1. A multiple compressor refrigeration system arrangement comprising, a first hermetic shell compressor intended to be always running when the system is operating, a second hermetic shell compressor that may be cycled on and off when the system is running, a first suction gas conduit adapted to be connected to the suction line of the system and extending into the upper portion of the shell of said first compressor, a second suction line extending from within the upper portion oF said first compressor shell to within the upper portion of said second compressor shell, a first high pressure discharge line extending from said first compressor and connected in parallel to a second high pressure discharge line extending from said second compressor and adapted to be connected to the high pressure line of said system, and an oil equalizing conduit, connected between the shells of said first and second compressors and connected to open into said first compressor at the height of minimum desired oil level to be maintained in said first compressor when said first and second compressors are both running with normal oil supply in the system and connected to open in said second compressor at substantially the same height.