MICROPROCESSOR CONTROLLED DEMAND DEFROST FOR A COOLED ENCLOSURE

摘要

A refrigerated device (10) having a cooled enclosure (12) and an evaporator (26) through which refrigerant is circulated. An air temperature sensor (44) adapted to generate an air temperature signal indicative of air temperature within the enclosure (12) is provided. A refrigerant temperature sensor (50) adapted to generate a refrigerant temperature signal indicative of refrigerant temperature is provided. A programmable controller (40) adapted to compare the air temperature signal and the refrigerant temperature signal to calculate a difference between the air temperature and the refrigerant temperature is provided. The controller (40) initiates a defrost routine for removing condensate from the evaporator (26) if the difference between the air temperature and the refrigerant temperature is greater or equal to a defrost threshold. Also disclosed are methods for defrosting a refrigerated device and for detecting condensate accumulation.