What Is Dielectric Breakdown Voltage?
BDV is the voltage at which insulating oil loses its dielectric strength and becomes conductive. It is measured by gradually increasing an AC voltage across a standard electrode gap immersed in the oil until a spark or breakdown occurs.
Our automated BDV testers use controlled voltage ramps and record the precise breakdown voltage (kV).
Test Standard
IEC 60156 – Insulating Liquids – Determination of the Breakdown Voltage at Power Frequency
Acceptable BDV Values (Guideline)
Test Method – IEC 60814
We use the Karl Fischer Coulometric Titration Method, the industry-standard approach defined in IEC 60814. This test accurately measures the water content in ppm (parts per million), detecting even trace levels of moisture in both new and in-service transformer oils.
Benefits of BDV Testing
- Detects Moisture Contamination
- Identifies Particulate Pollution
- Flags Oxidation and Sludge Formation
- Ensures Safe Operating Conditions
- Assesses Oil Filter Effectiveness
Our Testing Process
- Barcode-based sample collection in vacuum bottles
- On-site or laboratory BDV testing with calibrated test sets
- Real-time syncing to ERP and automatic interpretation
- Digital report generation with recommendations
Tru-FIL Advantages
NABL-accredited equipment & process
Fully automated BDV test benches
AI-powered ERP for instant analysis & alerts
24/7 operations for urgent testing needs
Pan-India sample collection & logistics support
Report Deliverables
- Breakdown Voltage (kV) per IEC 60156
- Number of breakdowns across test cycles (typically 5-6)
- Statistical average & standard deviation
- Test oil temperature & sample remarks
- Actionable insights and recommendations
| Oil Condition | Minimum BDV (kV) |
|---|---|
| New mineral oil | ≤ 60 kV |
| In-service oil | ≤ 40 kV |
| Alarm condition | ≤ 30 kV |