The Paragon line of twin-screw compressors includes models for air- and water-cooled condensing operation. Features include patented rotor profile geometry; automatic unloaded starting and continuous unloading down to 25 percent, with built-in Vi compensation at partial loads; and dependable rolling element bearing design with sealed cavity for reduced loads. High efficiency, patented rotor profiles and optimized housing geometry provide efficiency and reliability. The compressors are offered in 35 to 300 ton sizes for R134A, R507A, R407A and R404A. The Paragon control module is preloaded with software that simplifies the application by incorporating all slide valve control and compressor-protection algorithms into the module. The module functions to control compressor capacity by operating the compressor unloading slide valve as directed by a pressure transducer or NTC temperature sensor input (control variable) to the PCM.