POWER lamp flashes
The thermistors in the outdoor unit are abnormal.
G Check of outdoor thermistors
Disconnect the connector of thermistor in the outdoor P.C. board (see below table), and measure the resistance of thermistor.
Is the thermistor normal? (Refer to |
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No | |||
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Replace the thermistor except RT64. When RT64 is abnormal, replace the inverter P.C. board.
Reconnect the connector of thermistor.
Turn ON the power supply and press EMERGENCY OPERATION switch.
Does the unit operate for 10 minutes or more |
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without showing thermistor abnormality? |
| No |
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| Yes |
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| OK. |
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Thermistor | Symbol |
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Defrost | RT61 | Between CN641 pin1 and pin2 |
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Discharge temperature | RT62 | Between CN641 pin3 and pin4 | Inverter P.C. board | ||||||||
Fin temperature | RT64 | Between CN642 pin1 and pin2 | |||||||||
Ambient temperature | RT65 | Between CN643 pin1 and pin2 |
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Outdoor heat exchanger temperature | RT68 | Between CN644 pin1 and pin3 |
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H Check of R.V. coil
First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to
In case CN721 is not connected or R.V. coil is open, voltage is generated between the terminal pins of the connector although any signal is not being transmitted to R.V. coil.
Check if CN721 is connected.
Unit operates COOL mode even if it is set to HEAT mode.
Disconnect connector (CN61) between the compressor and the intelligent power module.
Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode).
Is there 230 VAC between CN721
and 
on the inverter P.C. board 3 minutes after the power supply is turned ON?
Yes
Replace the
Replace the inverter No P.C. board.
Unit operates HEAT mode even if it is set to COOL mode.
Disconnect connector (CN61) between the compressor and the intelligent power module.
Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode).
Is there 230 VAC between CN721
and 
on the inverter P.C. board 3 minutes after the power supply is turned ON?
No
Replace the
Replace the inverter Yes P.C. board.
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