PSO transformer oil is pure mineral hydrocarbon oil, specially refined and blended with selected base oils having the properties of insulating coils of transformers, switches and circuit breakers both electrically and thermally. The oil is refined in such a way that it imparts exceptional high oxidation and high resistance to gas formation. The oil shows high degree of dielectric properties and resistance to power losses. Well-stabilized methods are used to control the quality of the oils in order to meet international specification standard and ensure maximum trouble free service.


  • A range of insulating cooling oil for Electrical Transformer, Oil Merged Switchgears, Circuit Breaker, Oil Filled Capacitors and Tap Chargers.


  • High dielectric strength maintains the efficiency of transformer.
  • Excellent thermal conductivity dissipates the operational heat of transformer’s components and keeps them cool to ensure extended service life.
  • Highly refined base oil with low temperature properties and controls deposit and sludge formation provide extended lubricant service life and maintain transformer efficiency.

Performance Standards

Meets or exceeds the following specifications:

IEC 60296-2012
BS 148/72

Typical Key Properties:

PSO Transformer Oil
Kinematic Viscosity @40°C,
2/s ISO 3104
12 max.
Kinematic Viscosity @-20°C,
2/s ISO 3104
1800 max.
Flash Point, (PMCC), °C,
min ISO 2719
Pour Point, °C ISO 3016 -30 max
Break Down Voltage,
Kv IEC 60156
30 min.
Acidity, mg KOH/gm,
IEC 62021-1
0.01 max.

These typical characteristics are of existing production, the future production will conform to PSO blending specifications hence any variation in these characteristics will not affect the product performance.