Mitsubishi Electric MXZ-2HA40VF-E1 Service Manual page 49

Indication
No. Symptom
LED1(Red) LED2(Yellow)
22 'Outdoor unit
13 times
stops and
restarts
23
Lit 8 times
3 minutes
later' is
24
repeated.
Lit 11 times
25
Lit 12 times
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
OBH828B
Abnormal point / Con-
dition
A failure occurs 3 consecutive times within 30
Not lit Outdoor fan motor
seconds after the fan gets started.
Current sensor protec- A short or open circuit is detected in the current
tion sensor during compressor operating.
Communication Communication error occurs between the outdoor
between P.C. boards control P.C. board and outdoor power P.C. board
protection for more than 10 seconds.
Zero cross detecting
Zero cross signal cannot be detected while the
circuit (Outdoor power
compressor is operating.
P.C. board)
Primary current protec-
Lit The input current exceeds 13.6 A.
tion
High pressure protec- The indoor gas pipe temperature exceeds 45°C
tion during heating.
Lit
The indoor gas pipe temperature falls 3°C or below
Defrosting in cooling
during cooling.
The frequency of the compressor is kept 80 Hz or
Discharge temperature more and the discharge temperature is kept under
Lit
protection 50°C(COOL mode)/40°C(HEAT mode) for more
than 40 minutes.
The frequency of the compressor is kept 80 Hz or
Low discharge
Lit more and the discharge temperature is kept under
temperature protection
39°C for more than 20 minutes.
Cooling high pressure The outdoor heat exchanger temperature exceeds
Lit
protection 58°C during operation.
High Low During cooling operation, the temperature of indoor
Pressure bypass heat exchanger becomes 3°C or less within 1 hour
valve after the compressor starts running, or it becomes
Lit
Cooling evaporating less than 12°C - 16°C* later than that.
temperature drop * It depends on the difference between the set
prevention control temperature and the room temperature.
M-NET communication M-NET adapter P.C. board detects an abnormality
Lit
error 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
Cooling evaporating
starts running, or it becomes 9°C - 17°C* or
Lit temperature
less later than that.
protection
* 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
Lit Inverter check mode
switch.
Lit Normal
0.5-second ON
2.5-second OFF
Condition
—
0.5-second ON
49
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)
LED1 LED2
Lit