Why do we use mineral oil in transformers?
Transformer oil is a mineral based oil that is commonly used in transformers for its chemical properties and dielectric strength. This oil in your transformer acts as an insulator and a cooling agent. The acid will form sludge which settles on the windings of the transformer resulting in reduced heat dissipation.
What is the purpose of using oil in the transformer?
The oil surrounding the coils in a power transformer provide cooling, insulation and protection against corona and arcing. It is normally obtained by fractional distillation and subsequent treatment of crude petroleum. This is why this oil is also known as mineral insulating oil.
Why maintenance of transformer is required?
The regular checking and maintenance of transformer is also known as condition maintenance. Hence by proper condition maintenance, one can avoid emergency and breakdown maintenance. That is why technical personnel should mainly concentrate on condition maintenance.
How much oil does a transformer hold?
A 300kVA oil-filled transformer would contain 300 to 400 gallons of mineral oil. What is being used nowadays is type 2 mineral oil. If you want “high fire point” go with “Envirotemp” soy-based oil, then change the rating to KNAN.
Is transformer oil harmful?
The main constituent of transformer oil is polychlorinated biphenyl (PCB) which is responsible for producing toxicity in humans. Chronic exposure with PCB may cause some toxicity such as hepatotoxicity and neurotoxicity.
How often should transformer oil be changed?
Dissolve Gas Analysis of transformer oil should be done annually for 132kv transformer, once in 2 years for the transformer below 132kv transformer, and once in 2 years for the transformer above 132kv transformer.
What is tripping of a transformer from the main circuit required?
3. When tripping of the transformer from the main circuit is required? Explanations: For all other options removing transformer from the circuit is not necessary as alarms and consequent actions help to remove that fault.
What causes hydrogen in transformer oil?
Stray gassing of hydrogen refers to the generation of hydrogen under moderate temperatures in the transformer. The cause has been attributed to the refining process and the possible presence of certain incompatible materials in the transformer or additives in the oil. This causes some of the gas to dissolve in the oil.
How do you add nitrogen to a transformer?
Before placing a transformer in storage, make sure the insulating liquid is at its proper level, add dry nitrogen in the gas space until the pressure reaches 3 psi (20.7 kPa) and then seal the unit.
What is stray gassing in transformer oil?
Stray gassing (SG) of oil has been defined by CIGRE [3] as “the formation of gases in electrical insulating oils heated at relatively low temperatures of 90 to 200 ◦C”.
Which gas is used in transformer?
Gas is used as an insulating and cooling agent in gas insulated transformers. Sulphur hexafluoride (SF6) is the main gas used in these types of transformer at present although other gases are under development.
What is oil level indicator in transformer?
Our oil level indicators for transformers are used for hermetically sealed and for distribution transformers with expansion tank. The oil level indicator displays if air bubbles have remained in the transformer, if gas has been generated because of an internal failure or if there is a leakage at the transformer tank.