Mitsubishi Electric MXZ-2HA40VF2-E1 Service Manual page 56

Indication
No. Symptom
LED1(Red) LED2(Yellow)
22 'Outdoor unit
13 times
stops and
restarts
23
Lit
3 minutes
later' is
24
repeated.
Lit
25
Lit
26 Outdoor unit
Once
operates.
27
Twice
28
3 times
29
4 times
30
5 times
31
7 times
32
11 times
33 Outdoor
unit
operates
normally.
8 times
34
9 times
35 Lit
NOTE 1. The location of LED is illustrated at the right figure. Refer to 12-7.1.
2. LED is lit during normal operation.
The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the blinking frequency is "2".
ON
2.5-second OFF
OFF
OBH828D
Abnormal point / Con-
dition
Not lit Outdoor fan motor
Current sensor protec-
8 times
tion
Communication
11 times between P.C. boards
protection
Zero cross detecting
12 times circuit (Outdoor power
P.C. board)
Primary current protec-
Lit
tion
High pressure protec-
tion
Lit
Defrosting in cooling
Discharge temperature
Lit
protection
Low discharge
Lit
temperature protection
Cooling high pressure
Lit
protection
High Low
Pressure bypass
valve
Lit
Cooling evaporating
temperature drop
prevention control
M-NET communication
Lit
error
Cooling evaporating
Lit temperature
protection
Lit Inverter check mode
Lit Normal
0.5-second ON
2.5-second OFF
Condition
A failure occurs 3 consecutive times within 30
seconds after the fan gets started.
A short or open circuit is detected in the current
sensor during compressor operating.
Communication error occurs between the outdoor
control P.C. board and outdoor power P.C. board
for more than 10 seconds.
Zero cross signal cannot be detected while the
compressor is operating.
The input current exceeds 13.6 A.
The indoor gas pipe temperature exceeds 45°C
during heating.
The indoor gas pipe temperature falls 3°C or below
during cooling.
The frequency of the compressor is kept 80 Hz or
more and the discharge temperature is kept under
50°C(COOL mode)/40°C(HEAT mode) for more
than 40 minutes.
The frequency of the compressor is kept 80 Hz or
more and the discharge temperature is kept under
39°C for more than 20 minutes.
The outdoor heat exchanger temperature exceeds
58°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.
M-NET adapter P.C. board detects an abnormality
in the communication error.
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 9°C - 17°C* or
less later than that.
* It depends on the indoor unit type/model or the
difference between the set temperature and the
room temperature.
The unit is operated with emergency operation
switch.
—
0.5-second ON
56
Remedy
• Refer to 12-6. "Check of outdoor fan motor".
• Replace the outdoor power P.C. board.
• Check the connecting wire between outdoor con-
trol P.C. board and outdoor power P.C. board.
• Replace the outdoor power P.C. board.
These symptoms do not mean any abnormality of
the product, but check the following points.
• Check if indoor filters are clogged.
• Check if refrigerant is short.
• Check if indoor/outdoor unit air circulation is short
cycled.
• Check refrigerant circuit and refrigerant amount.
• Refer to 12-6. "Check of LEV".
• Refer to 12-6. "Check of outdoor thermistors".
• Refer to 12-6. "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 if indoor filters are clogged.
• Check if refrigerant is short.
• Check if indoor/outdoor unit air circulation is short
cycled.
This symptom does not mean any abnormality of
the product, but check the following points.
• Check the indoor filters are not clogged.
• Check there is sufficient refrigerant.
• Check the indoor/outdoor unit air circulation is not
short cycled.
• Check the connecting wire between M-NET
adapter P.C. board and outdoor control P.C.
board, or terminal block.
This symptom does not mean any abnormality of
the product.
—
—
Outdoor control
P.C. board
(Parts side)
Lit
LED1 LED2