In extremely cold climates, specific gravity can be used to determine whether ice will float on the oil. For mineral oil, the power factor of new oil should not exceed 0.05 percent at 25 degrees C. Determines the density, relative density (specific gravity), or API gravity of transformer oil by use of hydrometer at a reference temperature. Contamination of the oil is exhibited by poor transparency, cloudiness, or the observation of foreign particles. 2. Transformer oil testing is one of the important parts of a power transformer. This test is particularly useful in cold climates to ensure that the oil will circulate and serve its purpose as an insulating and cooling medium. 4. This early warning system can allow maintenance management to identify maintenance priorities, plan work assignment schedules, arrange for outside service, and order necessary parts and materials. Over the past five decades we have generated millions of test results from thousands of high-voltage units, and we process samples from transformer owners across the country. Then use a magnet to remove the metal particle from the oil by putting is through the oil-testing cup. Expressed in mN/m, it is a test of interfacial tension of water against oil, which is different from surface tension in that the surface of the water is in contact with oil instead of air. Now the testing oil sample is in good condition then it should withstand 25 KW for one minute in a standard oil testing cup with a 2.5 mm gap between electrodes. 1. In a used oil it measures the amount remaining after oxidation has reduced its concentration. If the oil condition is good then it should withstand 45 kV for one minute in a standard oil testing cup with a 4 mm gap between electrodes. An oil sample tube and syringe is used to draw, retain and transport the oil sample in the … Noticeable darkening oil indicates either contamination or that arcing is taking place. A low resistivity reflects a high content of free ions and ion-forming particles in the insulating oil, and normally indicates a high concentration of conductive contaminates. In the last five decades in India, there is a drastic change in production technology. 2. In this post, I will explain everything about this experiment and I will also provide you a live video link that you can understand very well. Then fill up the sample oil in the testing-cup at 90% by removing its cover. Measurements are made using high-performance liquid chromatography (HPLC). Acidity below at 0.5 mg KOH/gm is permissible if the oil is satisfactory. Analytical Testing. Transformer Working Principle, Construction and Types, Current Transformer – Need, Working, Types, and Losses, What is Transformer Oil and Types of Transformer Oil, Transformer Installation, Inspection and Commissioning, Transformer Schedule and Overhaul Maintenance. Measures the voltage at which the oil fails electrically, which is indicative of the amount of contaminant (usually moisture) in the oil. This acid is responsible for corrosive in nature and damages the winding core, main body tanks, and other components. This test will be performed when your power ... Current Transformers (CT) are the devices in which the secondary current used for calculation is proportional to the primary current produced ... Power Transformer is always an essential part of an electrical substation. Measured in ppm, it also applies to the determination of PCB present in mixtures known as askarels. You have to remember one thing; the testing voltage of the transformer oil tester should be increased gradually. In this post, I will discuss the schedule and overhaul maintenance for a power transformer. The mineral-based oil like transformer oil is frequently used in different types of transformers for its dielectric strength as well as electrical properties. First of all, you have to collect the oil sample from an active transformer. This formation is rapid at temperature is above 750c. SDMyers has developed test packages to identify virtually any transformer oil issue. You have to remember one thing; the testing voltage of the. Regular sampling and testing of insulation oil taken from transformers is a valuable technique in a preventative maintenance pr ogram. This paper reviews some of the transformer oil tests and there significance. 2. Oil is visually examined by passing a beam of light through it to determine transparency and identify foreign matters. 2. You can quickly and accurately identify the condition of your oil’s relative density, dielectric breakdown voltage, dissolved gas content, oxidation inhibitor levels and more. Then use a magnet to remove the metal particle from the oil by putting is through the oil-testing cup. It is also responsible for sludge formation. Useful for measuring changes within the insulating oil resulting from contamination or deterioration. Now for testing of the transformer oil has two methods. Different gasses will dissolve in the oil that indicate various types of thermal and electrical stress occurring within the transformer. Its use to call transformer oil and it a little bit pricey. Because all impurity and dusty oil always stay at the bottom level. Transformer oil testing is one of the important parts of a power transformer.This test will be performed when your power transformer cooling system is an oil type. Oil color is determined by means of transmitted light and given a numerical value (0-5) based on comparison with a series of color standards. Acidity above 1 mg/gm means oil discard. If you are an electrical engineer then you will responsible for taking care of a power transformer in your workplace. But you have to remember one thing that you have to collect the down level of oil. Please try again later. There was an error trying to add your email address to the mailing list. Acidity between 0.5 to 1.00 mg keeps the oil under observation. SDMyers has the largest transformer oil testing lab in the world, with packages that test for every known fault condition. Transformer oil is not any ordinary oil. Used to observe darkening of the oil by comparing it to previous samples of oil from the same transformer. Measured by inductively coupled plasma atmonic emission spectrometry (ICP-AES) and expressed in micrometers. Determines the presence of degradation in cellulosic materials such as paper, pressboard, and cotton, which generate furanic compounds in the insulating oil. Now covered the cup and run the test three times. 3. Acidity above 1 mg/gm means oil discard. You can take any method that I mentioned according to your oil sample condition. References: Transformer Oil Sampling – NETA World Summer 2009, ASTM International, Wikipedia, Analyzing transformer insulating fluid - EC&M. It’s your responsibility to keep this active 24/7. Indicates the dielectric losses of the oil, or energy that is dissipated as heat. 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