This document specifies the rating conditions, tolerances and the method of presenting performance data of refrigerant compressors to enable comparison of different compressors.This document is applicable to single-stage compressor and two-stage compressor data with or without an additional intermediate pressure inlet.The performance data of compressors used with R-744 in transcritical operation are covered in this document.The data relating to the refrigerating capacity, heating capacity and power absorbed include requirements for part-load operation where applicable.