Losses testing of transformers is a critical procedure used to measure the efficiency and performance of a transformer by identifying energy losses during operation. The two main types of losses tested are no-load losses (core losses) and load losses (copper losses). No-load losses occur when the transformer is energized without load, while load losses happen under full load conditions due to winding resistance. Accurate losses testing helps in evaluating the energy efficiency and cost-effectiveness of the transformer. This test is essential during manufacturing, commissioning, or maintenance to ensure compliance with industry standards and to optimize performance in real-world applications.