Why is the BDV test essential for transformer oil condition assessment?

BDV testing provides a fast, practical measure of how well the oil can withstand an electric field without breakdown. A drop in BDV often correlates with moisture, particles, fibers, or other contamination that increases failure risk. While BDV does not identify the fault source by itself, it is a valuable screening tool to trigger filtration, dehydration, or deeper diagnostics. Using a consistent standard method and trending results over time is what makes it actionable.