DC)
2.5 seconds
OFF
Each phase current of
compressor
14-time fl ash Stop valve (Closed valve)
2.5 seconds
OFF
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (11-3.).
OBH625A
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) (FH25/35)/ IGBT module
(IC700) (FH50).
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 the fi n temperature
2.5 seconds OFF thermistor on the inverter P.C. board
exceeds 75 ~ 86°C (FH25/35)/75 ~
80°C (FH50), or temperature of P.C.
board temperature thermistor on the
inverter P.C. board exceeds 72 ~ 85°C
(FH25/35)/70 ~ 75°C (FH50).
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor
—
fan start-up.
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)
(FH25/35)/IGBT module (IC700)
(FH50).
The compressor winding shorts circuit.
Temperature of discharge temperature
thermistor has been 50°C or less for
— 20 minutes.
8-time fl ash Bus-bar 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.
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.
• Reconnect
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".
• Refer to 11-5. "Check
of outdoor fan motor".
Refer to 11-5. "Check
of inverter P.C. board".
• 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.
29
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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