Oil testing of transformer pdf

Obtaining max operational life is vital dielectric fluid testing is primary diagnostic tool used to determine transformer condition. Transformer oil testing is a proven loss prevention technique that should be a part of any condition based predictive maintenance program. Though the life of a transformer is generally accepted to be 25 to 30 years, at tata power about 40 % of our transformers are in service for more than 25 years because of the elaborate condition monitoring process. Our 50 years of experience in transformer oil analysis guarantees precise and accurate analytical results. The automatically generated report of the transformer oil testing sequence is available as a pdf version and is stored to the internal memory. Testing your transformers on a regular basis will allow you to detect any unforeseen changes in the condition of your transformers. It evolved from the simple gonogo verdict into a sophisticated segment within transformer manufacturing.

Over 1,000,000 natural ester fluidfilled transformers in service globally. Jan 23, 2017 for the love of physics walter lewin may 16, 2011 duration. Oil analysis testing labs analyze a wide range of oil based products. While the generic term oil is almost universally used to describe insulating fluids, there are currently five different. Natural ester generates ethane under normal operation test limit is 400ppm therefore the current value is within acceptable limits. Transformer oil also known as insulating oil is a special type of oil which has excellent electrical insulating properties and is stable at high temperatures. Furan analysis and of testing of transformer oil powerlink. Most of the electric power utilities adopt regular analysis of insulating oil samples as a basic requirement of transformer maintenance program. In this book we have laid down important aspects on transformer testing in order to enhance the understanding of the testing procedures and its outcome.

The results from the testing are summarized in table 4. Transformer oil is used in oilfilled electrical power transformers to insulate, stop arcing and corona discharge, and to dissipate the heat of the transformer i. Transformer oil testing quick, simple and onsite b2hv. Assessing remnant life of transformer based on furan. Transformer oil, a type of insulating and cooling oil used in transformers and other electrical.

This means that a transformer can be classified as nonpcb with greater than 99% confidence. Testing has shown that the causes for generation of various gases are the same, whether the fluid in question is conventional transformer oil or beta fluid. In this article, we will examine the value and benefits of each test. Bluetooth connection as means of communication with the instruments a usb flash drive interface and a bluetooth connection is offered. The sub 2 transformer is filled with natural ester fr3 it appears there is elevated ethane however, the limits indicated are for mineral oil only. This is the critical acid number and deterioration increases rapidly once this level is exceed. This guide is classified into the following categories. For the purpose of bdv test, oil sample from transformer is taken in a sample bottle. Testing consists of measuring breakdown voltage and. Transformer precommissioning tests and afterreceipt checks you. During the transformer operation for a period, insulation oils will become dirty degradation which results in loosing function of the oil in transformer as insulation and cooling, in that case. Astm d117 18 standard guide for sampling, test methods.

New oil should have a minimum dielectric strength of 35 kv by astm methods of testing. Routine testing of transformer oils and insulating oils on a regular schedule is an accepted industry. The megger guide to insulating oil dielectric breakdown testing. The transformer oil testing device measures and reports the root mean square value of the breakdown voltage. The ac hv test value should not surpass 75% of the factory test value. When ac hipot tests are used for routine maintenance, the power transformer can be examined at rated voltage for 3 min instead of testing at 65% of factory test voltage. There are many types of organisation that benefit from carrying out tests on transformer oil. Transformer and insulating oils are subject to electrical and mechanical stresses while a. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Basics, maintenance, and diagnostics ix contents continued page 6. Supporting client oil condition and predictive maintenance programs, intertek oil tests are performed to astm, iso, iec, ip, inhouse, client, and other industry standards. All large transformers have an oil or a winding temperature indicating device of some type, and most have temperature recorders as well. Oil used in transformer as the insulating material.

