In a transformer, the only moving part is the oscillating magnetic flux in the core. Always deenergize a transformer and ground its case before entering or working on the transformer. Transformer kva rating nema maximum db ratings 09 40 1050 45 51150 50 150 55 301500 60 501700 62 701 64 decibelsunit for measuring the loudness of sound. Water and water saturated oil are both heavier than dry oil and sink to the bottom of any container. A practical transformer is given here with all the parts and their protective devices. Powerfactor or dissipationfactor tipup exceeding 1. Check colour of active agent if silicagel is pink, change by new charge.
Transformer fusing tables for power line construction and maintenance. Reclamation has hundreds of power transformers with voltages as low as 480 volts v and as high as 550 kilovolts kv. Power substation services transformer maintenance services. In this post, i will discuss what is a transformer, its working principle, transformer construction, types of the transformer and transformer testing. Transformer maintenance, focusing on maintenance of the insulating system in fluid filled transformers. General as per sans 100862, mines should have code of practices cop in place to ensure correct selection, installation. Basics, maintenance, and diagnostics vii contents continued page 4. Water content measure the water content using karl fisher method. Megger and power factor windings, bushing and arrestors.
Power transformer maintenance and acceptance testing on photo. Dielectric strength filter or replace if bdv is less than specified value. Oil in transformer check for dielectric strength and water content take suitable action to restore quality of oil. Maintenance schedules are based on abbs decades long experience of manufacturing and maintaining its products. The recommended procedures specified in this chapter do not pertain to the major overhaul and repair of a transformer. Installation, inspection and maintenance of dry type transformers dry type tx 3 of 8 dimako transformers release ver 1 f. Do not place combustible materials on or near transformer or mount transformer closer than 3 inches from any adjacent wall other than the wall the unit is mounted on. The authors gratefully acknowledge the assistance of all who contributed. Pdf guide for transformer maintenance guide for transformer. Purpose this document is to provide guidance to bureau of reclamation reclamation powerplant personnel in maintenance, diagnostics, and testing of transformers and associated. Transformer oil maintenance electric energy online.
As one of the largest power transformer manufacturers in china, tsty electric co. As a result of the owner company, the importance of the machine and the outage possibilities, it is necessary to perform on each transformer a fitted maintenance program with a test protocol previously accorded. Encapsulated style power transformers are 600 volt class units with the transformer sealed with a mix of sand and resin. For batter and smooth operation, these two types of transformer maintenance should perform schedule preventive maintenance for power transformer first of all visual inspection. This 3d animated video discusses the three main types of transformers used in the power engineering industry, their parts and functions. The degree of maintenance and necessary inspection for its operation depends on.
Pdf transformer is a static device which transforms a. The following should be expected on chl power factors. Apart from special test equipment, the most common portable test equipment used in transformer maintenance activities is. For an extended life and optimal performance of your drytype transformer, maintenance activities are highly recommended on a periodic basis. This course is ideal for anyone who is responsible for. The best way of protecting a transformer is to have. Pdf power transformers are important and expensive components in electric energy networks. Turnsratio test results should not deviate more than onehalf percent from either the adjacent coils or the calculated ratio. This article is the first in a series of articles that will help to bring light to the maintenance practices presently applied to power circuit breakers.
Ch and cl powerfactor or dissipationfactor values will vary due to support insulators and bus work utilized on dry transformers. Understanding the value of electrical testing for power. Design operation maintenance of core type oil filled power. The transformer is a common word for an electrical engineer and engineering student. Design operation maintenance of core type oil filled power transformer. You may detect some fittings problem on the transformer body and eliminate the problem. Maintenance can either be time based or condition based, depending on the service strategy selected. Generation, transmission, distribution and utilization of electricity. Maintenance of transformer with basic understanding in. Maintenance of transformers a detailed checklist electrical4u. Report of committee on electrical equipment maintenance. Transformer fusing tables for power line construction and. Maintenance of transformer power transformers maintenance. Failure of a transformer in the chain causes interruption in electricity supply and dislocation of all the.
Tm 5686 power transformer maintenance and acceptance. A power transformer is the most costly and essential equipment piece of equipment within an electrical substation. C electrical power from one voltage to another voltage keeping the frequency same by electromagnetic induction discover the worlds research 16. The degree of maintenance and necessary inspection for its operation depends on its.
Transformer installation, operation, and maintenance manual. The transformer is a vital apparatus in the electrical equipment in every stage viz. Information about fist transformers,general transformer design drytype and cast resin, protection methods are being referred and. Preventive maintenance maintenance transformer service. So you just need to follow this procedure for a power transformer. Transformer installation guidelines these guidelines are provided as a guide to assist in the installation of the transformer but for more indebt installation refer to ansiieee c57. A twostage framework for power transformer asset maintenance management part i. You will surely get brief idea of transformer maintenance steps. Power transformer working principle, construction and.
