MITSUBISHI ELECTRIC MSH-07NV - Manual (Page 49)

49
10-2-1 troubleshooting check table
❈ Before taking measures, make sure that the symptom reappears, for accurate troubleshooting.
Self check table
NO.
1
2
3
4
Abnormal
point
Mis-wiring
Serial sig-
nal
Indoor coil
thermistor
Room
tempera-
ture ther-
mistor
Indoor fan
motor
Outdoor
thermistor
Indication
0.5-second ON
0.5-second OFF
1-time flash
2.5-second OFF
2-time flash
2.5-second OFF
3-time flash
2.5-second OFF
6-time flash
2.5-second OFF
Symptom
Outdoor unit
does not run.
Outdoor unit
does not run.
Indoor fan
repeats 12 sec-
onds ON and 3
minutes OFF.
When the indoor
fan breaks, the
fan keeps stop-
ping.
Outdoor unit
does not run
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 out-
door unit stops for 4 to 5 sec-
onds.
Detect Indoor coil/room tem-
perature thermistor short or
open circuit every 2 seconds
during operation.
When rotational frequency
feedback signal is not emit
during 12-second indoor fan
operation.
When the outdoor 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 thermistor calibration.
● Reconnect connector.
● Check indoor electronic control P.C.board.
● Disconnect connector CN211 and then
check connector CN121 - to make
sure rotational frequency feedback signal
of 1.5V or over exists.
● Check indoor electronic control P.C.
board.
● Check indoor fan motor.
● Reconnect conector.
● Shortage of refrigerent.
● Check outdoor DEICER P.C. board.
2 3
5
Outdoor
power
system
5-time flash
2.5-second OFF
Outdoor unit
does not run
When the compressor opera-
tion is continuosly three times
interruped by overcurrent pro-
tection within 1 minute after
start-up , it stops operation. ● Check the inverter output.
● Check the compressor.
6
Outdoor
control
P.C. board
7-time flash
2.5-second OFF
Outdoor unit
does not run
The outdoor unit stops opera-
tion when it cannot properly
read data in the nonvolatile
memory of the outdoor control
P.C.board.
● Check the outdoor control P.C.board.
7
Outdoor
control
P.C. board
10-time flash
2.5-second OFF
Outdoor unit
does not run
When the indoor unit detects
drain abnormality and the
indoor coil temperature is too
low.
● Check the drain punp.
● Check the drain sensor.
● Check LEV.
8
Outdoor
control
P.C. board
light 2.5-second OFF
flash
Outdoor unit
runs but the
indoor unit does
not run.
When the operation mode of
each rooms is setted
COOL(includes DRY) and
HEAT at same time, it take
precedence the operation
mode runs first.
● Adjust the operation mode.
❈
❈
❈
❈
❈ The indication is shown only when the indoor unit connects with the outdoor unit MXZ-32NV- . E1
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