Method and a control unit for starting a compressor

Abstract

A method and a control unit for starting a compressor ( 3 ) in a refrigeration system ( 1 ) further comprising a condenser ( 2 ) and an evaporator ( 4 ). If an attempt to start-up the compressor ( 3 ) is unsuccessful a condenser cooling means, e.g. a fan, is started in order to provide cooling for the condenser ( 2 ). Thereby, if the temperature of the condenser is sufficiently high to cause an increased pressure on the condenser side of the compressor ( 3 ), cooling is provided for the condenser ( 2 ) in order to ensure a reliable start-up of the compressor ( 3 ). On the other hand, if the temperature of the condenser ( 2 ) is sufficiently low to ensure a reliable start-up of the compressor ( 3 ), cooling is not provided, thereby saving power while ensuring reliable start-up of the compressor ( 3 ).

1 . A method for starting a compressor in a refrigeration system, the refrigeration system further comprising a condenser and an evaporator, said compressor, condenser and evaporator being interconnected in a circuit in which a refrigerant is allowed to flow, the method comprising the steps of: 
 attempting start-up of the compressor, thereby initiating a start-up sequence,    determining whether the attempted start-up of the compressor was successful,    in the case that it is determined that the attempted start-up of the compressor was unsuccessful, starting a condenser cooling means, thereby providing cooling for the condenser, and waiting for a predefined time interval,    repeating the above steps until it is determined that the attempted start-up of the compressor was successful, and    ending the start-up sequence.    
     
     
         2 . The method according to  claim 1 , wherein the predefined time is within the time interval 10 s to 300 s.  
     
     
         3 . The method according to  claim 1 , wherein the step of starting a condenser cooling means comprises supplying power to a fan positioned in the vicinity of the condenser, thereby causing the fan to rotate.  
     
     
         4 . The method according to  claim 1 , further comprising the step of stopping the condenser cooling means after the predefined time has elapsed.  
     
     
         5 . The method according to  claim 1 , further comprising the steps of monitoring a temperature in the vicinity of the condenser, and starting the condenser cooling means in case said temperature exceeds a threshold temperature.  
     
     
         6 . A control unit for controlling start-up of a compressor in a refrigeration system, the refrigeration system further comprising a condenser and an evaporator, said compressor, condenser and evaporator being interconnected in a circuit in which a refrigerant is allowed to flow, the control unit comprising means for starting a condenser cooling means in case it is determined that an attempted start-up of the compressor was unsuccessful.  
     
     
         7 . The control unit according to  claim 6 , wherein the condenser cooling means comprises a fan positioned in the vicinity of the condenser, and wherein the means for starting the condenser cooling means comprises means for supplying power to the fan, thereby causing it to rotate.  
     
     
         8 . The control unit according to  claim 6 , further comprising means for monitoring a temperature in the vicinity of the condenser, and wherein the means for starting the condenser cooling means is adapted to start the condenser cooling means in case said temperature exceeds a threshold temperature.  
     
     
         9 . A starter assembly for starting a compressor in a refrigeration system, the starter assembly comprising a control unit according to  claim 6 .  
     
     
         10 . The starter assembly according to  claim 9 , wherein the starter assembly and/or the compressor is/are powered by means of a battery.