Mitsubishi Electric MCFH-13NV-E3 Service Manual page 28

1. troubleshooting check table
w Before taking measures, make sure that the symptom reappears, for accurate troubleshooting.
Self check table
Abnormal
NO.
point
0.5-second ON
Mis-wiring
0.5-second OFF
1
1-time flash
Serial
signal
2.5-second OFF
Indoor coil
2-time flash
thermistor
2
Room
temperatur
e 2.5-second OFF
thermistor
5-time flash
Outdoor
power
3
system
6-time flash
Defrost
4
thermistor
7-time flash
Out door
control
5
system
error
10-time flash
Out door
refrigeran
t
6
system
error
Those indications are shown only when the indoor unit connects with the outdoor unit MXZ-32RV-
Indication
Outdoor unit
does not run.
Outdoor unit
does not run.
Outdoor unit
does not run
2.5-second OFF
Outdoor unit
does not run
2.5-second OFF
Outdoor unit
does not run
2.5-second OFF
Outdoor unit
does not run
2.5-second OFF
Symptom Detect method
When serial signal stops for 4
to 5 seconds after 1st on of
52C relay by POWER turning
on.
When serial signal from
outdoor unit stops for 4 to 5
seconds.
Detect Indoor coil/room
temperature thermistor short
or open circuit every 8
seconds during operation.
When compressor has
stopped due to over current
protection or start-up failure
protection 3 times in a row
within 1 min. after start-up.
When the defrost thermistor
shorts or opens after the
compressor start-up.
When the compressor
operation has
interrupted by LEV protection
continuously 5 times, the
compressor stops operation.
28
Check point
Check switch SW2-2.(MU type or MUH
type)
Check wiring (visual check and
conductivity check).
Check indoor electronic control
P.C.board.
Check outdoor DEICER P.C. board.
Check electrical parts.
Check resistance of thermistor.
Reconnect connector.
Check indoor electronic control P.C.board.
Check inverter and compressor.
Check outdoor DEICER P.C. board.(MUH)
Check outdoor control P.C. board. (MXZ)
Check resistance of thermistor.
Reconnect connector.
Check outdoor control P.C. board.
Amount of gas.
been
Outdoor control P. C. board.
Contact of LEV board connectors.
.
E1