Mitsubishi Electric MXZ-A14WV Service Manual page 54

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
Discharge temperature
3 times Lighting
protection
Lighting Low discharge
4 times
temperature protection
5 times Lighting High-pressure protection When high-pressure protect thermistor detects 58: or more.
6 times Lighting Overload protection
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
Lighting 5 times Defrost thermistor
Lighting 6 times Power factor detection
8 times Lighting Active filter module protection When active filter module self-protection has been performed.
9 times Lighting Service mode
Symptom: Outdoor unit operates (The compressor operates at reduced frequency)
Detecting method
When the outdoor unit input current exceeds 13A.
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 for lasts 20 minutes.
When the compressor load exceeds the specified value.
Symptom: Outdoor unit operates.
Detecting method
When a short or open circuit occurs in the defrost thermistor during
heating.
When the compressor power factor cannot be detected.
When operating unit with compressor relay connector disconnected.
54
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. (CN662)
• Check the compressor wiring.