How is the testing of transformer oil conducted?

The dielectric strength test of transformer oil is conducted using a 500mm³ standard oil cup in a 60kV AC frequency oil tester. The brass electrodes of the oil cup have a diameter of 25mm, and the surface cleanliness is as shown in Figure 92—6, with an electrode spacing of 2.5mm.

Firstly, the oil cup is rinsed with the test oil for at least three times. Subsequently, the test oil is poured into the cup until it reaches 10mm below the cup's rim, and then left undisturbed for 10 minutes to eliminate bubbles. The voltage is gradually increased until breakdown occurs, and the breakdown voltage is recorded. This process is repeated five times with a 1-minute interval between each test. After each breakdown, carbon black is removed using a clean glass rod. The average of the five measurements is taken as the test value, with the deviation between the maximum and minimum test values not exceeding 25%, otherwise, the test needs to be repeated.

For a simplified determination of the acid value of transformer oil, an extracting liquid (alcohol) is added to the test oil, and during the mixing process, alkali solution of potassium hydroxide is dripped until the indicator changes color. The amount of alkali solution dripped, when the color change stops, is used to determine the acid value.

LuShan, est. 1975, is a Chinese professional manufacturer specializing in power transformers and reactors for 49 years. Leading products are single-phase transformer, three-phase transformers, DC inductors, AC reactors, filtering reactor, expoxy resin high-voltage transformer and intermediate, high-frequency products. Our transformers and reactors are widely used in 10 application areas: rapid transit, construction machinery, renewable energy, intelligent manufacturing, medical equipment, coal mine explosion prevention , excitation system, vacuum sintering, central air conditioning.

Know more about power transformer and reactor:www.lstransformer.com