There are many equipment such as transformers, high voltage cables, insulators, breakers, etc. Experimental study on the dielectric breakdown voltage of. The bdv of oil in transformer is 60 kv1 min within the gap. Transformer oil, a type of insulating and cooling oil used in transformers and other electrical.
Each test is an indication of how suitable the insulation liquid is for service. Electrical breakdown testing of magnetic nanofluids found that for positive streamers. Transformer oil breakdown voltage testing procedure. To determine the insulating property of the dielectric oil, an oil sample is taken from the device under test, and its breakdown voltage is measured onsite in the vessel, two standardcompliant test electrodes with a typical clearance of 2. To assess the insulating property of dielectric transformer oil, a sample of the transformer oil is taken and its breakdown voltage is measured. Dielectric strength of transformer oil is also known as breakdown voltage of transformer oil or bdv of transformer oil. Connect the earth terminal on the right side of the equipment to the earth wire firmly before start the equipment.
Oil bdv tester transformer oil test kit oem manufacturer. The main aim of such a test is to examine the insulating property of the oil in a dielectric transformer. The dts series provides repeatable and accurate measurements of the breakdown voltage of insulating oils used in electrical equipment. Ots100af, ots80af and ots60af laboratory oil testers. As a result the breakdown voltage is calculated as mean value of the individual measurements. The test involves applying a ac voltage at a controlled rate to two electrodes immersed in the insulating fluid. The effect of moisture on the breakdown voltage of. Breakdown voltage of the transformer oils under certain. It is done for checking the dielectric strength of the oil of the transformer.
The approximatecompositions of niirabers1 to 6 inclusive fur. It is a measure of the ability of an oil to withstand electrical stress. A low breakdown voltage value can be a clear indication of contamination within the liquid from the degradation processes that occur during the lifetime of a transformer. It can be seen that the value of breakdown voltage spherical is higher than that of the mushroom electrode. Meggers automatic laboratory oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids. Break down voltage test of a 2 kv power transformer oil. The test voltage would be about 2 working voltage and the voltage is maintained from 15 min to 1. Jy6611 transformer oil breakdown voltage tester use advanced voltage breakdown control technology which will keep breakdown energy in a very low level,that will avoid pollution to oil sample during testing and make sure the test result are accurate and reliable. Break down voltage test of transformer oil duration. Various predefined and fully automatic test sequences meet all relevant international standards, thus the models of the ba series fulfill all legal requirements of the mandatory. In addition, aging of the transformer oil was simulated for. The lower the resulting breakdown voltage, the poorer the quality of the transformer oil.
There are many types of organisation that benefit from carrying out tests on transformer oil. Breakdown voltage of the transformer oils under certain conditions. However, it really depends on the application and again, the type of oil. Oil dielectric ac test sets provide replicable, accurate measurement of breakdown voltage of insulating oils used in electrical equipment. Dielectric breakdown the dielectric breakdown test is a physical test that measures the breakdown voltage of an insulation liquid. Who needs to perform dielectric breakdown voltage tests. Later in the experiments, we will focus mainly to examine the breakdown voltage.
The effect of moisture on the breakdown voltage of transformer oil. Testing consists of measuring breakdown voltage and other physical and chemical. It refers to the dielectric strength of transformer oil. Dielectric breakdown voltage and dielectric strength. The best way to test the breakdown voltage of transformer oil is to use a transformer oil test kit. A transformer oil breakdown test set is an equipment that measures the dielectric strength of the oil. Experimental study on breakdown characteristics of transformer. This paper has studied the breakdown voltages of transformer oil and. Dielectric breakdown voltage and dielectric strength date 1086 revision page2of3.
The breakdown voltage was the voltage that causes an electric arc which leads to a collapse of the test voltage. The main physical and chemical properties tested in transformer oil testing methods are the oil s dielectric strength, dissipation factor, flashpoint, color, amount of solid particulate matter, water content, gas content and the oil s acid number. The effect of moisture on the breakdown voltage of transformer oil materials and methods the transformer oil samples used in this study table 1 were three mineral oils, one synthetic esterbased oil, and two mineral oil samples taken from transformers in operation. Dielectric strength means the maximum capacity to withstand voltage of insulating oil. Breakdown voltage bdv in transformer oil powerlink oil. Determining the dielectric breakdown voltage of insulating liquids is important to understand the insulating liquids ability to withstand electric stress without failure. Bdv test is used to test or check the quality of transformer oil. Insulating oil in electrical power apparatus serves two primary roles, as an insulator and a coolant.
Due to the ultra fast voltage switchoff at flash over transformer oil testing of synthetic oil, ester oil and silicone oil is possible. The megger guide to insulating oil dielectric breakdown testing. Transformer oil or insulating oil is an oil that is stable at high temperatures and has excellent electrical insulating properties. After the transformer oil test is completed, the insulation oil is stirred automatically and the test sequence is performed repeatedly. Veer make oil bdv is specially designed for testing oil breakdown voltage. It is very often equated with breakdown voltage, but their numerical values are not equal. Hp transformer oil i is inhibited type transformer oil meeting is. Pdf breakdown voltage of the transformer oils under certain. If the breakdown voltage of the oil is on the lower side it means that it is of poor quality. These lightweight, rugged units are designed for field and laboratory use. For your application you might get away with 2030 kvmm. The megger guide to insulating oil dielectric breakdown.
