This part of IEC 60034 applies to large rotating electrical machines and establishes additional methods of determining separate losses and to define an efficiency supplementing IEC 60034-2-1. These methods apply when full-load testing is not practical and result in a greater 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. Summation of losses for permanent magnet excited synchronous machines.