Transformer Oil


Also found in: Wikipedia.

transformer oil

[tranz′fȯr·mər ‚ȯil]
(materials)
A high-quality insulating oil in which windings of large power transformers are sometimes immersed to provide high dielectric strength, high insulation resistance, high flash point, freedom from moisture, and freedom from oxidization.

Transformer Oil

 

a petroleum or synthetic oil used as an insulator and coolant in transformers and other oil-filled electrical equipment. Petroleum transformer oils are also used in oil circuit breakers for extinguishing an electric arc when the current is switched off.

Most transformer oils are petroleum oils. They are obtained by refining the appropriate petroleum distillates with the aid of selective solvents (phenol or furfural), sulfuric acid, or adsorbents or by hydrogenation. The process of extracting oils from raw material containing paraffin hydrocarbons includes a dewaxing stage.

Transformer oils should have a high dielectric strength, a high

Figure 1. Impedance transformers: (a) coaxial and (b) wave-guide quarter-wave types with fixed resistance, (c) adjustable coaxial double-stub, (d) adjustable coaxial with dielectric bushings, (e) wave-guide type with double tee junction; (1) and (2) adjustable plungers, (3) and (4) movable dielectric bushings, (5) H-arm, (6) transformer input, (7) E-arm, (8) transformer output, (D) diameter of outer conductor of coaxial line, (d1), (d2), and (d) diameters of inner conductor of coaxial line from the generator side, from the load side, and in the transformer portion, respectively, (b1), (b2), and (b) dimensions of smaller side of cross section of rectangular wave guide from the generator side, from the load side, and in the transformer portion, respectively, (l) distance between centers of the dielectric bushings, (λ) effective wavelength in the line, (ε) dielectric constant. Dotted rectangles denote the location of movable plungers in the E- and H-arms of the tee junction.

resistivity, a small tangent of the dielectric loss angle, good resistance to oxidation, low viscosity, and low volatility. Petroleum transformer oils have a viscosity of 6–10 × 10–6 m2/sec at 50°C, a pour point not higher than –45°C, a flash point not lower than 135°C, a tangent of the dielectric loss angle not greater than 0.026–0.005 at 90°C, and a dielectric constant of 2.2–2.3; they should not contain water or any impurities. All grades of transformer oils produced in the USSR contain not less than 0.2 percent antioxidant additives, such as Ionol (2,6-di-tert-butyl-4-methylphenol).

The most widely used synthetic transformer oils are liquids based on chlorinated biphenyls and trichlorobenzene, for example, Geksol and Sovtols. Hydrocarbon, organosilicon, and organophosphorus synthetic oils are also used in certain types of special transformers.

REFERENCES

Lipshtein, R. A., and M. I. Shakhnovich. Transformatornoe maslo, 2nd ed. Moscow, 1968.
Tovarnye nefteprodukty, ikh svoistva i primenenie. Edited by N. G. Puchkov. Moscow, 1971.
Shakhnovich, M. I. Sinteticheskie zhidkosti dlia elektricheskikh apparatov. Moscow, 1972.

E. E. DOVGOPOLYI

References in periodicals archive ?
The project would increase the capacity of KLC to test samples of imported POL products from ships, inspection and collection of samples from all oil marketing companies' terminals and depots, refineries, lube oil blending plants, lube oil reclamation plants, grease and transformer oil plants.
[ClickPress, Fri Sep 25 2015] Transformer Oil Market by Type (Mineral- Naphthenic and Paraffinic), by Application (Small transformers, Large Transformers, Utility & Others), & Region (Asia-Pacific, North America, Europe, ROW) - Global Trends & Forecasts to 2020
Unifin's line of transformer oil pumps is manufactured under the company's Cardinal brand.
The project would increase the capacity of KLC to test samples of imported POL products from ships, inspect and collect samples from all oil marketing companies' terminals and depots, refineries, lube oil blending plants, lube oil reclamation plants, grease and transformer oil plants.
While, under the second project HDIP would upgrade its laboratories in Islamabad, Lahore, Multan, Peshawar, Quetta for testing locally producedand imported petroleum products like gasoline, diesel oils, furnace oil, transformer oil, lubricating oil and greases at a cost of Rs 434.47 million, the sources added.