THE IMPORTANCE OF DISSOLVED GAS ANALYSIS DURING FACTORY ACCEPTANCE TESTS

Dissolved gas analyses (DGA) of oil are routinely used as a standard quality control procedure during factory tests of power transformers. The factory acceptance tests (FAT) represent the final and critical step in ensuring quality before the transformer leaves the factory. This paper discusses the significance of dissolved gas analysis within the context of factory testing of transformers. Several cases demonstrating different oil analysis protocols applied to both, new and repaired transformers were presented. Recommendations are provided for enhancing the factory tests for overhauled transformers to verify the repairs conducted before they leave the factory and are put into operation.