DUAL PUMP DOWN CYCLE FOR PROTECTING A COMPRESSOR IN A REFRIGERATION SYSTEM

摘要

An expansion valve (11) is driven to a fully closed position to prevent refrigerant flow from the condenser to the evaporator whenever the refrigeration system is shut down. The refrigeration system compressor (12) is run for a preselected amount of time sufficient to reduce the refrigerant pressure in the evaporator to a desired level after the expansion valve is driven to its fully closed position by the step of driving. The compressor is then run for a second preselected amount of time sufficient to reduce the refrigerant pressure in the evaporator to a second desired level while maintaining the expansion valve in its fully closed position prior to the refrigeration system after a shut down.