IS 335 Transformer Oil
IS 335 is the Indian Standard covering unused mineral insulating oil used in transformers and switchgear. Transformer oil provides electrical insulation, cooling, and reliable operation of electrical equipment.
Main Properties of Transformer Oil
Viscosity Lower viscosity supports better oil circulation and heat transfer.
Pour Point Indicates the lowest temperature at which the oil remains capable of flowing under specified conditions.
Breakdown Voltage BDV Indicates the dielectric strength of the oil and its ability to withstand electrical stress.
Dielectric Dissipation Factor DDF Indicates dielectric losses in the oil. A lower value generally indicates better insulating quality.
Appearance Good quality oil should be clear, transparent, and free from visible contamination.
Acidity Indicates acidic compounds that can develop due to oil oxidation and ageing.
Interfacial Tension IFT Helps assess contamination and deterioration caused by ageing and oxidation.
Flash Point Indicates fire safety by identifying the temperature at which oil vapour can ignite momentarily.
PCA Polycyclic aromatic compounds are controlled to address health and environmental considerations.
Maintaining proper transformer oil quality helps provide reliable insulation, effective cooling, and longer transformer service life.