Mitsubishi Electric MXZ-5B42NA, Руководство по обслуживанию, Страница: 64 / 154

64
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
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON
0.5-second ON
NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.3.
2. LED is lighted during normal operation.
No. Symptom
Indication
Abnormal point /
Condition
Condition Remedy
LED1(Red) LED2(Yellow)
17 'Outdoor
unit stops
and restarts
3 minutes
later' is
repeated. Lighted 8 times
Current sensor
protection
After the operation starts, a short or open circuit
is detected in the current sensor when the
compressor is not operating. • Replace the outdoor power P.C. board .
18
Lighted 11 times
Communication
protection between
P.C. boards 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
control P.C. board and outdoor power P.C. board.
19
Lighted 12 times
Zero cross detecting
circuit protection Zero cross signal cannot be detected when the
compressor begins operating. • Check the connecting wire between outdoor
control P.C. board and outdoor power P.C. board.
20 Outdoor
unit operates
Once Lighted
Primary current
protection
The primary current exceeds 27A. 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 suf fi cient refrigerant.
• Check indoor/outdoor unit air circulation
is not short cycling.
21
Twice Lighted
High-pressure
protection The indoor heat exchanger exceeds 100.4°F
during heating.
Defrosting in cooling
The indoor heat exchanger falls 37.4°F or below
during cooling.
22
3 times Lighted
Discharge
temperature
protection The discharge temperature exceeds 212°F during
operation. • Check refrigerant circuit and refrigerant amount.
• Refer to 11-6. "Check of LEV".
23
4 times
Lighted
Low discharge
temperature
protection
The frequency of the compressor is kept 58 Hz or
more and the discharge temperature is kept under
122°F (cooling) /104°F (heating) for more than 20
minutes • Refer to 11-6. "Check of LEV".
• Check refrigerant circuit and refrigerant amount.
24
5 times Lighted
Cooling high-
pressure protection
The outdoor heat exchanger temperature exceeds
129.2°F during operation. 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 suf fi cient refrigerant.
• Check indoor/outdoor unit air circulation is short
cycling.
7 times Lighted
High Low
Pressure bypass
valve
Cooling evaporating
temperature drop
prevention control
During cooling operation, the temperature of indoor
heat exchanger becomes 37.4°F or less within
1 hour after the compressor starts running, or it
becomes less than 53.6°F - 60.8°F* 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 indoor
fi lters are not clogged.
• Check there is suf fi cient refrigerant.
• Check indoor/outdoor unit air circulation is not
short cycling.
25 Outdoor
unit
operates
normally.
7 times Lighted
High Low
pressure bypass valve
High pressure protection
control at start-up of
heating operation
The room temperature is 75.2°F or more when 1 or
2 unit(s) start(s) the heating operation. This symptom does not mean any
abnormality of the product.
High Low
pressure bypass
valve
Compressor oil tempering
control at start-up of
heating operation Both the following are true:
• The outside temperature is 28.4°F or less when
the heating operation is started.
• [(Discharge temperature) - (Indoor heat
exchanger temperature)] < 41°F
8 times Lighted
Cooling evaporating
temperature
protection
During cooling operation, the temperature of
indoor heat exchanger becomes 44.6°F - 51.8°F*
or less within 1 hour after the compressor
starts running, or it becomes 48.2°F - 62.6°F* or
less later than that.
* It depends on the indoor unit type/model or the
difference between the set temperature and the
room temperature.
9 times Lighted Inverter check mode
The connector of compressor is disconnected.
Inverter check mode starts. • Check the connector of the compressor is
correctly connected.
• Refer to 11-6. "How to check inverter/
compressor".
26 Lighted Lighted Normal
Outdoor control P.C. board (Parts side)
LED1
LED2
Lighted
OBH560G