Controlling method for clothes dryer

1. A controlling method for a dryer, wherein at least one of a heat pump system or a heater is selected as a heat source for heating air supplied in to a drum and a heat supply capacity of the heat pump system is more than a heat supply capacity of the heater, the method comprising:

selecting both the heat pump system and the heater as the heat sources;

turning the heat pump system on

turning the heater on after the heat pump system is normally turned on;

turning the heater off to cool the drum and terminate drying after the drying is performed;

turning the heat pump system off after the heater is turned off; and

running the drum by driving a drive motor, wherein the running of the drum is started after performing a reverse rotation and a forward rotation of the drive motor in a sequential manner, and wherein the turning on of the heat pump system is started after performing a forward rotation of the drive motor.

2. The method of claim 1 , further including determining whether or not a compressor included in the heat pump system normally operates, wherein the turning on of the heater is performed after the normal, operation of the heat pump system is checked.

3. The method of claim 2 , wherein the determining of whether or not the compressor normally operates is performed by comparing a temperature variation of a refrigerant having passed through the compressor with a preset reference temperature variation.

4. The method of claim 2 , wherein the determining of whether or not the compressor normally operates includes:

measuring a temperature of a refrigerant discharged from the compressor;

measuring a temperature ot a refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor; and

determining whether or not the compressor normally operates according to a difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor.

5. The method of claim 4 , wherein it is determined that the compressor normally operates when the difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor is more than a predetermined value.

6. The method of claim 4 , further including turning the compressor off when the difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor is lower than the predetermined value, and displaying an existence of error in the dryer.

7. The method of claim 2 . the determining of whether or not the compressor normally operates is performed by measuring a discharge pressure of the compressor.

8. A controlling method for a dryer, wherein at least one of a heat pump system or a heater is selected as a heat source for heating air supplied in to a drum and a heat supply capacity of the heat pump system is more than a heat supply capacity of the heater, the method comprising:

selecting both the heat pump system and the heater as the heat sources;

turning the heat pump system on;

turning the heater on after the heat pump system is normally turned on;

turning the hearer off to cool the drum and terminate drying after the drying is performed;

turning the heat pump system off after the heater is turned off; and

determining whether or not a compressor included in the heat pump system normally operates, wherein the turning on of the heater is performed after the normal operation of the heat pump system is checked, wherein the determining of whether or not the compressor normally operates includes:

measuring a temperature of a refrigerant discharged from the compressor;

measuring a temperature of a refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor; and

determining whether or not the compressor normally operates according to a difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor.

9. The method of claim 8 , wherein it is determined that the compressor normally operates when the difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor is more than a predetermined value.

10. The method of claim 8 , further including turning the compressor off when the difference value between the temperature of the refrigerant discharged from the compressor and the temperature of the refrigerant discharged from the compressor after a preset time elapses from the measurement of the temperature of the refrigerant discharged from the compressor is lower than the predetermined value, and displaying an existence of error in the dryer.