Losses Testing of Transformers is performed to measure the energy losses that occur during a transformer's operation. These losses are primarily categorized into no-load losses (core losses) and load losses (copper losses). No-load losses occur when the transformer is energized without load and are mainly due to magnetic hysteresis and eddy currents in the core. Load losses occur when the transformer is under load, caused by resistance in the windings. Accurate loss testing, conducted as per standards like IEC or IEEE, ensures the transformer operates efficiently, complies with energy regulations, and meets performance guarantees provided by the manufacturer.