The test and assessment of transformers is a complicated task. The american society for testing and materials astm is the standard reference body used by. Mineral oil is the most common insulating fluid and has been in use since the late 19th century. Testing of transformer or insulating oil 1 transformer oil, a type of insulating and cooling oil used in transformers and other electrical equipment, needs to be tested periodically to ensure that it is still fit for purpose. Breakdown voltage bdv testing of transformer oil youtube. The degradation materials produce co and co2 gases. Application notes application note ots vessel preparation. Aug 30, 2019 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. Natural ester dielectric fluid overview envirotemp fr3. Determine the suitability of the insulating oil for future use indicate if a fault exists in the transformer which enables monitoring of. Transformer and insulating oils are subject to electrical and mechanical stresses while a transformer is in operation. We recognise that insulating oil testing is a critical step in the management of transformer assets to maximise operational availability. Apr 29, 2018 so testing of oil is done according to voltage rating.

Regular sampling and testing of insulation oil taken from transformers is a valuable technique in a preventative maintenance pr ogram. Oil analysis for condition monitoring and predictive maintenance. When testing the quality of insulating liquids, you are able to decide, based on the results, whether the insulating effect of transformers makes it possible to. Testing of transformer oil is necessary for the obtain breakdown strength of oil. In this book we have laid down important aspects on transformer. Bdv means breakdown voltage, also named as dielectric strength valve. Transformer oil testing by robert turcotte, manager, electrical loss control the hartford steam boiler inspection and insurance company the value of transformer oil testing transformer oil testing is a proven loss prevention technique which should be a part of any conditionbased predictive maintenance program. The doble laboratory offers a number of package screen tests to suit your testing needs for new and serviceaged insulating liquids. Meggers automatic laboratory oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids. Meggers experience in the design and production of oil test sets also reaches back to the early 20th century, when pioneering equipment was produced by foster transformers, a company that became part of megger group in 1968. Ppt transformer tests powerpoint presentation free to. The international electrical testing association neta is an accredited standards developer for the american national standards institute ansi. When transformer is to be filled or topped off in the field, they must be filled under vacuum according to specific instruction. Identifies various gas ppm levels that are present in transformer insulating oil.

We are equipped to perform a comprehensive set of purchase specification tests, such as those for the doble transformer oil purchase specification tops or astm d 3487 for new mineral oils. The false negative rate predicted from the data is less th an 1% 0. Dissolved gas in oil analysis, screen tests, water content, metalsinoil, and polychlorinated biphenyl pcb content. The transformer oil is used in the transformer for insulation as well as for cooling purpose. So testing of oil is done according to voltage rating. Providing total confidence in the quality and reliability of transformers with interteks. Neta defines the standards by which electrical equipment is deemed safe and reliable. Furan test is used to determine the life of a transformer and condition of transformer oil in transformer oil. Assessing remnant life of transformer based on furan content. The megger guide to insulating oil dielectric breakdown. An oil sample tube and syringe is used to draw, retain and transport the oil sample in the same condition as it is inside a transformer with all fault gases dissolved in it. Oil testing capabilities doble engineering company. Transformer oil from the atmosphere, preventing gas moisture contamination of oil.

Determine the suitability of the insulating oil for future use indicate if a fault exists in the transformer which enables monitoring of the equipment. Moulded test vessels give repeatable results with lock in precision electrode gap setting adjustment wheels. Neta is the leading source of specifications, procedures, testing, and requirements. The oil testers by b2 highvoltage are portable and fully automatic. Dissolved gas analysis guide for transformers filled with. Testing of transformer oil and winding temperature.

For the love of physics walter lewin may 16, 2011 duration. If regularly conducted, oil analysis allows identification of specific fault conditions that may be developing. Testing of power transformers seems like a similar experience. The are distinct advantages of testing and analyzing transformer oil before starting your electric power equipment and during scheduled maintenance events. The different insulating materials have different dielectric strength. While taking sample of oil from transformer, sample bottle should be flushed well by transformer oil and oil in sample bottle should be vented properly so that atmospheric moisture could not ingress in the. Some of the most common tests for transformer oil are. Making a wellinformed choice in equipment for transformer testing is an important step towards ultimately improving transformer life management decisions. Pdf significance of transformer oil testing researchgate.

