what is insulation resistance test of transformer?

The insulation resistance test of a transformer is a diagnostic procedure used to evaluate the integrity of the insulation material within the transformer. This test measures the resistance of the insulation to electrical current, typically using a megohmmeter. A high insulation resistance value indicates good insulation condition, while low values may suggest deterioration or moisture ingress, which can lead to potential failures. Regular testing helps ensure the transformer’s reliability and safety in operation.