No.

Symptom

Indication

 

Abnormal point / Condition

Condition

Correspondence

LED1(Red)

LED2(Yellow)

 

 

 

 

 

 

 

20

Outdoor unit

Once

Lighting

 

Primary current protection

When the input current exceeds 15A.

These symptoms do not mean any abnormality of the

operates.

 

 

 

product, but check the following points.

 

Secondary current protection

When the current of the compressor exceeds 15A.

 

 

 

 

 

 

 

 

 

 

• Check if indoor filters are clogged.

 

 

 

 

 

 

 

 

 

Twice

Lighting

 

High-pressure protection

When the indoor gas pipe temperature exceeds 45: during heating.

• Check if refrigerant is short.

21

 

 

 

 

• Check if indoor/outdoor unit air circulation is short cycled.

 

 

 

 

Defrosting in cooling

When the indoor gas pipe temperature falls 3: or below during cooling.

 

 

 

 

 

 

 

 

 

 

 

22

 

3 times

Lighting

 

Discharge temperature

 

• Check refrigerant circuit and refrigerant amount.

 

 

When the discharge temperature exceeds 100: during operation.

• Refer to 10-6.G"Check of LEV".

 

 

protection

 

 

 

 

 

 

• Refer to 10-6.B"Check of outdoor thermistors".

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Low discharge

When the frequency of the compressor is kept 80Hz or more and

• Refer to 10-6.G"Check of LEV".

23

 

4 times

Lighting

 

the discharge temperature is kept under 39: for more than 20

 

 

temperature protection

• Check refrigerant circuit and refrigerant amount.

 

 

 

 

 

minutes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This symptom does not mean any abnormality of the

 

 

 

 

 

Cooling high-pressure

When the outdoor heat exchanger temperature exceeds 58:

product, but check the following points.

24

 

5 times

Lighting

 

• Check if indoor filters are clogged.

 

 

protection

during operation.

 

 

• Check if refrigerant is short.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• Check if indoor/outdoor unit air circulation is short cycled.

 

 

 

 

 

 

 

 

 

Outdoor unit

 

 

 

 

 

 

25

operates

9 times

Lighting

 

Inverter check mode

When the unit is operated with emergency operation switch.

-

26

Lighting

Lighting

Normal

-

-

22

Page 22
Image 22
Mitsubishi Electronics MUZ-GB50VA service manual Once Lighting