Transformer maintenance a pdh online course for engineers. Operation, maintenance, and field test procedures for. While online diagnostic systems and computerized testing methods are very helpful. China current transformer, voltage transformer, surge.
The core of a transformer is made of iron whereas thewinding which is wrapped over the iron core is made up ofcopper. Testing and diagnostics of power transformers brochure. The main methods employed for speed control of induction motors are as follows. The typical excitation current test data pattern for a threelegged core transformer is two similar current readings and one lower current reading.
The wire itself is usually copper or aluminum, which is known to be a good conductor of the electric current that powers your equipment. It evolved from the simple gonogo verdict into a sophisticated segment within transformer manufacturing. The purpose of this standard work practice swp is to provide guidelines for testing methods for capacitive and inductive. Silsbee contents t page introduction 317 generalprinciples 318 nullmethod 321 deflectionmethod 325 experimentalresults. Transport, installation and commissioning of power.
Routine tests and type tests of transformers electrical4u. Terminal marking of power transformers is determined by ansi standards. The speed of an induction motor is given as n 120fp 1s. It has been a few years since the publication of the first edition of spectro scientifics inservice oil analysis handbook. The described methods are a complement to the standardized control methods i. In this book we have laid down important aspects on transformer. Insulation power factor testing of power transformers. Hipot test is typically used for acceptance testing or after transformer repair testing. Usually consists of a solid copper rod surrounded by porcelain. This is not a commonly used test step voltage test method in this test, the operator applies two or more test voltages in steps.
Transformer oil testing is a proven loss prevention technique that should be a part of any condition based predictive maintenance program. The ac hv test value should not surpass 75% of the factory test value. Following is an approximate sequence for transformer testing. In this paper, various intelligence techniques are used to test. The clock method is used to produce the numerical index of. The values associated with the testing methods shall be in accordance with the applicable table 100. In addition some other tests are also carried out by the consumer at site before commissioning and also periodically. Most commonly used methods of earthing are pipe earthing and plate earthing. This method statement will give a brief steps to be carried out for testing and pre commissioning of transformers.
Testing of power transformers seems like a similar experience. Basics, maintenance, and diagnostics xi contents continued page 9. But if the temperature rise of the transformer is required, then test method. Insulation testers use high test voltages in the kilovolt range. Before attempting to draw the sample identify the type of cooling liquid in the transformer. All the routine tests shall be repeated dielectric test shall be at 75% transformer shall be untanked reactance measured after s. Transformer primary injection testing swp check this is the latest process zone version before use. A basic transformer consists of two coils that are electrically separate and inductive, but are magnetically linked through a path of reluctance. Site testing will be carried out to the mv transformer by the authority approved testing contractor and to be witness by.
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. Insulation resistance test will be conducted to the transformer to ensure that all contacts points are properly insulated. Turnsratio test results should not deviate more than onehalf percent from either the adjacent coils or the calculated ratio. If a very high voltage is required, the transformer is usually build up in stages by cascading. In a shelltype shell form transformer, the steel magnetic circuit core forms a shell surrounding the windings. 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.
Purpose and scope the purpose of this standard work practice swp is to provide guidelines for testing methods for capacitive and inductive voltage transformers. Oct 11, 2015 oscillogram of dynamic shortcircuit test on 3phase 110. Follow instructions in the transformer manual carefully. While online diagnostic systems and computerized testing methods are very helpful, they are not a substitute for sound. Losses of transformersthe transformers are made of 2 types of materials. The purchase, preparation, assembly, operation and maintenance of transformers represent a large expense to the power system. The method can be easily implemented in a protection relay test set 14, in order to facilitate. Power transformer testing the advantage of this method is the simplicity of the test. Electrical safety testing reference guide iso 9001 certified. Audience this tutorial is designed for software testing professionals who would like to understand the testing framework in detail along with its types, methods, and levels.
Testing manual for electrical equipment nahed alhajeri 1and anantha madhavan 2 abstract quality assurance qa refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met. It involves applying the test voltage for a short time 30 or 60 seconds and noting the insulation resistance reading at that moment. The scope include manufacturing, refining, testing, packing and supply of high. The complete guide to electrical insulation testing. It has been updated periodically to reflect new procedures and revoked methods and the current edition includes about 1600 method references. Sp0504 power transformer testing swp pdf file, 110. Optical measurements of the arc movement may be difficult to accomplish without changing the switchgear device. List of testing equipments available with the supplier for final testing of transformer specified and test plant limitation, if any, for the special. Illinois digital environment for access to learning and scholarship repository. Testing power transformers highvoltage transformers are some of the most important and expensive pieces of equipment required for operating a power system. Introduction the procedures stated in this document cover the activities in preliminary tests and inspections, functional performance tests and the commissioning of newly completed installations and existing ones after major alteration.
