Refrigeration control

A system, comprising:

• an evaporator;
• a pulse-width modulated (PWM) variable capacity compressor coupled in fluid communication with said evaporator and including a first check valve located at an outlet thereof for prohibiting reverse migration of vapor refrigerant therethrough;
• a condenser coupled in fluid communication with said compressor and said evaporator;
• an expansion valve disposed intermediate said condenser and said evaporator;
• and
• an isolation valve disposed intermediate said condenser and said expansion valve, said isolation valve being in electrical communication with said PWM compressor and operable to respectively synchronize opening and closing of said isolation valve with on- and off-cycles of said PWM compressor, wherein said isolation valve prohibits off-cycle migration of liquid refrigerant.

A refrigeration system, comprising:

• an evaporator;
• a pulse-width modulated (PWM) variable capacity compressor coupled in fluid communication with said evaporator;
• a condenser coupled in fluid communication with said PWM compressor and said evaporator;
• an expansion valve disposed intermediate said condenser and said evaporator;
• an isolation valve disposed intermediate said condenser and said expansion valve, and in fluid communication with said PWM compressor;
• and
• a controller controlling said isolation valve to respectively synchronize opening and closing of said isolation valve with on- and off-cycles of said PWM compressor, wherein said isolation valve prohibits migration of liquid refrigerant to said evaporator during said off-cycle.