Mitsubishi Electric Mr.Slim MSY-D30NA, Service Manual

Page: 62 / 214

28
No. Symptom
Indication
Abnormal point / Condition Condition Remedy
LED1
(Red) LED2
(Yellow)
20
Outdoor
unit oper-
ates.
Once Lighting
Primary current protection The input current exceeds 15 A.
These symptoms do not mean any abnormality of
the product, but check the following points.
Check if indoor
fi lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air circulation is short
cycled.
•
•
•
•
Secondary current protection The current of the compressor exceeds 15 A.
21 Twice Lighting
High-pressure protection
(MUZ) The indoor gas pipe temperature exceeds 113°F (45°C) dur-
ing heating.
Defrosting in cooling
The indoor gas pipe temperature falls 37°F (3°C) or below
during cooling.
22 3 times Lighting
Discharge temperature protec-
tion The discharge temperature exceeds 212°F (100°C) during
operation.
Check refrigerant circuit and refrigerant amount.
Refer to 10-5. "Check of LEV".
Refer to 10-5. "Check of outdoor thermistors". •
•
•
23 4 times Lighting
Low discharge temperature
protection
The frequency of the compressor is kept 80 Hz or more and
the discharge temperature is kept under 102°F (39°C) for
more than 20 minutes.
Refer to 10-5. "Check of LEV".
Check refrigerant circuit and refrigerant amount. •
•
24 5 times Lighting
Cooling high-pressure protec-
tion The outdoor heat exchanger temperature exceeds 136°F (58
°C) during operation.
This symptom does not mean any abnormality of
the product, but check the following points.
Check if indoor
fi lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air circulation is short
cycled.
•
•
•
•
25
Outdoor
unit oper-
ates
9 times Lighting Inverter check mode The unit is operated with emergency operation switch. –
26 Lighting Lighting Normal – –