23
9-3. INSTRUCTION OF TROUBLESHOOTING
*1 "Test Run operation" means the
operation within 30 minutes after
the emergency operation switch
is pressed.
Indoor unit operates.
Outdoor unit does
not operate.
Indoor unit operates.
Outdoor unit does
not operate normally.
Indoor unit does not
receive the signal from
remote controller.
LEFT lamp of the OPERA
-
TION INDICATOR lamp is
blinking ON and OFF.
Outdoor unit
operates only
in Test Run
operation. *1
Outdoor unit
does not
operate even
in Test Run
operation. *1
Unit does not
operate nor-
mal operation
in COOL or
HEAT mode.
Indoor unit
operates, when
the emergency
operation switch
is pressed.
Indoor unit does
not operate, when
the emergency
operation switch is
pressed.
Check room
temperature
thermistor.
Refer to 9-7.
"Test point
diagram and
voltage".
Refer to "How
to check
inverter/com-
pressor".
Refer to
"Check of
R.V. coil".
Refer to 9-6.
"Check of remote
controller and
indoor electronic
control P.C.
board".
1. Check indoor/outdoor
connecting wire.
(Check if the power is
supplied to the indoor
unit.)
2. Refer to 9-6. "Check
of indoor P.C. board
and indoor fan motor".
LEFT lamp
Blink on and
off at 0.5-sec
-
ond intervals
Cause:
Indoor
/Outdoor unit
• Miswiring or
trouble of
serial signal
LEFT lamp
2-time blink
Cause:
Indoor unit
• Trouble
of room
temperature
/ indoor coil
thermistor
LEFT lamp
3-time blink
Cause:
Indoor unit
• Trouble of
indoor fan
motor
LEFT lamp
4-time blink
Cause:
Indoor unit
• Trouble
of indoor
unit control
system
LEFT lamp
5-time blink
Cause:
Outdoor unit
• Outdoor
power sys-
tem abnor-
mality
LEFT lamp
6-time blink
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
LEFT lamp
7-time blink
Cause:
Outdoor unit
• Trouble of
outdoor
control
system
LEFT lamp
14-time blink
or more
Cause:
Outdoor unit
• Other abnormality
Indoor/
Outdoor unit
• Trouble of ther
-
mistors
Start
Refer to 9-6.
"How to
check
miswiring
and serial
signal error".
Check room
temperature
thermistor
and indoor
coil thermis-
tor. Refer to
9-7. "Test
point dia-
gram and
voltage".
Refer to 9-6.
"Check of
indoor fan
motor".
Replace the
indoor
electronic
control P.C.
board.
Refer to
"How to
check
inverter/
compressor".
Refer to
"Check of
outdoor
thermistors".
Replace the
inverter P.C.
board or the
outdoor
electronic
control P.C.
board.
• Check "Flow
chart of the
detailed outdoor
unit failure mode
recall function."
• Check thermis-
tors.
Refer to "Test
point diagram
and voltage"
in the service
manual of
indoor and
outdoor unit.
Refer to outdoor unit service manual.
1. Check of the unit.
*2 There is possibility that diesel explosion may occur due to the air
mixied in the refrigerant circuit.
First, ensure that there are no leakage points on the valves, flare
connections, etc. that allow the air to flow into the refrigerant circuit,
or no blockage points (e.g. clogged or closed valves) in the refrigerant
circuit that cause an increase in pressure.
If there is no abnormal point like above and the system operates cool-
ing and heating modes normally, the indoor thermistor might have a
problem, resulting in false detection.
Check both the indoor coil thermistor and the room temperature ther-
mistor, and replace faulty thermistor(s), if any.
(Do not start the operation again without repair to prevent hazards.)
If blinking of OPERATION
INDICATOR lamp cannot be
checked, it can be checked with
failure mode recall function.
*2
OBHT872
