Mitsubishi Electric MXZ-A14WV Service Manual page 53

12-3. Troubleshooting check table
MXZ-A14WV -
E1
MXZ-A18WV -
E1
LED 1 (Red)
Lighting
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
Lighting Once Indoor unit and LEV
Lighting Twice Outdoor power system
Lighting 7 times Outdoor control system
Lighting 8 times Active filter module
9 times DC voltage sensing
Lighting
circuit
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
3 times Discharge temperature
Lighting
thermistor
Fin temperature
thermistor
Lighting 4 times
P.C. board temperature
thermistor
Evaporation temperature
Lighting 5 times
thermistor
High-pressure protect
Lighting 5 times
thermistor
Gas pipe temperature A
thermistor
Lighting 10 times
Gas pipe temperature B
thermistor
Twice Goes out Overcurrent protection
3 times Goes out Discharge temperature
overheat protection
Fin temperature
4 times Goes out
overheat protection
4 times Goes out P.C. board temperature
overheat protection
5 times Goes out High-pressure protection When high-pressure protect thermistor detects 69: or more.
LED 2 (Yellow)
Lighting
Symptom: Outdoor unit does not operate.
Detecting method
When the drain abnormality is detected in the indoor unit and the indoor
unit coil temperature is too low, or when any abnormality is detected in
the components of indoor unit.
When the compressor operation has been interrupted by over current
protection continuously three times within 1 minute after start-up.
When the nonvolatile memory data cannot be read properly on the
outdoor electronic control P.C. board.
When active filter module self-protection has been performed
continuously three times.
When DC voltage sensing circuit detects 57V or below or 395V or above.
Symptom: It is repeated that outdoor unit stops and restarts 3 minutes later.
Detecting method
When a short or open circuit occurs in the discharge temperature
thermistor during compressor operating.
When a short or open circuit occurs in the fin temperature thermistor
during compressor operating.
When a short or open circuit occurs in the P.C. board temperature
thermistor during compressor operating.
When a short or open circuit occurs in the evaporation temperature
thermistor during compressor operating.
When high-pressure protect thermistor is short or open while
compressor is operating.
When a short or open circuit occurs in the gas pipe temperature A
thermistor during compressor operating.
When a short or open circuit occurs in the gas pipe temperature B
thermistor during compressor operating.
When overcurrent is applied to the power module.
When the discharge temperature thermistor detects 116: or above.
(Protection will be released at 100: or below.)
When the fin temperature thermistor detects 87: or above.
When the P.C. board temperature thermistor detects 70: or above.
Error mode
Normal
53
Check points
• Check the abnormality indication on the
indoor unit.
• Check the LEV.
• Check the inverter/compressor.
• Replace the outdoor electronic control
P.C. board.
• Replace the outdoor electronic control
P.C. board.
• Replace the outdoor electronic control
P.C. board.
Check points
• Check the characteristic of the discharge
temperature thermistor.
• Check the connector. (CN662)
• Check the characteristic of the fin
temperature thermistor.
• Check the connector. (CN663)
• Replace the outdoor electronic control
P.C. board.
• Check the characteristic of the evaporation
temperature thermistor.
• Check the connector. (CN662)
• Check the characteristic of the high
pressure protect thermistor.
• Check the connector. (CN662)
• Check the characteristic of the gas pipe
temperature A thermistor.
• Check the connector. (CN661)
• Check the characteristic of the gas pipe
temperature B thermistor.
• Check the connector. (CN661)
• Check the inverter/compressor.
• Check the amount of gas.
• Check the indoor/outdoor air flow for
short cycle.
• Check the indoor unit air filter for clogging.
• Check the amount of gas and the
refrigerant cycle.
• Check the outdoor unit air passage.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.
• Check the power module.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.
• Replace the outdoor electronic control
P.C. board.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.