Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 1288:2000 is the Indian Standard (BIS) for methods of test for mineral insulating oils used in electrical equipment. IS 1288 is a multi-part standard providing test methods for transformer/insulating oil. The breakdown voltage (BDV) test is the most critical — it determines if the oil can safely insulate high voltage. Regular oil testing per IS 1288 is mandatory for transformer maintenance.
Methods of test for insulating oils used in transformers, switchgear, and other electrical equipment, covering breakdown voltage, acidity, moisture, sludge, and other properties.
Standard Test Methods for Dielectric Breakdown Voltage of Insulating Oils
Both provide BDV test methods for insulating oils. ASTM D877 uses disc electrodes; D1816 uses VDE electrodes.
IEC 60156:2018IEC
HighCurrent
Insulating liquids — Determination of the breakdown voltage at power frequency
IS 1288 BDV test is aligned with IEC 60156.
Key Differences
≠IS/IEC use 2.5mm gap. ASTM D877 uses 2.5mm (disc). ASTM D1816 uses 1mm and 2mm (VDE electrodes).
Key Similarities
≈All measure the voltage at which oil breaks down between standardized electrodes.
Parameter Comparison
Parameter
IS Value
International
Source
Electrode gap (standard)
2.5 mm
2.5 mm
IEC 60156
⚠ Verify details from original standards before use
Key Values4
Quick Reference Values
New oil BDV min30 kV (IS 335)
Service oil BDV min30 kV (acceptable)
Moisture max (new oil)50 ppm
Acidity max (service)0.5 mg KOH/g
Tables & Referenced Sections
Key Tables
No tables data
Frequently Asked Questions2
What is BDV test?+
Breakdown Voltage (BDV) test measures the voltage at which transformer oil breaks down (arcs) between two electrodes spaced 2.5mm apart. Minimum acceptable BDV for service oil is 30 kV. New oil should be >60 kV.
How often should transformer oil be tested?+
Annual testing for transformers >1000 kVA. Every 3 years for smaller. Additional testing after any fault, overload, or whenever oil temperature exceeds rated limits.