The first test circuit was for generating impulse voltage with. Paper open access analysis of dielectric strength of. Breakdown voltage is a minimum voltage applied to an insulation, resulting in its breaking down and becoming electrically conductive. To test the oil sample, transformer oil is poured into a porcelain vessel in which two disk electrodes, one of 8mm diameter and one of 25mm diameter, are mounted. It is thus normal to subject the cable soon after laying it, but before energising it to carry out a high voltage test under d. In the dielectric strength test of transformer oil, the test voltage should be raised to the specified value or the breakdown voltage if it is less at a uniform rate in 1015 seconds and maintain for a one minute. No single test alone will represent or indicate the true condition of the liquid. It is fully automatic test kit developed to test oil sample as per is6792iec 60156 with printer facility. To determine dielectric strength, transformer oil is periodically tested by means of an oil punching apparatus. The test is performed with two or three consecutive samples of oil turn by turn. Breakdown voltage bdv testing of transformer oil youtube. Regular maintenance and upgrading of the oil will add years to the life of both your car and your transformer.
Transformer oil maintenance electric energy online. Transformer oil hp transformer oil i hp lubricants. Depending on the type of oil used the breakdown voltage can be up to 60kvmm dried oil or 40kvmm non driedoil. Breakdown voltage the breakdown voltage for all samples can be seen in table 3. How to test the breakdown voltage of the transformer oil. It is used in oil filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage switches and circuit breakers. Breakdown voltage value of insulating oil of the transformer.
The transparent, shielded lid and large test chamber enable easy access to the test vessel. The baur dta 100 c oil breakdown voltage tester fully automatically tests the electrical breakdown strength of insulating liquids. Its functions are to insulate, suppress corona discharge and arcing, and to serve as a coolant. Breakdown voltage is measured by observing at what voltage, sparking strands between two electrodes immersed in the oil, separated by a. It is commonly used in transformers because of its chemical properties and. What is the bdv value of distribution transformer oil. This test method is applicable to insulating liquids commonly used in cables, transformers, oil circuit breakers, and similar apparatus as an. The petroleum or mineral oil based transformer oil samples considered for this presentation are tested for various parameters following the procedure and guidelines as per is. The transformer oil testing device measures and reports the root mean square value of the breakdown voltage. These tests include dielectric breakdown, power factor, interfacial tension, acidity, and color. Moulded test vessels give repeatable results with lock in precision electrode gap setting adjustment wheels.
Break down voltage is measured by observing at what voltage, sparking straits between two electrodes emerged in the oil, separated by specific gap. When the current arcs across this gap the voltage recorded at that instant is the dielectric strength breakdown strength of the insulating liquid. The screen test is a collection of physical, electrical and chemical tests for the transformer oil. Through proper testing, the transformer s lifespan is increased, reducing the need to pay for replacement. Based on the test results, the oil can be identified as aged due to an increase in water content, sludge, or if the oil has oxidized. Inhibited transformer oils can extend the service life of transformer oil. Breakdown voltage testing of insulating oils can help to assess the condition of these oils within electrical equipment, such as transformers, capacitors, switches, etc.
Breakdown voltage is an important test for transformer oil. This test shows the dielectric strength of transformer oil. Oil quality transformer oil is a mineral based oil. Dielectric breakdown d1816 the dielectric breakdown is the minimum voltage at which electrical flashover occurs in an oil. The dielectric breakdown voltage test is a relatively quick and easy way of determining the amount of contamination in insulating oil. The transformer oil is filled in the vessel of the testing device. The transformer oil breakdown voltage test set supplied shall be preprogrammed atleast in accordance with the latest editions of the standard test methods specified in iec 60156 and amendments thereof. Transformer oil testing quick, simple and onsite b2hv.
Test sequences can be accomplished easily and fully automatically in compliance with all international and national standards. During the time of transformer operation, the oil will become degradation which may be the main cause for loss of function, decreasing the cooling capacity of the transformer, and etc. Oil tester breakdown analyzer ba60 ba75 ba80 ba100 b2hv. According iec standard, six measurements were carried out on the insulating oil. Transformer oil act as an insulating medium and also as a coolant that dissipates heat of the transformer. A larger quantity of oil is needed for these tests. Usually the contaminant is water, but it can also be conductive particles, dirt, debris, insulating particles and the byproducts of oxidation and aging of the oil. Oil in each instance degrades over time resulting in the potential for failure or costly repair bills. Transformer oil breakdown voltage tester or bdv tester is required to do breakdown voltage test and to check the dielectric strength of the oil of the transformer. The moisture level of the oil relative to saturation water activity in oil was determined using a vaisala mmt330 transmitter with the probe installed in the test cell of. Breakdown voltage characteristics of castor oil as. Pdf breakdown strength analysis of the transformer. Therefore, it is suggested that they all be performed. Break down voltage test of transformer oil youtube.
After breakdown occurred, the test voltage was automatically switched off. Oil testing consists of measuring the breakdown voltage, and other chemical and physical properties of the oil, either through portable test equipment or in a laboratory. Basic features the transformer oil tester shall be capable of measuring dielectric breakdown voltage of all. To gather the sample, a clean, moisture free container must be used typically a plastic. Which oil testing standard should you choose to determine. The insulation oils are used in such systems to provide the insulation and cooling respectively for high.
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