Mitsubishi Electric SEZ-M-DA Series, Руководство по обслуживанию

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106
No. Symptom
Indication
Abnormal point / Con-
dition
Condition Remedy
LED1(Red) LED2(Yellow)
21 'Outdoor unit
stops and
restarts
3 minutes
later' is
repeated.
6 times Not lit Pre-heating protection Overcurrent is detected during pre-heating.
• Reconnect compressor connector.
• Refer to 12-6. "How to check inverter/
compressor".
• Check the power module.
22
8 times Not lit Converter protection
A failure is detected in the operation of the convert-
er during operation.
• Replace the outdoor power P.C. board.
23
9 times Not lit
Bus-bar voltage
protection
The bus-bar voltage exceeds 400 V or falls to low
level during compressor operating.
• Check the voltage of power supply.
• Replace the outdoor power P.C. board or the out-
door control P.C. board.
• Refer to 12-6. "Check of bus-bar voltage".
24
11 times Not lit
Low outside tempera-
ture protection(cooling) The ambient became -12°C or less.
—
25
13 times Not lit Outdoor fan motor
A failure occurs 3 consecutive times within 30
seconds after the fan gets started.
• Refer to 12-6. "Check of outdoor fan motor".
26
Lit 8 times
Current sensor protec-
tion
A short or open circuit is detected in the current
sensor during compressor operating.
• Replace the outdoor power P.C. board.
27
Lit 11 times
Communication
between P.C. boards
protection
Communication error occurs between the outdoor
control P.C. board and outdoor power P.C. board
for more than 10 seconds.
• Check the connecting wire between outdoor con-
trol P.C. board and outdoor power P.C. board.
28
Lit 12 times
Zero cross detecting
circuit (Outdoor power
P.C. board)
Zero cross signal cannot be detected while the
compressor is operating.
• Replace the outdoor power P.C. board.
29 Outdoor unit
operates.
Once Lit
Primary current protec-
tion
The input current exceeds 13.6 A.
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.
30
Twice Lit
High pressure protec-
tion
The indoor gas pipe temperature exceeds 45°C
during heating.
Defrosting in cooling
The indoor gas pipe temperature falls 3°C or below
during cooling.
31
3 times Lit
Discharge temperature
protection
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.
• Check refrigerant circuit and refrigerant amount.
• Refer to 12-6. "Check of LEV".
• Refer to 12-6. "Check of outdoor thermistors".
32
4 times Lit
Low discharge
temperature protection
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.
• Refer to 12-6. "Check of LEV".
• Check refrigerant circuit and refrigerant amount.
33
5 times Lit
Cooling high pressure
protection
The outdoor heat exchanger temperature exceeds
58°C during operation.
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.
34
7 times Lit
High Low
Pressure bypass
valve
Cooling evaporating
temperature drop
prevention control
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.
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.
35
11 times Lit
M-NET communication
error
M-NET adapter P.C. board detects an abnormality
in the communication error.
• Check the connecting wire between M-NET
adapter P.C. board and outdoor control P.C.
board, or terminal block.
36 Outdoor
unit
operates
normally.
8 times Lit
Cooling evaporating
temperature
protection
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.
This symptom does not mean any abnormality of
the product.
37
9 times Lit Inverter check mode
The unit is operated with emergency operation
switch.
—
38 Lit Lit Normal — —
NOTE 1. The location of LED is illustrated at the right figure. Refer to 12-7.2.
2. LED is lighted 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
OFF
2.5-second OFF 2.5-second OFF
0.5-second ON 0.5-second ON
LED1LED2
Lit
Outdoor control
P.C. board
(Parts side)
OBH790D