Transformer Insulation includes, Transformer Oil in the Main Tank and Transformer Winding Insulation.

Transformer Oil:

Function:

It is a Mineral Insulating Oil/Liquid Dilectric which provides following Functions:

  1.  Provides Insulation Between Core, Winding and the tank.
  2. Provides Cooling
  3.  Its Hygroscopic nature is useful in absorbing moisture from the Winding Insulation. 

    Factors affecting deterioration:

    1.  Voltage transients due to Faults.
    2. Heat due to Overlapping/ improper Cooling.
    3. Filling/topping up operation.
    4. Chemical Reation
    5. Moisture due to leakages and breathing action.
    6. Dirt due to improper breathing action
    7. Ageing of Solid and Liquid Insulation
    8. Oxygen.

      Corrective Actions:

      1. Filteration/reconditioning.
      2. Reclamation
      3. Re-fining
      4. Replacement.

        Corona Fault results in :

        1. Hydrogen

          Transformer Oil:

          Function:

          It is a Solid Insulation of Cellulose material which provides following Functions:

          1. It prevents the shorting of the two windings.

            Factors affecting deterioration:

            1.  Cellulose degradation, which gives rise to gasses.
            2. Polymerisation of Cellulose.

              Corrective Actions:

              1. Rewinding

                Corona Fault results in :

                1. Hydrogen
                2. Carbon Momoxide
                3. Carbon Dioxide

                  Please note that same Switch is also availabe in Circuit Breaker for Local Closing and Tripping.