IVT Nordic Inverter KHR-N Service Manual Del2.pdf

1. Self-Diagnosis Function: Hold emergency operation button for 5 seconds when indoor unit is not operating to call out self-diagnosis memory content.
2. Display Mode:
- Indoor unit: Seven-segment display section shows error main category and sub-category alternately.
- Outdoor unit: LED1 flashes according to self-diagnosis content, active for 3-10 minutes after self-diagnosis.
3. Malfunction Numbers and Remedies:
- 1-0: Outdoor unit thermistor short-circuit, check and replace thermistor assembly.
- 1-1: Outside temperature thermistor short-circuit, check lead wire and replace thermistor assembly.
- 1-2: Suction thermistor short-circuit, replace outdoor unit control PWB assembly.
- 1-3: 2-way valve thermistor short-circuit, replace outdoor unit control PWB assembly.
- 2-0: Compressor high-temperature error, check air outlet, power supply voltage, pipe connections, and replace compressor thermistor assembly.
- 2-1 to 2-4: Temporary stops due to overheat or freeze, no remedy specified.
- 3-0: Dry operation, temporary stop due to dehumidifying operation, no remedy specified.
- 5-0: Outdoor unit thermistor open-circuit, check connector and replace thermistor assembly.
- 5-1 to 5-4: Open-circuit errors, check and replace thermistor assembly or outdoor unit control PWB assembly.
- 6-0: Outdoor unit DC over current error, check IPM, heat sink, and fan motor, replace control PWB assembly or compressor.
- 6-1: IPM pin level error, check IPM attachment and replace control PWB assembly.
- 7-0: Outdoor unit AC over current error, check air outlet and fan motor.
- 7-1 to 7-3: AC over current errors, check IPM, air outlet, fan motor, and refrigerant volume, replace control PWB assembly or charge refrigerant.