What type of oil is used in transformers?

Mineral oil and Synthetic oil are the majorly used transformer oil. These are the petroleum products, like Naphthenic based transformer oil and Paraffinic based transformer oil. Naphthenic based transformer oils are known for their heat distribution, which is one of the main problems with transformer.

Which oil is best for transformer?

Naphthenic mineral oil
Naphthenic mineral oil has long been the most preferred insulating liquid for power transformer insulation because it has a good pouring point at low temperatures, good thermal cooling capacity, low cost, high efficiency and availability on the transformers market [1, 2, 3, 7].

What should be the BDV of transformer oil?

That means at which voltage dielectric strength of transformer oil between the electrodes has been broken down. A typical value of BDV Test result for 220 / 6.6 kV Transformer oil is 65 kV and moisture content should be less than 10 ppm.

What are the components of transformer oil?

Transformer mineral oil contains a mixture of different hydrocarbons but is generally composed of three main components: alkanes, cycloalkanes and aromatic hydrocarbons.

Why oil is used in a transformer?

Transformer oil is used to insulate high-voltage electrical infrastructure such as transformers, capacitors, switches and circuit breakers. Transformer oils are designed to operate effectively at very high temperatures, cooling, insulating, and stopping corona discharges and arcing.

What is type II transformer oil?

SUNOCO TYPE II TRANSFORMER OIL is an electrical insulating naphthenic oil that meets the ASTM D-3487 specification for inhibited oils.

What is ppm in transformer oil?

PPM stands for Parts Per Million. It is used to measure the weight of moisture divided by the value of oil. The moisture content in oil lowers the insulating system dielectric strength that permits flashover to harm a transformer. For example, for mineral oil, a generally accepted maximum moisture content is 35 ppm.

What is the viscosity of transformer oil?

High quality transformer oils are normally in the range of 7- 8 mm2/sec at 40°C and even with such low viscosity, they still meet the requirement for flash point (<135°C) from the same standard.

Is specification of transformer oil?

The leading transformer standard specifications are IEC 60296 and ASTM D 3487. The requirements in the standards are defined with minimum and maximum limits. The understanding of transformer oil qualities is important when deciding which oil is best for your equipment in order to get potential long in-service life.

Is 335 a transformer oil?

This standard, first published in 1953, was based on BS 148 : 1951 ‘Insulating oil for transformers and switchgear’, issued by the British Standards Institution. Separate standard, IS 12463 : 1988 ‘Specification for inhibited mineral insulating oils’ has since been brought out for inhibited mineral insulating oils.

Is transformer oil the same as mineral oil?

Mineral oil is generally effective as a transformer oil, but it has some disadvantages, one of which is its relatively low flashpoint versus some alternatives. Mineral oil is also an environmental contaminant, and its insulating properties are rapidly degraded by even small amounts of water.

What is Type 2 transformer oil?

What causes sludge to form in a transformer?

The impurities are in the form of semi-solid in a transformer oil. Sludge formation in the transformer is due to the oxidation reaction, damage of sludge insulation, decomposition if oil and insulation in transformer oil. Increasing of moisture in transformer oil can form sludge due to the reason of reducing the dielectric strength and corrosion.

How does oxidization of oil affect a transformer?

Oxidization is acid that forms in the oil when it comes in contact with oxygen. The acid will form sludge which settles on the windings of the transformer resulting in reduced heat dissipation. The windings will run hotter thereby creating more sludge which in turn will create even more heat.

What happens to oil in electric transformer when left untreated?

The windings will run hotter thereby creating more sludge which in turn will create even more heat. The high acid content and increased temperatures will accelerate the deterioration of the insulating qualities of the oil and if left untreated will cause the transformer to fail.

What do you need to know about transformer oil conditioning?

Transformer oil conditioning is a stream line oil filtration process of sludge purification, moisture removal and gas removal. The first step in this serial process is to raise the oil temperature to a desired level, generally upto 65 Deg C.