Patent ID: 8813511

Claim:
A refrigeration system comprising: a variable capacity compressor system configured to compress refrigerant; a condenser configured to receive and to condense the compressed refrigerant; an expansion device configured to expand the condensed refrigerant; an evaporator configured to evaporate the expanded refrigerant prior to returning the refrigerant to the variable capacity compressor system; one or more fans driven by a fan drive and configured to displace air over the condenser; a means for determining a discharge pressure of the variable capacity compressor system; and a controller operatively coupled to the fan drive and configured to: regulate the fan drive based on an operational capacity of the variable capacity compressor system when the discharge pressure is within a range defined by a first level and a second level, regulate the fan drive based on the discharge pressure when the discharge pressure is below the first level or above the second level, reduce fan speed of the fan drive based on the discharge pressure when the discharge pressure is below the first level, deactivate the variable capacity compressor system when the discharge pressure is below a third level, wherein the third level is below the first level, increase fan speed of the fan drive when the discharge pressure is above the second level, and interrupt operation of the variable capacity compressor system when the discharge pressure is above a fourth level, wherein the fourth level is above the second level.