This part of IEC 60034 applies to large rotating electrical machines and establishes additionalmethods of determining separate losses and to define an efficiency supplementingIEC 60034-2-1. These methods apply when full-load testing is not practical and result in agreater uncertainty.NOTE In situ testing according to the calorimetric method for full-load conditions is recognized.The specific methods described are:– Calibrated-machine method.– Retardation method.– Calorimetric method.