Mitsubishi MCFH-24NV - Troubleshooting Check Table

44
11-2-1. troubleshooting check table
OPERATION
INDICATOR
lamp
Before taking measures, make sure that the symptom reappears, for accurate troubleshooting.
Self check table
NO.
1
2
3
Abnormal
point
Mis-wiring
Serial sig-
nal
Indoor coil
thermistor
Room
tempera-
ture ther-
mistor
Defrost
thermistor
Indication
0.5-second ON
0.5-second OFF
1-time flash
2.5-second OFF
2-time flash
2.5-second OFF
6-time flash
2.5-second OFF
Symptom
Outdoor unit
does not run.
Outdoor unit
does not run.
Outdoor unit
does not run
Detect method
When serial signal stops for 4
to 5 seconds after 1st on of
52C contactor by POWER
turning on.
When serial signal from out-
door unit stops for 4 to 5 sec-
onds.
Detect Indoor coil/room tem-
perature thermistor short or
open circuit every 8 seconds
during operation.
When the defrost thermistor
shorts or opens after the com-
pressor start-up.
Check point
● Check wiring (visual check and conductiv-
ity check).
● Check indoor electronic control
P.C.board.
● Check outdoor DEICER P.C. board.
● Check electrical parts.
● Check resistance of thermistor.
● Re-connect connector.
● Check indoor electronic control P.C.board.
● Check outdoor DEICER P.C. board.
● Check resistance of thermistor.
● Re-connect connector.
4
Outdoor
power
system
5-time flash
2.5-second OFF
Outdoor unit
does not run
When the compressor opera-
tion is continuously three times
interrupted by over current
protection within 1 minute after
start-up , it stops operation.
● Check the inverter output.
● Check the compressor.
5
Outdoor
control
P.C. board
MCFH-
24NV only
7-time flash
2.5-second OFF
Outdoor unit
does not run
When it cannot properly read
data in the nonvolatile memory
of the outdoor control
P.C.board.
● Check the outdoor control P.C.board.
6
Outdoor
refrigerant
system
error
10-time flash
2.5-second OFF
Outdoor unit
does not run
When the compressor opera-
tion has been interrupted by
LEV protection continuously 5
minutes, the compressor stops
operation.
● Amount of gas.
● Check the outdoor control P.C. board.
● Contact of LEV board connectors.
❈
❈
❈
❈The indication is shown only when the indoor unit connects with the outdoor unit MXZ-32SV- .
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