How is the BDV test performed on a transformer?

The BDV test of a transformer is performed using a high-voltage insulation tester designed specifically for measuring breakdown voltage of insulating liquids. First, the oil sample is collected from the transformer and placed in a clean, appropriate-sized cup of the tester. The testing device applies a controlled voltage to the oil sample through electrodes, which are typically placed at a specific distance to ensure accurate measurements. The voltage is gradually increased until the oil breaks down and electrical discharge occurs. The BDV value is recorded at the point of breakdown, indicating the quality of the oil’s insulation properties. Regular BDV testing is essential for maintenance and helps prevent transformer failures by assessing the electrical integrity of the insulating oil.