HITACHI RAC18CH1
Service Manual

! CAUTION
1. In quiet or stopping operation, slight flowing noise of refrigerant in the refrigerating cycle may be heard, this noise is normal for the operation. During Thunderstorms, it is recommended to stop the operation and to disconnect the power cord plug from the power outlet. The room air conditioner does not start automatically after recovery from power failure to prevent the fuse from blowing. Press the START/STOP button after 3 minutes after the unit has stopped. When the room air conditioner is stopped by the thermostat or after miss-operation, the cooling and heating operation may not start for 3 minutes. This is not abnormal and is the result of the operation of IC delay circuit. The IC delay circuit ensures that there is no danger of blowing fuse or damaging parts even if operation is restarted accidentally. This room air conditioner should not be used for cooling operation when the outside temperature is below 10°C (50°F). This room air conditioner (the reverse cycle) should not be used when the outside temperature is below �10°C (14°F). If the reverse cycle is used under this condition the outside heat exchanger may become frosted and efficiency will fall. When the outside heat exchanger is frosted, the frost is melted by operating the hot gas system. In this condition the fan will stop and the vapour may rise from the outside heat exchanger.

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