Mitsubishi Electric MXZ-A14WV Service Manual page 56

Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
4 times Goes out P.C. board temperature
overheat protection
5 times Goes out High-pressure protection
Power factor control
8 times Goes out
module protection
9 times Goes out DC voltage protection
13 times Goes out Fan motor protection
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
Once Lighting Current protection
Twice Lighting High-pressure protection When indoor gas pipe temperature exceeds 55˚C during heating.
Twice Lighting Defrosting in cooling
Lighting Discharge temperature
3 times
protection
Lighting Low discharge
4 times
temperature protection
5 times Lighting High-pressure protection
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
Lighting 5 times Defrost thermistor
9 times Lighting Service mode
Symptom: It is repeated that outdoor unit stops and restarts 3 minutes later
Detecting method
When the P.C. board temperature thermistor detects 70: or above.
When outdoor heat exchanger temperature thermistor detects 69: or
more.
When high-pressure switch detects 4MPa or more.
When the overcurrent to power factor controller occurs or the output
voltage from power factor controller becomes 400V or more.
When it's detected that DC voltage becomes 200V or less, or reaches
400V or more.
When fan motor current is 2A or more, or when the abnormality is
detected in the feedback signal from fan motor.
Symptom: Outdoor unit operates (The compressor operates at reduced frequency)
Detecting method
When the outdoor unit input current exceeds 14.5A.
When indoor gas pipe temperature falls to 6˚C or below during cooling.
When the discharge temperature exceeds 104˚C.
When the state with low discharge temperature of which 37˚C or below
in COOL and 35˚C or below in HEAT lasts for 20 minutes.
When outdoor heat exchanger temperature thermistor detects 58: or
more.
Symptom: Outdoor unit operates.
Detecting method
When a short or open circuit occurs in the defrost thermistor during
heating.
When the unit operates EMERGENCY OPERATION.
56
Check points
• 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.
• Check the input voltage.
• Check the inverter.
• Check the voltage of power supply.
• Check the inverter.
• Check the outdoor fan motor.
• Check the fan motor connector.
Check points
These symptoms do not mean any
abnormality of the product, but check
the following points.
• Air filter clogging
• Amount of gas
• Short cycle of indoor/outdoor air flow
Check points
• Check the characteristic of the defrost
temperature thermistor.
• Check the connector. (CN661)