Indoor Unit - Mitsubishi Electric SUZ-M-VA Series Service Manual

11-3. INSTRUCTION OF TROUBLESHOOTING
Start

Indoor unit

Indoor unit operates.
operates.
Outdoor unit does
Outdoor unit
not operate normally.
does not
operate.
Outdoor unit
Outdoor unit
operates only
does not
in Test Run
operate
operation.
even in
Test Run
operation.
Refer to
Check room
"How to check
temperature
inverter/
thermistor.
compressor".
Refer to 11-7.
"Test point
diagram and
voltage".
Left lamp
Left lamp
Left lamp
Blink ON and
2-time blink
3-time blink
OFF at
Cause:
Cause:
0.5-second
Indoor unit
Indoor unit
intervals
• Trouble of
Cause: • Trouble of
room temp-
Indoor/
indoor fan
erature/
Outdoor unit
motor
indoor coil
• Miswiring
thermistor
or trouble
of serial signal
Refer to 11-6.
Check room
Refer to 11-6.
temperature
"How to
indoor fan
thermistor
check the
motor".
and indoor
miswiring
coil thermis-
and serial
tor.
signal error
Refer to 11-7.
(when
"Test point
outdoor unit
diagram and
does not
voltage".
work)".
OBH843
Indoor unit does
not receive
the signal from
remote controller.
Indoor unit
Unit does
operates, when
not operate
EMERGENCY
normal
OPERATION
operation in
switch is pressed.
COOL or
HEAT mode.
Refer to
Refer to 11-6.
"Check of
"Check of
R.V. coil".
remote controller,
display receiver
P.C. board and
indoor control
P.C. board".
Left lamp
Left lamp
4-time blink
5-time blink
Cause:
Cause:
Indoor unit
Outdoor unit
• Trouble of • Outdoor
indoor unit
power
control system
system
abnormality
Refer to
Replace the
"Check of "How to check
indoor
the inverter/
electronic
compressor".
control
P.C. board.
OPERATION INDICATOR
lamp on the indoor unit is
blinking ON and OFF.
If blinking of OPERATION
Indoor unit
INDICATOR lamp cannot be
does not operate,
checked, it can be checked with
when
failure mode recall function.
EMERGENCY
OPERATION
switch is pressed.
"Test Run operation" means the
operation within 30 minutes after
EMERGENCY OPERATION switch
is pressed.
1. Check indoor / outdoor
connecting wire.
(Check if the power
is supplied to the
indoor unit.)
2. Refer to 11-6.
"Check of indoor
electronic control
P.C. board and indoor
fan motor".
Left lamp
Left lamp
7-time blink
6-time blink
Cause:
Cause:
Outdoor unit
Outdoor unit
• Trouble of
• Trouble of
outdoor
thermistor
control
in outdoor
system
unit
Replace the
Refer to
"Check of inverter P.C.
board or
outdoor
thermistors". the outdoor
electronic
control P.C.
board.
28
Refer to outdoor unit service manual.
Left lamp Left lamp blinks
3 times, then
14-time blink
right lamp
or more
lights on.
Cause:
Cause:
Outdoor unit
Indoor unit
• Other
• Refrigerant
abnormality
leakage
(Sensor detection)
Check • Turn off the
"Flow chart of power after
the detailed FAN operation
outdoor unit is finished.
failure mode (FAN operation
recall function." continues for 3
hours.)
• Check the indoor
unit to detect the
part where re-
frigerant leaks.
• Repair the part
where refrigerant
leaks.
• Turn on the
power again.
• Replace the re-
frigerant sensor
if the problem is
not fixed.
Left lamp blinks
2 times, then
right lamp
lights on.
Cause:
Indoor unit
• Refrigerant
sensor
Connect the
connector of the
refrigerant sensor
properly.
Replace the
refrigerant sensor.