Testing sequences and procedures are defined by various international standards, many of them set by astm. Ots100af, ots80af and ots60af laboratory oil testers. These tests can be run annually or biannually or, depending. Today, all of meggers oil test set design, development and manufacture is carried out at the companys. Transformer oil purchase specifications developed under the auspices of the doble oil committee march, 2017 composition this specifications covers new insulating oil for general applications for liquidfilled electrical equipment, which are manufactured from mineral crude, which may be either naphthenic, which has a very low naturally. By the furan analysis, we check the condition of paper in transformer oil. Learn what transformer oil is, how to test transformer oil and the different types and properties. Transformer precommissioning tests and afterreceipt checks. Morgan schaffer offers special transformer oil tests that provide a more comprehensive view of your transformer oil condition.

Additional temperaturesensing equipment may be installed to provide alarm and control signals needed to activate automatic cooling systems. Transformer oil, a type of insulating and cooling oil used in transformers and other electrical equipment, needs to be tested periodically to ensure that it is still fit for purpose. An internal fault in a transformer can be discovered earliest using this test method. The acidity of oil in a transformer should never be allowed to exceed 0. Various electrical tests must be performed and their significance and short description are given below.

Transformer oil test methods include astm, bs,and other recognized transformer oil analysis testing procedures. Indication may be for topoil temperature or hotspot temperature. This early warning system can allow management to identify maintenance priorities, plan work assignment schedules, and order necessary parts and materials. Transformer testing has developed considerably over the past years. As a result, the original chemical properties of transformer oil change gradually, often rendering it ineffective for its intended use after some time. Oil testing allows the operator to determine the equipments operating efficiency, conditions and the possibility of future malfunctions. Transformer oil testing by robert turcotte, manager, electrical loss control the hartford steam boiler inspection and insurance company the value of transformer oil testing transformer oil testing is a proven loss prevention technique which should be a part. This guide describes methods of testing and specifications for electrical insulating oils of petroleum origin intended for use in electrical cables, transformers, oil circuit breakers, and other electrical apparatus where the oils are used as insulating, or heat transfer media, or both.

Transformer oil analysis basic introduction by n robinson, wearcheck as blood tests disclose ones state of health, so oil analyses disclose the condition of a transformer. Transformer testing insulating oil testing ots100af, ots80af and ots60af. Transformer oil analysis provides a highly accurate indication of the internal condition of a transformer. After the transformer oil test is completed, the insulation oil is stirred automatically and the test sequence is performed repeatedly. Bdv test is an very important testing procedure for the insulation oils in transformer. Through proper testing, the transformers lifespan is increased, reducing the need to pay for replacement. The insulating material should sustain the voltage up to its dielectric strength. The dielectric breakdown voltage is measured by applying a voltage between two electrodes under the oil. As a result, the original chemical properties of transformer oil change gradually, often rendering it.

If a proactive approach is adopted based on the condition of the transformer oil, the life of the transformer can be extended. Bureau veritas is recognized worldwide as a leader in oil analysis, coolant analysis, fuel analysis, grease analysis, and transformer oil testing. The main physical and chemical properties tested in transformer oil testing methods are the oils dielectric strength, dissipation factor, flashpoint, color, amount of solid particulate matter, water content, gas content and the oils acid number. Trafol guide to transformer oil testing dissolved gas analysis dga fault gas advised action carbon dioxide co2 carbon monoxide co hydrogen h2 methane ch4 ethane c2h6 ethylene c2h4 acetylene c2h2 condition 1 normal. Who needs to perform dielectric breakdown voltage tests. Specific transformer oil test method availability will vary depending upon location. Transformer oil tests dielectric breakdown voltage min value 1mm gap 2mm gap 23 40 28 47 30 50 neutralisation number acidity mg kohg max value 0. Transformer oil analysis bureau veritas commodities. Use our free transformer asset management tool to automatically assess your transformers health. Overheated cellulose, for example, will generate the same quantity and type of gases, whether in beta fluid or mineral oil. Transformer precommissioning tests and afterreceipt. Test the quality of the dielectric oil of your transformers onsite. Oil test laboratories providing testing services transformer and switchgear manufacturers quality control of oil oil companies testing new oil during manufacture 5. Bureau veritas oil analysis, oil sample analysis, oil test.