Air conditioner and method of controlling the same

Abstract

An air conditioner having a low-pressure switch and a power supply unit. The low-pressure switch shuts off the supply of power to an indoor unit if a refrigerant pressure in a suction side of a compressor is decreased. The power supply unit supplies power to the indoor unit of the air conditioner so that a heating operation is performed using an electric heater mounted in the outdoor unit even though the low-pressure switch is turned off. The power supply unit may supply power to the indoor unit if an outdoor air temperature is equal to or lower than a preset reference temperature.

What is claimed is:  
     
         1 . An air conditioner having an outdoor unit with an electric heater and an indoor unit with a compressor, comprising: 
 a low-pressure switch to shut off supply of power to said indoor unit when a refrigerant pressure in a suction side of said compressor is decreased to a level equal to or below a reference pressure; and    a power supply unit to supply power to said indoor unit of the air conditioner to perform a heating operation using said electric heater mounted in said outdoor unit when said low-pressure switch is turned off.    
     
     
         2 . The air conditioner according to  claim 1 , wherein said power supply unit supplies power to said indoor unit if an outdoor air temperature is equal to or lower than a preset reference temperature.  
     
     
         3 . The air conditioner according to  claim 2 , wherein said power supply unit comprises: 
 a relay connected in parallel to said low-pressure switch;    an outdoor air temperature detecting unit to detect an outdoor air temperature;    a control unit to output a relay drive signal to turn said relay on if the detected outdoor air temperature is equal to or lower than said preset reference temperature; and    a relay drive unit to turn on said relay according to the relay drive signal of said control unit.    
     
     
         4 . A method of controlling an air conditioner in which when a refrigerant pressure in a suction side of a compressor is decreased, a low-pressure switch provided in an outdoor unit is turned off to shut off power from an indoor unit, comprising: 
 determining whether a current operation mode of the air conditioner is a heating operation mode;    supplying power to an indoor unit when a low-pressure switch is turned off in the heating operation mode; and    performing the heating operation mode by operating an electric heater mounted in the indoor unit using the supplied power.    
     
     
         5 . The method according to  claim 4 , wherein said supplying of the power comprises: 
 detecting an outdoor air temperature in the heating operation mode;    determining whether the detected outdoor air temperature is equal to or lower than a reference temperature; and    supplying the power to the indoor unit by operating a relay connected in parallel to the low-pressure switch when the detected outdoor air temperature is equal to or lower than the reference temperature.    
     
     
         6 . An air conditioner having a compressor and a heating element, comprising: 
 a low-pressure switch terminating flow of power to said heating element upon detection of a predetermined decrease in refrigerant pressure in said compressor; and    a power supply unit bypassing said low-pressure switch, to provide the power to said heating element in a heating operation mode.    
     
     
         7 . An air conditioner having predetermined components, comprising: 
 a low-pressure switch terminating flow of power to said predetermined components in response to detection of a decrease in refrigerant pressure in said air conditioner; and    a power supply unit bypassing said low-pressure switch, to provide the power to said predetermined components in a corresponding operation mode.    
     
     
         8 . The air conditioner according to  claim 7 , wherein said power supply unit comprises: 
 a relay connected in parallel to said low-pressure switch;    an outdoor air temperature detecting unit to detect an outdoor air temperature;    a control unit to output a relay drive signal to turn said relay on if the detected outdoor air temperature is equal to or lower than said preset reference temperature; and    a relay drive unit to turn on said relay according to the relay drive signal of said control unit.