A method of distributing a refrigerant charge level in a refrigerant vapor compression system configured to use CO 2 refrigerant, the refrigerant vapor compression system having a refrigerant circuit including a refrigerant compression device , a refrigerant heat rejection heat exchanger downstream of said compression device, the heat rejection heat exchanger being configured to operate in a transcritical mode, a refrigerant heat absorption heat exchanger downstream of said refrigerant heat rejection heat exchanger, the heat absorption heat exchanger being configured to operate in a subcritical mode, and a primary expansion device disposed in the refrigerant circuit downstream of said refrigerant heat rejection heat exchanger and upstream of said refrigerant heat absorption heat exchanger, said method comprising: restarting the refrigerant compression device in a first mode; operating the primary expansion device independent of refrigerant heat absorption heat exchanger superheat; sensing pressure at a refrigerant reservoir using a sensor; comparing a supercritical condition of the refrigerant in the refrigerant reservoir to a prescribed condition; wherein when the supercritical condition is above the prescribed condition, operating a refrigerant flow device to controllably migrate refrigerant from the refrigerant reservoir to an inlet of the refrigerant compression device; operating an economizer solenoid valve in a refrigerant vapor line coupled to an intermediate port of the refrigerant compression device; opening an unload valve in a bypass line between the intermediate port and an inlet port of the refrigerant compression device when the supercritical condition is above the prescribed condition; pulsing the refrigerant flow device in a liquid injection line between the refrigerant reservoir and the inlet port of the refrigerant compression device when the supercritical condition is above the prescribed condition; wherein when the supercritical condition is below the prescribed condition for a prescribed interval, operating the primary expansion device to control the refrigerant heat absorption heat exchanger superheat; and transitioning the refrigerant vapor compression system to a second mode. restarting the refrigerant compression device in a first mode; operating the primary expansion device independent of refrigerant heat absorption heat exchanger superheat; sensing pressure at a refrigerant reservoir using a sensor; comparing a supercritical condition of the refrigerant in the refrigerant reservoir to a prescribed condition; wherein when the supercritical condition is above the prescribed condition, operating a refrigerant flow device to controllably migrate refrigerant from the refrigerant reservoir to an inlet of the refrigerant compression device; operating an economizer solenoid valve in a refrigerant vapor line coupled to an intermediate port of the refrigerant compression device; opening an unload valve in a bypass line between the intermediate port and an inlet port of the refrigerant compression device when the supercritical condition is above the prescribed condition; pulsing the refrigerant flow device in a liquid injection line between the refrigerant reservoir and the inlet port of the refrigerant compression device when the supercritical condition is above the prescribed condition; wherein when the supercritical condition is below the prescribed condition for a prescribed interval, operating the primary expansion device to control the refrigerant heat absorption heat exchanger superheat; and transitioning the refrigerant vapor compression system to a second mode. <EOS>