A commercial refrigeration system has a control system which distributes intelligence to increase granularity of the control and simplify wiring, assembly and installation. Compressors of the refrigeration system each have a bus compatible compressor safety and control module including a processor and sensors. All control and safety modules communicate over a single power and communications line with the controller, providing digital transmissions to the controller of measurements taken by the sensors. The information provided may include that the compressor is outside of a specific safety parameter, so that the controller knows not only that a safety parameter has been traversed, but exactly which one. The control and safety modules are capable of executing commands from the controller to cycle the compressors. The control and safety modules preferably contain sufficient intelligence to continue system operation upon failure of the controller. A compressor is also disclosed which has an intelligent control and safety module. The compressor also houses control and safety devices within a hermetically or semi-hermetically sealed shell. A condenser controller is also disclosed that is capable of communicating with the controller to affect intelligent control of one or more compressor fans.