Mitsubishi Electric MSZ-FA25VA Service Manual page 18

Mitsubishi ilmalämpöpumput huoltaa ja korjaa: Jäähdytinpalvelu RefGroup Oy
9-4. Troubleshooting check table
NOTE : Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
Self check table
Abnormal
No. Operation indicator lamp
point
POWER lamp flashes.
0.5-second ON
Mis-Wiring
or serial
1
signal
0.5-second OFF
Outdoor
control
POWER lamp lights up
2
system
Indoor coil
POWER lamp flashes.
thermistor
2-time flash
3
Room
tempera-
2.5-second OFF
ture
thermistor
POWER lamp flashes.
3-time flash
Indoor fan
4
motor
2.5-second OFF
POWER lamp flashes.
5-time flash
Outdoor
power
5
system
2.5-second OFF
POWER lamp flashes.
6-time flash
Outdoor
6
thermistors
POWER lamp flashes.
7-time flash
Outdoor
control
7
system
POWER lamp flashes.
14-time flash
Other
8
abnonmality
2.5-second OFF
NOTE : When the indoor unit has started operation and the above detection method has detected an abnormality (the first
detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with
OPERATION INDICATOR lamp flashing.
· Flashing of POWER lamp indicates abnormalities.
Lighted
Blinking
Not lighted
Symptom
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
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Detection method
When the serial signal form the outdoor unit is
not received for a maximum of 6 minutes.
When it cannot properly read data in the
nonvolatile memory of the inverter P.C. board
or the outdoor electronic control P.C. board.
When the indoor coil or the room temperature
thermistor is short or open circuit.
When the rotational frequency feedback
signal is not emit during the indoor fan
operation.
When it consecutively occurs 3 times that the
compressor stops for overcurrent protection or
start-up failure protection witth in 1 minute
after start-up.
When the outdoor thermistors short or open
circuit during the compressor operation.
When it cannot properly read data in the
nonvolatile memory of the inverter P.C. board
or the outdoor electronic control P.C. board.
An abnormality other than above mentioned is
deteced.
18
Check point
• Refer to 9-6.D "How to check
mis-wiring and serial signal
error".
• Check the blinking pattern of
the LED on the inverter P.C.
board or the outdoor lectronic
control P.C. board.
• Refer to 9-7.the
characteristics of indoor coil
thermistor, and the room
temperature thermistor.
• Refer to 9-7.A "Check of
indoor fan motor".
• Refer to "Check of inverter/
compressor".
Refer to service manual
OB372 or OB377.
Check the stop valve.
• Refer to "Check of outdoor
thermistor".
Refer to service manual
OB372 or OB377.
• Replace the inverter P.C.
board or the outdoor
electronic control P.C. board.
Refer to service manual
OB372 or OB377.
• Confirm the abnormarity in
detail using the failure mode
recall function.