32
12-3. TROUBLESHOOTING CHECK TABLE
No.
Symptom
LED indication
Abnormal point/
Condition
Condition
Remedy
1
Outdoor unit
does not
operate.
1-time blink every
2.5 seconds
Outdoor power
system
Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started.
• Reconnect connector of
compressor.
• Refer to 12-5. "How to check
inverter/compressor".
• Check stop valve.
2
Outdoor thermistors
Discharge temperature thermistor, fin temperature thermistor,
defrost thermistor, outdoor heat exchanger temperature ther-
mistor or ambient temperature thermistor shorts or opens dur-
ing compressor running.
• Refer to 12-5. "Check of outdoor
thermistors".
P.C. board temperature thermistor shorts or opens during
compressor running.
• Replace inverter P.C. board.
3
Outdoor control
system
Nonvolatile memory data cannot be read properly.
(POWER lamp of the indoor unit lights up or blinks 7-time.)
• Replace inverter P.C. board.
4
6-time blink
2.5 seconds OFF
Serial signal
The communication fails between the indoor and outdoor unit
for 3 minutes.
• Refer to 12-5. "How to check
miswiring and serial signal error.
5
11-time blink
2.5 seconds OFF
Stop valve/
Closed valve
Closed valve is detected by compressor current.
• Check stop valve.
6
14-time blink
2.5 seconds OFF
Outdoor unit
(Other abnormality)
Outdoor unit is defective.
• Refer to 12-2.2. "Flow chart of the
detailed outdoor unit failure mode
recall function".
7
16-time blink
2.5 seconds OFF
4-way valve/
Pipe temperature
The 4-way valve does not work properly.
The indoor coil thermistor detects an abnormal temperature.
• Refer to 12-5. "Check of R.V.
coil".
• Replace the inverter P.C. board.
8
17-time blink
2.5 seconds OFF
Outdoor refrigerant
system abnormality
A closed valve and air trapped in the refrigerant circuit are de-
tected based on the temperature sensed by the indoor and
outdoor thermistors and the current of the compressor.
• Check for a gas leak in a connect-
ing piping etc.
• Check the stop valve.
• Refer to 12-5. "Check of outdoor
refrigerant circuit".
9
'Outdoor unit
stops and re-
starts 3 min-
utes later' is
repeated.
2-time blink
2.5 seconds OFF
Overcurrent
protection
Large current flows into power module (IC700).
• Reconnect connector of compres-
sor.
• Refer to 12-5. "How to check
inverter/compressor".
• Check stop valve.
10
3-time blink
2.5 seconds OFF
Discharge tempera-
ture overheat
protection
Temperature of discharge temperature thermistor exceeds
116°C, compressor stops. Compressor can restart if discharge
temperature thermistor reads 100°C or less 3 minutes later.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 12-5. "Check of LEV".
11
4-time blink
2.5 seconds OFF
Fin temperature /P.C.
board temperature
thermistor overheat
protection
Temperature of fin temperature thermistor on the heat sink ex
-
ceeds 75 ~ 86°C (
RW25/35
)/75 ~ 80°C (
RW50
) or temperature
of P.C. board temperature thermistor on the inverter P.C. board
exceeds 72 ~ 85°C (
RW25/35
)/70 ~ 75°C (
RW50
).
• Check around outdoor unit.
• Check outdoor unit air passage.
• Refer to 12-5. "Check of outdoor
fan motor".
12
5-time blink
2.5 seconds OFF
High pressure
protection
Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
thermistor exceeds 70°C in COOL mode.
• Check refrigerant circuit and refrig-
erant amount.
• Check stop valve.
13
8-time blink
2.5 seconds OFF
Compressor syn-
chronous
abnormality
The waveform of compressor current is distorted.
• Reconnect connector of
compressor.
• Refer to 12-5. "How to check
inverter/compressor".
14
10-time blink
2.5 seconds OFF
Outdoor fan motor
Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan startup.
• Refer to 12-5. "Check of outdoor
fan motor.
• Refer to 12-5. "Check of inverter
P.C. board.
15
12-time blink
2.5 seconds OFF
Each phase current
of compressor
Each phase current of compressor cannot be detected
normally.
• Refer to 12-5. "How to check
inverter/compressor".
16
13-time blink
2.5 seconds OFF
Bus-bar voltage (DC) Bus-bar voltage of inverter cannot be detected normally.
• It occurs with following case.
Instantaneous power voltage drop.
(Short time power failure) (
RW50
)
• Refer to 12-5. "Check of power
supply". (
RW50
)
• Refer to 12-5. "How to check
inverter/compressor".
17
Outdoor unit
operates.
1-time blink
2.5 seconds OFF
Frequency drop by
current protection
RW25/35
When the input current exceeds approximately
10A, compressor frequency lowers.
The unit is normal, but check the
following.
•
Check if indoor filters are clogged.
• Check if refrigerant is short.
• Check if indoor/outdoor unit air cir-
culation is short cycled.
RW50
Current from power outlet is nearing breaker
capacity.
18
3-time blink
2.5 seconds OFF
Frequency drop by
high pressure
protection
Temperature of indoor coil thermistor exceeds 55°C in HEAT
mode, compressor frequency lowers.
Frequency drop by
defrosting in COOL
mode
Indoor coil thermistor reads 8°C or less in COOL mode, com-
pressor frequency lowers.
19
4-time blink
2.5 seconds OFF
Frequency drop by
discharge tempera-
ture protection
Temperature of discharge temperature thermistor exceeds
111°C, compressor frequency lowers.
• Check refrigerant circuit and refrig-
erant amount.
• Refer to 12-5. "Check of LEV".
• Refer to 12-5. "Check of outdoor
thermistors".
OBH903