High voltage testing 149 the high voltage is applied across the device under test by means of a transformer. There are various test required on transformer to conform performance of transformer. This test is similar to tests 1 and 2, but as applied to a three phase transformer for phase identification and phase continuity check. The test connection arrangement is shown in figure 2 c. From the analysis of the equivalent circuit one can determine the electrical parameters. Iec 60076 power transformers parts 1 through 21 ec 600761 ed3. Commission testing methods for protection systems mipsycon. Transformer basicsworking principle,construction,types. Water content measure the water content using karl fisher method. The index includes only epa methods and its primary goal remains as a reference tool to. This course contains specific examples, with practical emphasis on the inspection, testing, and maintenance of power transformers.
Inspect transformer and parts for shipping damage and moisture. The test setup and procedure of the frsl test is the same as for shortcircuit impedanceleakage reactance testing and can be performed simultaneously. Current transformer testing swp check this is the latest process zone version before use. Currentvoltage method of measurement of winding resistance. This action is principally replacing the inductance of the winding with the. The method is based on theory for sequence components applied to threephase power transformers. Many of the details of a complete and effective testing procedure can be. Mar 01, 2020 can we use an megger or multimeter for earth resistivity testing we cannot use megger or mulitimeter for earth resistivity testing. In manual method, lot of time is required to test any type of transformer and risk involved is higher. Transformer installation, operation, and maintenance manual. Bushings with rated voltage u r equal to or higher than 300 kv are routine tested with a dry lightning impulse voltage withstand test, when tested according to iec 607. Transformer installation method statement electrical. You are required to study volume 330, transformer maintenance, published by the unites states department of the interior, bureau of reclamation. The insulation must be just the opposite from a conductor.
Prior to start of terminations this is to ensure that the transformer are in a defect free state. Voltage transformer testing swp page 1 of 19 standard work practice sp0508 ver 7 ergon energy corporation limited abn 50 087 646 062 1. Liquidfilled transformer instruction and maintenance manual. Mainly two types of transformer are done by manufacturer before dispatching the transformer mainly 1 type test of transformer and 2 routine test. Methods of earthing there are several methods of earthing like wire or strip earthing, rod earthing, pipe earthing, plate earthing or earthing through water mains.
A transformer is an electrical apparatus designed to convert alternating current from one voltage to another. When ac hipot tests are used for routine maintenance, the power transformer can be examined at. Data services src provides analysis reports with both astm and dissolved gas results in your preferred format. All data can be downloaded either as adobe pdf or in text format by email for import into the delta x transformer oil. It took me about an hour to disassemble the st84 transformer removing about 36lams. Transformer oil test methods include astm, bs,and other recognized transformer oil analysis testing procedures. Testing of three phase power transformer ijireeice. Operation, maintenance, and field test procedures for protective relays and associated circuits iii acronyms and abbreviations a ampere ac alternating current amp ampere ansi american national standards institute bes bulk electric system carma capital asset and resource management application ccvt coupling capacitor voltage transformers co 2. Transformer protection application guide this guide focuses primarily on application of protective relays for the protection of power transformers, with an emphasis on the most prevalent protection schemes and transformers. Appliance testing 34 motor testing 34 transformer testing 35 electrical component testing 36 examples of high performance testers 37 sentry series testers 37. The core of a transformer is made of iron whereas thewinding which. Introduction this presentation is made by waseem haider under the guidance of pro. C electrical power from one voltage to another voltage keeping the frequency same by. The test is made in line with iec standards or, on request, according to relevant ieee standards.
