Mitsubishi Electric MSZ-WR NA Series, Service Manual

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3. Table of outdoor unit failure mode recall function
MUZ-WR09NA MUZ-WR12NA
OPERATION
INDICATOR
upper lamp
(Indoor unit)
Abnormal point
(Failure mode / protection)
LED indication
(Outdoor P.C. board)
Condition Remedy
Indoor/
outdoor unit
failure mode
recall function
Outdoor unit
failure mode
recall function
OFF None (Normal) — — — — —
2-time blink
2.5 seconds
OFF Outdoor power system
—
Overcurrent protection cut-out operates
3 consecutive times within 1 minute
after the compressor gets started.
• Reconnect connectors.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check the stop valve.
○ ○
3-time blink
2.5 seconds
OFF Discharge temperature
thermistor 1-time blink every
2.5 seconds Thermistor shorts or opens during
compressor running.
• Refer to 10-5. "Check
of outdoor thermistors".
Defective outdoor
thermistors can be
identi
fi ed by checking
the blinking pattern of
LED.
○ ○
Defrost thermistor
Fin temperature thermistor 3-time blink
2.5 seconds OFF
P.C. board temperature
thermistor 4-time blink
2.5 seconds OFF
Ambient temperature
thermistor 2-time blink
2.5 seconds OFF
4-time blink
2.5 seconds
OFF Overcurrent 11-time blink
2.5 seconds OFF
Large current fl ows into intelligent
power module/ power module 1.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
• Check the stop valve.
—
○
Compressor synchronous
abnormality (Compressor start-
up failure protection) 12-time blink
2.5 seconds OFF Waveform of compressor current is
distorted.
• Reconnect compressor
connector.
• Refer to 10-5. "How
to check inverter/
compressor".
—
○
5-time blink
2.5 seconds
OFF Discharge temperature
—
Temperature of discharge temperature
thermistor exceeds 241°F (116°C),
compressor stops.
Compressor can restart if discharge
temperature thermistor reads 212°F
(100°C) or less 3 minutes later.
• Check the refrigerant
circuit and the
refrigerant amount.
• Refer to 10-5. "Check
of LEV".
—
○
6-time blink
2.5 seconds
OFF High pressure
—
Temperature of indoor coil thermistor
exceeds 158°F (70°C) in HEAT mode.
Temperature of outdoor heat exchanger
temperature thermistor exceeds 158°F
(70°C) in COOL mode.
• Check the refrigerant
circuit and the
refrigerant amount.
• Check the stop valve.
—
○
7-time blink
2.5 seconds
OFF Fin temperature/ P.C. board
temperature 7-time blink
2.5 seconds OFF Temperature of fi n temperature
thermistor on the inverter P.C. board
exceeds 167 - 176°F (75 - 80°C), or
temperature of P.C. board temperature
thermistor on the inverter P.C. board
exceeds 158 - 167°F (70 - 75°C).
• Check around the
outdoor unit.
• Check the outdoor unit
air passage.
• Refer to 10-5. "Check
of outdoor fan motor".
—
○
8-time blink
2.5 seconds
OFF Outdoor fan motor
—
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor fan
start-up.
• Refer to 10-5. "Check
of outdoor fan motor".
Refer to 10-5. "Check
of inverter P.C. board".
—
○
9-time blink
2.5 seconds
OFF Nonvolatile memory data 5-time blink
2.5 seconds OFF Nonvolatile memory data cannot be
read properly.
• Replace the inverter
P.C. board.
○ ○
10-time blink
2.5 seconds
OFF Discharge temperature
—
Temperature of discharge temperature
thermistor has been 122°F (50°C) or
less for 20 minutes.
• Refer to 10-5. "Check
of LEV".
• Check the refrigerant
circuit and the
refrigerant amount.
—
○
NOTE: Blinking patterns of this mode differ from the ones of
TROUBLESHOOTING CHECK TABLE (10-3.).
OBH819A