Mitsubishi Electric MXZ-2C30VA Service Manual page 92

MXZ-6C
Indication
No. Symptom
LED1(Red) LED2(Yellow)
1 Outdoor
Lighted
unit does
not operate.
2
Lighted
3
Lighted
4
Lighted
5
Lighted
6
Lighted
7
Lighted
8
Lighted
9
Lighted
Lighted
10 'Outdoor
unit stops
and restarts
Twice Not lighted
3 minutes
later' is
repeated.
11
3 times Not lighted
12
4 times Not lighted
13
5 times Not lighted
7 times Not lighted
15
9 times Not lighted
10 times Not lighted
11 times Not lighted
12 times Not lighted
16
13 times Not lighted
OBH584E
Abnormal point /
Condition
Once LEV and drain pump
Outdoor power
Twice
system
Discharge
3 times temperature
thermistor
Fin temperature
thermistor
4 times
P.C board
temperature
thermistor
Ambient temperature
thermistor
Outdoor heat
5 times exchanger
temperature
thermistor
Defrost thermistor
Nonvolatile memory
7 times data (Outdoor control
P.C. board)
8 times Current sensor
Communication error
11 times
between P.C. boards
Zero cross detecting
12 times
circuit
Nonvolatile memory
data (power board (MXZ-
14 times
6C120VA)/outdoor power
P.C. board (MXZ-6C122VA))
IPM protection
Overcurrent
Discharge
temperature
protection
Fin temperature
protection
P.C. board
temperature
protection
High-pressure
protection
Out-of-step
protection
Bus-bar voltage
protection
Zero cross loss
Low out side
temperature
protection (cooling)
Primary current
protection
Outdoor fan motor
Condition
The indoor unit detects an abnormality in the LEV
and drain pump.
Overcurrent protection cut-out operates 3
consecutive times, bus-bar voltage protection cut-
out operates 3 consecutive times, or primary current
protection cut-out operates 3 consecutive times
within 1minute after the compressor gets started.
A short circuit is detected in the thermistor during
operation, or an open circuit is detected in the
thermistor 10 minutes after compressor start-up.
A short or open circuit is detected in the
thermistor during operation.
A short or open circuit is detected in the
thermistor during operation.
The nonvolatile memory data cannot be read
properly.
Current sensor has been short or open circuited
for 120 seconds.
Communication error occurs twice between the
outdoor control P.C. board an dpower board (MXZ-
6C120VA)/outdoor power P.C. board (MXZ-
6C122VA) for more than 10 seconds.
The protection cut-out of the zero cross detecting
circuit operates 3 consecutive times.
The nonvolatile memory data cannot be read
properly.
Overcurrent is detected when the frequency of the
compressor is 1 Hz or less.
Overcurrent is detected when the frequency
of the compressor is more than 1 Hz.
Discharge temperature exceeds 114°C during
operation. Compressor can restart if discharge
temperature thermistor reads 100°C or less 3
minutes later.
The fin temperature exceeds 110°C during
operation.
The P.C. board temperature exceeds 95°C during
operation.
High-pressure is detected with the high-pressure
switch (HPS) during operation.
The outdoor heat exchanger temperature exceeds
70°C during cooling or indoor gas pipe temperature
exceeds 70°C during heating.
The waveform of compressor current is distorted.
The bus-bar voltage exceeds 400 V or falls to
300 V or below while the compressor is
operating.
Zero cross signal cannot be detected while the
compressor is operating.
The ambient temperature became -12°C or less.
The primary current exceeds 37 A for 10
seconds.
The fan motor speed is 50 rpm or less or 1500 rpm
or more for 1 minute, or the fan motor speed is
100 rpm or less for 15 seconds when the outside
temperature is 20 °C or more.
92
Remedy
• Refer to 11-6. "Check of LEV".
• Check the drain pump of the indoor unit.
• Check the connection of the compressor
connecting wire.
• Refer to 11-6. "How to check inverter/
compressor".
• Check the stop valve.
• Refer to 11-6. "Check of outdoor
thermistors".
• Replace the power board (MXZ-6C120VA)/
outdoor power P.C. board (MXZ-6C122VA).
• Replace the power board (MXZ-6C120VA)/
outdoor power P.C. board (MXZ-6C122VA).
• Refer to 11-6. "Check of outdoor
thermistors".
• Replace the control P.C. board (MXZ-6C120VA)/
outdoor control P.C. board(MXZ-6C122VA).
• Replace the power board (MXZ-6C120VA)/
outdoor power P.C. board(MXZ-6C122VA).
• Check the connecting wire between control P.C.
board (MXZ-6C120VA)/outdoor control P.C.
board(MXZ-6C122VA) and power board (MXZ-
6C120VA)/outdoor power P.C. board (MXZ-
6C122VA).
• Check the connecting wire between control P.C.
board (MXZ-6C120VA)/outdoor control P.C.
board(MXZ-6C122VA) and power board (MXZ-
6C120VA)/outdoor power P.C. board (MXZ-
6C122VA).
• Replace the power board (MXZ-6C120VA)/
outdoor power P.C. board (MXZ-6C122VA).
• Reconnect compressor connector.
• Refer to 11-6. "How to check inverter/
compressor".
• Check the stop valve.
• Check the power module (PAM module).
• Check the amount of gas and refrigerant
circuit.
• Refer to 11-6. "Check of LEV".
•Check refrigerant circuit and refrigerant
amount.
• Check the amount of gas and the
refrigerant circuit.
• Check the stop valve.
• Reconnect connector of compressor.
• Refer to 11-6. "How to check inverter/
compressor".
• Check the voltage of power supply.
• Replace the power board (MXZ-6C120VA)/
outdoor power P.C. board (MXZ-6C122VA) or
the control P.C. board (MXZ-6C120VA)/outdoor
control P.C. board (MXZ-6C122VA) .
• Refer to 11-6. "Check of bus-bar voltage".
• Refer to 11-6. "Check of outdoor fan motor".