By means of cascading, the size of the transformer and the insulation bushing. The main principle of operation of a transformer is mutual inductance between two circuits which is linked by a common magnetic flux. Following is an approximate sequence for transformer. Performance requirements and test methods iec 607 insulated bushings for alternating voltages above 1 000 v 20190211 20190212 w. In practice, as you will see in the test methods described below, you read a value that is the apparent resistance a useful value to diagnose troubles, which is what you want to do. A method to reduce transformer inductance when performing dynamic measurements is to shortcircuit the not tested corresponding lv or hv windings. Index to epa test methods was published as epa 9088001. Procedures for drawing transformer oil samples general sampling electrical insulating oil for laboratory analysis requires care to ensure that the sample is representative of the product being sampled. Request that a representative of the carrier be present during the. Any damage should be reported at once and a claim should be placed against the transportation company. This guide provides a general overview of the regulatory framework and approval process and explores the specific manufacturing responsibilities and test procedures associated with electrical safety testing. When the transformer has been moved to the installation site or some other convenient location to permit inspection of the internal assembly for damage in transit, proceed as outlined in internal inspection.
All works prior to testing location to be barricaded and for precautionary safety measure. The turns ratio is approximately equal to the voltage ratio. The vessel, or oil test cell is typically a threeelectrode system which provides guarding against surface leakage. In addition, a power frequency test of the test tap insulation is made on all bushing. Testing and commissioning procedure for electrical installation 1. Electrical routine testing of high voltage bushings.
So for ensuring proper performance of electrical power transformer, voltage and turn ratio test of transformer one of the vital tests. Site testing will be carried out to the mv transformer by the authority approved testing contractor and to be witness by authorities, consultant and contractor. The wire itself is usually copper or aluminum, which is known to. If the input power climbs to the expected value, the primary of the transformer is bad. Setting procedures are only discussed in a general nature in the material to follow. Dielectric strength filter or replace if bdv is less than specified value. But if the temperature rise of the transformer is required, then test method is the most dependable one. Before commencement of any test make sure the surroundings near clear off from any. There are three general modes of transport for power transformers, with the final configuration usually dependent on the. If the input power does not climb to the expected value, then the problem. Pdf transformer is a static device which transforms a. Our original goal was to compile a comprehensive reference book of common inservice oil analysis techniques to help readers understand and choose the right technique and. A tr ansient additional restraint b ased on the dc component was an enhancement to a wellknown harm onic. Transformer testing has developed considerably over the past years.
Operation, maintenance, and field test procedures for protective relays and associated circuits iii acronyms and abbreviations a ampere ac alternating current amp ampere ansi american national standards institute bes bulk electric system carma capital asset and resource management application ccvt coupling capacitor voltage transformers co. A presentation ontransformer testing using dpatt3bi 2. Testing of insulating oil requires a oil test vessel in addition to the power factor test set. Complete tests 1 and 2 for each winding of a threephase transformer individually with the remaining windings kept open. It can be designed to step up or step down voltages and works on the magnetic induction principle. Methods of earth resistance testing part2 electrical. Testings of transformers triggered energise after that was tripped by protection. Test methods timeresistant tests dielectric absorption ratio dar the ratio of 60 seconds30 seconds less than 1 failed 1. Insulation power factor testing of power transformers oleh w.
Page 1 of 9 standard work practice sp0507 ver 5 ergon energy corporation limited abn 50 087 646 062. Transformers should be carefully inspected upon receipt to ensure that no damage has occurred during shipment. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s. These conditions result in a decrease in the surfacetosurface contact area with an associated increase in surfacetosurface contact resistance, ultimately causing excessive heating at the junction. Insulation testers are designed to measure at the opposite end of the resistance by inserting high dc voltage. Specific transformer oil test method availability will vary depending upon location. Before proceding with transformer measurements the test engineer will become familiar with the safety rules of section 2. This tutorial will give you a basic understanding on software testing, its types, methods, levels, and other related terminologies. Iwanusiw, consultant eltel industries, bangalore, india resume this paper discusses the dissipation factor measurements that can be carried out on the insulation of power transformers during routine maintenance procedures. Routine testing of transformer oils and insulating oils on a regular schedule is an accepted industry. This early warning system can allow management to identify maintenance priorities, plan work assignment schedules, and order necessary parts and materials. The grounding conductor shall be ms flat of size 75 mm x 6 mm.
The connection of all the windings in a threephase transformer is indicated by a vector group symbol. Voltage method ct is essentially tested as a voltage transformer by applying voltage to the ct secondary and measuring the primary voltage. Compare bolted connection resistances to values of similar connections. Pdf transformer testing type test and routine test of. Huayi professional current transformer, voltage transformer, capacitor voltage transformer, transformer, surge arrester manufacturers and suppliers in china, providing the best quality transformer made in china with competitive price. There are different methods for measuring of the transformer winding, likewise. Pdf easy method for testing transformer differential relays.
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