Mitsubishi Electric SEZ-M-DA Series, Service Manual

Page: 103 / 130

103
MXZ-2F
No. Symptom
Indication
Abnormal point / Con-
dition
Condition Remedy
LED1(Red) LED2(Yellow)
1
Outdoor unit
does not op-
erate.
Lit Once LEV and drain pump
The indoor unit detects an abnormality in the LEV
and drain pump.
• Refer to 12-6. "Check of LEV".
• Check the drain pump of the indoor unit.
2 Lit Twice Outdoor power system
Overcurrent protection cut-out operates 3 consecu-
tive times within 1 minute after the compressor gets
started.
• Check the connection of the compressor connect-
ing wire.
• Refer to 12-6. "How to check inverter/compres-
sor".
• Check the stop valve.
3 Lit 3 times
Discharge temperature
thermistor
A short circuit is detected in the thermistor during
operation, or when an open circuit is detected in the
thermistor after 10 minutes of compressor startup.
• Refer to 12-6. "Check of outdoor thermistors".
4 Lit 4 times
Fin temperature
thermistor
A short or open circuit is detected in the thermistor
during operation.
• Refer to 12-6. "Check of outdoor thermistors".
P.C board temperature
thermistor
• Replace the inverter P.C. board.
5 Lit 5 times
Ambient temperature
thermistor
A short or open circuit is detected in the thermistor
during operation.
• Refer to 12-6. "Check of outdoor thermistors".
Outdoor heat ex-
changer temperature
thermistor
A short circuit is detected in the thermistor during
operation, or when an open circuit is detected in
the thermistor after 5 minutes (in cooling) and 10
minutes (in heating) of compressor startup.
Defrost thermistor
A short circuit is detected in the thermistor during
operation, or when an open circuit is detected in the
thermistor after 5 minutes of compressor startup.
6 Lit 7 times
Nonvolatile memory
data
The nonvolatile memory data cannot be read prop-
erly.
• Replace the inverter P.C. board.
7 Lit 11 times
Stop valve
Closed valve
Closed valve is detected by compressor current.
( MXZ-2F33VF, MXZ-2F33VF2, MXZ-2F33VF3 )
• Check the stop valve.
8 Lit 17 times
Outdoor refrigerant
system abnormality
A closed valve and air trapped in the refrigerant
circuit are detected based on the temperature
sensed by the indoor and outdoor thermistors and
the current of the compressor.
• Check for a gas leak in a connecting piping etc.
• Check the stop valve.
• Refer to 12-6. "Check of outdoor refrigerant
circuit".
9 Lit 18 times
Detection of refrigerant
(Indoor unit)
1. Refrigerant leaks from the piping or the heat
exchanger in the indoor unit.
2. The following items are used around the in-
door unit.
• Spray (LP gas including Freon, and whose
main ingredient is propane and butane)
• Aerosol insecticide (including ethanol)
• Air spray painting (including dichloromethane)
• Charcoal (charcoal fire)
• Chemicals (such as ethanol)
• Turn off the power after the indoor unit fin -
ishes its fan operation.
(The fan operation continues for 3 hours.)
• Check the indoor unit to detect the part
where refrigerant leaks.
• Repair the part where refrigerant leaks.
• Turn on the power again.
• Replace the refrigerant sensor if the problem
is not fixed.
10 Lit 19 times
Abnormality of refriger-
ant leakage sensor
(Indoor unit)
The refrigerant sensor mounted on the indoor
unit does not work.
The refrigerant sensor is not connected prop-
erly or the wire is broken.
• Connect the connector of the refrigerant sen-
sor properly.
• Replace the refrigerant sensor.
11 Lit 20 times
Incompatible unit com-
bination error
The indoor unit which is not compatible with
the outdoor unit is connected.
• Replace the indoor unit with the one which is
compatible with the outdoor unit.
12
'Outdoor unit
s t o p s a n d
r e s t a r t s 3
minutes later'
is repeated.
Twice Not lit Overcurrent
14 A ( MXZ-2F33VF, MXZ-2F33VF2, MXZ-
2F33VF3 )/18 A ( MXZ-2F42VF, MXZ-2F42VF2,
MXZ-2F42VF3, MXZ-2F53VF/VFH, MXZ-
2F53VF2/VFH2, MXZ-2F53VF3/VFH3 ) current
flows into intelligent power module.
• Reconnect compressor connector.
• Refer to 12-6. "How to check inverter/
compressor".
• Check the stop valve.
13 3 times Not lit
Discharge
temperature
protection
Discharge temperature exceeds 116°C during
operation. Compressor can restart if discharge
temperature thermistor reads 100°C or less 3
minutes later.
• Check the amount of gas and the refrigerant
circuit.
• Refer to 12-6. "Check of LEV".
14 4 times Not lit
Fin temperature
protection
The fin temperature exceeds 90°C during operation.
• Check the refrigerant circuit and the refrigerant
amount.
• Refer to 12-6. "Check of outdoor fan motor".
P.C. board temperature
protection
The P.C. board temperature exceeds 78°C during
operation.
15 5 times Not lit
High pressure protec-
tion
The outdoor heat exchanger temperature exceeds
70°C during cooling or indoor gas pipe temperature
exceeds 70°C during heating.
• Check the amount of gas and the refrigerant cir-
cuit.
• Check the stop valve.
16 9 times Not lit
Bus-bar voltage
protection
The bus-bar voltage exceeds 430 V or falls to 50 V
or below during compressor operating.
• Replace the inverter P.C. board.
17 13 times Not lit Outdoor fan motor
Failure occurs 3 consecutive times within 30 sec-
onds after the fan gets started.
• Refer to 12-6. "Check of outdoor fan motor".
18 8 times Not lit
Current sensor
protection
A short or open circuit is detected in the
current sensor during compressor operating.
• Replace the inverter P.C. board.
19 10 times Not lit Compressor
The compressor does not synchronize with the
operating power.
• Reconnect compressor connector.
• Refer to 12-6. "How to check inverter/
compressor".
• Check the stop valve.
12-4. TROUBLESHOOTING CHECK TABLE
OBH790D