A refrigeration circuit circulating a refrigerant and comprising in the direction of flow: at least one compressor of a first group of compressors; a heat rejecting heat exchanger ; an expansion device ; and an evaporator ; the refrigeration circuit further comprising: at least one compressor of a second group of compressors, wherein the suction pressure of the at least one compressor of the second group of compressors is larger than the suction pressure of the at least one compressor of the first group of compressors; an oil collector being selectively connectable to the at least one compressor of the first group of compressors and/or to the at least one compressor of the second group of compressors for collecting excess oil from the at least one compressor of the first group of compressors; wherein the oil collector is connected by a high-pressure line to a high pressure discharge line of the at least one compressor of the first group of compressors, and a switchable high pressure valve is arranged within said high-pressure line allowing to selectively increase the pressure within the oil collector by opening the high pressure valve and fluidly connecting the oil collector to the high pressure discharge line in order to transfer oil from the oil collector to the at least one compressor of the second group of compressors. at least one compressor of a first group of compressors; a heat rejecting heat exchanger ; an expansion device ; and an evaporator ; the refrigeration circuit further comprising: at least one compressor of a second group of compressors, wherein the suction pressure of the at least one compressor of the second group of compressors is larger than the suction pressure of the at least one compressor of the first group of compressors; an oil collector being selectively connectable to the at least one compressor of the first group of compressors and/or to the at least one compressor of the second group of compressors for collecting excess oil from the at least one compressor of the first group of compressors; wherein the oil collector is connected by a high-pressure line to a high pressure discharge line of the at least one compressor of the first group of compressors, and a switchable high pressure valve is arranged within said high-pressure line allowing to selectively increase the pressure within the oil collector by opening the high pressure valve and fluidly connecting the oil collector to the high pressure discharge line in order to transfer oil from the oil collector to the at least one compressor of the second group of compressors. at least one compressor of a second group of compressors, wherein the suction pressure of the at least one compressor of the second group of compressors is larger than the suction pressure of the at least one compressor of the first group of compressors; an oil collector being selectively connectable to the at least one compressor of the first group of compressors and/or to the at least one compressor of the second group of compressors for collecting excess oil from the at least one compressor of the first group of compressors; wherein the oil collector is connected by a high-pressure line to a high pressure discharge line of the at least one compressor of the first group of compressors, and a switchable high pressure valve is arranged within said high-pressure line allowing to selectively increase the pressure within the oil collector by opening the high pressure valve and fluidly connecting the oil collector to the high pressure discharge line in order to transfer oil from the oil collector to the at least one compressor of the second group of compressors. <EOS>