Mitsubishi Electric MXZ-2C30VA Service Manual page 82

Indication
No. Symptom
LED1(Red) LED2(Yellow)
17 'Outdoor
unit stops Lighting
and restarts
3 minutes
18
later' is
Lighting
repeated.
19
Lighting 12 times
20 Outdoor
unit operates
Once
21
Twice
22
3 times
23
4 times
24
5 times
7 times
8 times
25 Outdoor
unit
operates
normally.
7 times
9 times
26 Lighting
NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.2.
2. LED is lighted during normal operation.
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is "2".
ON
2.5-second OFF
OFF
Abnormal point /
Condition
Current sensor
8 times
protection
Communication
11 times protection between
P.C. boards
Zero cross detecting
circuit protection
Primary current
Lighting
protection
High-pressure
protection
Lighting
Defrosting in cooling
Discharge
Lighting temperature
protection
Low discharge
Lighting temperature
protection
Cooling high-
Lighting
pressure protection
High Low
Pressure bypass
valve
Lighting
Cooling evaporating
temperature drop
prevention control
Cooling evaporating
Lighting temperature
protection
High Low
pressure bypass
valve
High pressure
protection control at
start-up of heating
operation
Lighting
High Low
pressure bypass
valve
Compressor oil
tempering control at
start-up of heating
operation
Lighting Inverter check mode
Lighting Normal
0.5-second ON
2.5-second OFF
Condition
After the operation starts, a short or open
circuit is detected in the current sensor when
the compressor is not operating.
Communication error occurs between the
outdoor control P.C. board and power board
for more than 10 seconds.
Zero cross signal cannot be detected when
the compressor begins operating.
The primary current exceeds 27A.
The indoor heat exchanger exceeds 38°C during
heating.
The indoor heat exchanger falls 3°C or below
during cooling.
The discharge temperature exceeds 100°C
during operation.
The frequency of the compressor is kept 58
Hz or more and the discharge temperature is
kept under 50°C (cooling) /40°C (heating) for
more than 20 minutes
The outdoor heat exchanger temperature
exceeds 54°C during operation.
During cooling operation, the temperature
of indoor heat exchanger becomes 3°C or
less within 1 hour after the compressor starts
running, or it becomes less than 12°C - 16°C
later than that.
* It depends on the difference between the set
temperature and the room temperature.
During cooling operation, the temperature of
indoor heat exchanger becomes 7°C - 11°C
or less within 1 hour after the compressor
starts running, or it becomes 13°C - 17°C or
less later than that.
* It depends on the difference between the set
temperature and the room temperature.
The room temperature is 24°C or more when
1 or 2 unit(s) start(s) the heating operation.
Both the following are true:
• The outside temperature is -2°C or less
when the heating operation is started.
• [(Discharge temperature) - (Indoor heat
exchanger temperature)] < 5°C
The connector of compressor is
disconnected.
Inverter check mode starts.
82
Remedy
• Replace the power board.
• Check the connecting wire between outdoor
control P.C. board and power board.
• Check the connecting wire between outdoor
control P.C. board and power board.
These symptoms do not mean any
abnormality of the product, but check the
following points.
• Check indoor fi lters are not clogged.
• Check there is suffi cient refrigerant.
• Check indoor/outdoor unit air circulation
is not short cycling.
• Check refrigerant circuit and refrigerant
amount.
• Refer to 11-6. "Check of LEV".
• Refer to 11-6. "Check of LEV".
• Check refrigerant circuit and refrigerant
amount.
This symptom does not mean any
abnormality of the product, but check the
following points.
• Check indoor fi lters are not clogged.
• Check there is suffi cient refrigerant.
• Check indoor/outdoor unit air circulation is
short cycling.
This symptom does not mean any
abnormality of the product, but check the
following points.
• Check indoor fi lters are not clogged.
• Check there is suffi cient refrigerant.
• Check indoor/outdoor unit air circulation is
not short cycling.
This symptom does not mean any
abnormality of the product.
• Check the connector of the compressor is
correctly connected.
• Refer to 11-6. "How to check inverter/
compressor".
Outdoor control P.C. board (Parts side)
Lighting
0.5-second ON
LED2
LED1