11-3. TROUBLESHOOTING CHECK TABLE
No. Symptom LED
indication Abnormal point/
Condition
Condition Remedy
1
Outdoor unit
does not op-
erate.
1-time
fl
ash every
2.5 seconds
Outdoor power sys-
tem
Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started.
Reconnect connector of compres-
sor.
Refer to 11-5. "How to check in-
verter/compressor".
Check stop valve.
•
•
•
2
Outdoor thermistors Discharge temperature thermistor,
fi
n temperature thermistor,
defrost thermistor, P.C. board temperature thermistor, outdoor
heat exchanger temperature thermistor or ambient tempera-
ture thermistor shorts or opens during compressor running.
Refer to 11-5. "Check of outdoor
thermistors".
•
3
Outdoor control sys-
tem
Memory data cannot be read.
(The upper lamp of OPERATION INDICATOR lamp of the in-
door unit lights up or
fl
ashes 7-time.)
Replace inverter P.C. board.
•
4
6-time
fl
ash
2.5 seconds OFF
Serial communica-
tion
The communication fails between the indoor and outdoor unit
for 3 minutes.
Check connection between the
inverter P.C. board and relay P.C.
board.
Refer to 11-5. "How to check mis-
wiring and serial signal error.
•
•
5
11-time
fl
ash
2.5 seconds OFF
Stop valve/
Closed valve
Closed valve is detected.
Check stop valve.
•
6
16-time
fl
ash
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 11-5. "Check of R.V.
coil".
Replace inverter P.C. board.
•
•
7
'Outdoor unit
stops and
restarts 3
minutes later'
is repeated.
2-time
fl
ash
2.5 seconds OFF
Overcurrent protec-
tion
Large current
fl
ows into IGBT module (IC700).
Reconnect connector of compres-
sor.
Refer to 11-5. "How to check in-
verter/compressor".
Check stop valve.
•
•
•
8
3-time
fl
ash
2.5 seconds OFF
Discharge tempera-
ture overheat protec-
tion
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 11-5. "Check of LEV".
•
•
9
4-time
fl
ash
2.5 seconds OFF
Fin temperature
/P.C. board tem-
perature thermistor
overheat protection
Temperature of
fi
n temperature thermistor on the heat sink
exceeds 75 ~ 80°C or temperature of P.C. board temperature
thermistor on the inverter P.C.board exceeds 70 ~ 75°C.
Check around outdoor unit.
Check outdoor unit air passage.
Refer to 11-5. "Check of outdoor
fan motor".
•
•
•
10
5-time
fl
ash
2.5 seconds OFF
High pressure pro-
tection
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.
•
•
11
8-time
fl
ash
2.5 seconds OFF
Compressor syn-
chronous abnormal-
ity
Compressor current is abnormal.
Reconnect connector of compres-
sor.
Refer to 11-5. "How to check in-
verter/compressor".
•
•
12
10-time
fl
ash
2.5 seconds OFF
Outdoor fan motor
Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan start-up.
Refer to 11-5. "Check of outdoor
fan motor.
Refer to 11-5. "Check of inverter
P.C. board.
•
•
13
12-time
fl
ash
2.5 seconds OFF
Compressor current Compressor current cannot be detected normally.
Refer to 11-5. "How to check in-
verter/compressor".
•
14
13-time
fl
ash
2.5 seconds OFF
Bus-bar voltage
(DC)
Bus-bar voltage cannot be detected normally.
It occurs with following case.
Instantaneous power voltage drop.
(Short time power failure)
Refer to 11-5. "Check of power
supply".
Refer to 11-5. "How to check in-
verter/compressor".
•
•
•
15
Outdoor unit
operates.
1-time
fl
ash
2.5 seconds OFF
Frequency drop by
current protection
Current from power outlet is nearing breaker capacity.
The unit is normal, but check the
following.
Check if indoor
fi
lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air cir-
culation is short cycled.
•
•
•
16
3-time
fl
ash
2.5 seconds OFF
Frequency drop by
high pressure pro-
tection
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.
17
4-time
fl
ash
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 11-5. "Check of LEV".
Refer to 11-5. "Check of outdoor
thermistors".
•
•
•
18
7-time
fl
ash
2.5 seconds OFF
Low discharge tem-
perature protection
Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.
Refer to 11-5. "Check of LEV".
Check refrigerant circuit and refrig-
erant amount.
•
•
26
OBH635
