A method of operating a refrigeration system comprising: initiating a compressor shutdown operation; recording shutdown conditions at the time the compressor shutdown operation is initiated, wherein the shutdown conditions include at least one of return air temperature to an evaporator of the refrigeration system, supply air temperature to a volume cooled by the refrigeration system, or ambient air temperature; calculating one or more restart characteristics based on the recorded shutdown conditions, wherein the one or more calculated restart characteristics includes at least one of a calculated static pressure ratio and a predicted static saturated evaporator/suction temperature, wherein at least one of (i) the calculated static pressure ratio is a function of ambient air temperature and return air temperature to an evaporator of the refrigeration system and (ii) the predicted static saturated evaporator/suction temperature is based on a return air temperature at an evaporator of the refrigeration system; comparing the calculated restart characteristics with one or more compressor restart safety limits, wherein calculated restart characteristics is a calculated the static pressure ratio and the restart safety limits is a predetermined static pressure ratio limit, and the comparison comprises determining if the calculated static pressure ratio is less than the predetermined static pressure ratio limit; and/or wherein the calculated restart characteristics is a predicted static saturated evaporator/suction temperature and the restart safety limits is a predetermined static saturated evaporator/suction temperature limit, and the comparison comprises determining if the predicted static saturated evaporator/suction temperature is less than the predetermined static saturated evaporator/suction temperature limit; when the calculated restart characteristics do not satisfy the restart safety limits, controlling an electronic valve assembly to close while the compressor is running and performing a temperature modulation pump down operation to reduce a refrigerant density; and when the calculated restart characteristics satisfy the restart safety limits, completing the compressor shutdown operation. initiating a compressor shutdown operation; recording shutdown conditions at the time the compressor shutdown operation is initiated, wherein the shutdown conditions include at least one of return air temperature to an evaporator of the refrigeration system, supply air temperature to a volume cooled by the refrigeration system, or ambient air temperature; calculating one or more restart characteristics based on the recorded shutdown conditions, wherein the one or more calculated restart characteristics includes at least one of a calculated static pressure ratio and a predicted static saturated evaporator/suction temperature, wherein at least one of (i) the calculated static pressure ratio is a function of ambient air temperature and return air temperature to an evaporator of the refrigeration system and (ii) the predicted static saturated evaporator/suction temperature is based on a return air temperature at an evaporator of the refrigeration system; comparing the calculated restart characteristics with one or more compressor restart safety limits, wherein calculated restart characteristics is a calculated the static pressure ratio and the restart safety limits is a predetermined static pressure ratio limit, and the comparison comprises determining if the calculated static pressure ratio is less than the predetermined static pressure ratio limit; and/or wherein the calculated restart characteristics is a predicted static saturated evaporator/suction temperature and the restart safety limits is a predetermined static saturated evaporator/suction temperature limit, and the comparison comprises determining if the predicted static saturated evaporator/suction temperature is less than the predetermined static saturated evaporator/suction temperature limit; when the calculated restart characteristics do not satisfy the restart safety limits, controlling an electronic valve assembly to close while the compressor is running and performing a temperature modulation pump down operation to reduce a refrigerant density; and when the calculated restart characteristics satisfy the restart safety limits, completing the compressor shutdown operation.