Guidelines to power transformer type, routine and special. Pdf a procedure for diagnosis and condition based maintenance. Installation, use and maintenance manual eng 3 power sp. The transformer requires less care compared with other electrical equipment. Transformer testing has developed considerably over the past years.
Project report on maintenance of power transformer. Our expert crews travel across the country to provide oil and electrical testing services, as well as transformer maintenance and repair. Skraceni maintenance and repair of medium power transformers. Adding the transformer oil if necessary always check the oil gauges. Transformers convert electric power, to magnetic flux, to electric power in a new form. Important components in power transformer to consider for preventive maintenance. This results in a cost saving to the transformer owner.
Insulation testers megger 3 earthing test equipment. Regular preventive maintenance helps facilitate forward budget planning. Austin energys substation maintenance power transformer hot oil processing and vacuum filling. Power transformer maintenance includes periodic electrical testing of different parameters of the transformer, being common the periodic checking of some key magnitudes such as turns ratio, excitation current, polarization index, insulation resistance, tandelta, winding resistance, short. Project manager strategic commercial department koncar distribution and special transformers inc. We wrote the book 1981 first edition, 2001 second edition on transformer maintenance. Drytype transformer maintenance checklist napces blog.
Check the resistance of the windings with an ohmmeter. Transformer preventative maintenance involves routine inspection, adjustment, testing, minor fixes, and special handling instructions. Schedule procedure periodic visual and thermographic inspections requires fitted ir port check that the ventilation grills are not obstructed by foreign objects or for dust maintenance. The ac hipot test values for voltages up to 69 kv are presented in table 1. Jun 27, 2018 this webinar will introduce field technicians to the fundamental standards for transformer maintenance and testing. Distribution transformers maintenance guide for liquid. The power source was a 25hp steam engine driving an alternator with an output of. The information contained herein may not cover all variations in equipment or provide for all contingencies which might be met in installation, operation and maintenance. Introduction to reclamation transformers transformers rated 500 kilovoltamperes kva and above are considered power transformers. In the fall of 1967 the board of directors of the national fire protection av soeiation authorized the formation of an ad hoe committee on electrical equipment maintenance to determine the need for the development of a suitable document on this subject. Guides for minimizing transformer noise proper installation of the transformer is required since a quiet transformer can develop objectionable sound levels. In this book we have laid down important aspects on transformer. We perform one group on a routine basis known as preventative maintenance, and the second group on an adhoc basis i.
However, many tasks performed during routine maintenance and major overhaul of. A guide to transformer maintenance by stanley myers, joseph kelly and robert parrish transformer maintenance 1. I am going to post a series of articles about the transformer with video. Cables connected at lv cable box, feedin g the load of the connected power system. Any failure to the transformer can extremely affect the whole functioning of the organization. Power transformers and safety how to install, operate and work with high voltage power transformers safely earthing of hv transformers transformer theory electrical values and their definition in a power transformer voltage, current, number of turns, impedance and their interrelation operation of power transformers in a power system. Tests performed on power transformers can be generally classified as follows. Pdf a twostage framework for power transformer asset. The transformer inspection checklist below covers important checkpoints for routine maintenance. There are two main types of maintenance of transformer.
A regular maintenance program allows the transformer oil to be upgraded before sludge created by oxidization occurs. Distribution transformers maintenance guide for liquid filled. There is a brief introduction to the regular maintenance of the transformer in a substation renigunta 22023311 kv. Drainage of transformer sludge, etc, form the conservator.
Failure to follow instructions may result in death or serious injury important. Jan 25, 2018 this video contains checklist of transformer maintenance points as per time intervals. This is the only book published to address the concerns of transformer owners who want to realize the maximum return of their investments. Predictive power transformer maintenance as an effective maintenance system. The time based maintenance is carried out at predetermined intervals of time or on the base of prescribed criteria and aimed at reducing the probability of failure or the working deterioration of the element. Power substation services is the nations leader in the installation and servicing of substation transformers. Installation, use and maintenance manual power full stop. If input voltage is present, check for an audible hum.
C electrical power from one voltage to another voltage keeping the frequency same by. Dry type transformer maintenance maximize your transformers lifeexpectancy caution. Oil samples should, therefore, be allowed to settle for 4 to 6 hours in case of small transformer or drums, and for 10 to 12 hours in case of large transformer. They are designed for indoor or outdoor installations.
It evolved from the simple gonogo verdict into a sophisticated segment within transformer manufacturing. Maintenance instructions for power transformers maintenance schedule sl no inspection frequency items to be inspected to be checked action required if inspection shows unsatisfactory conditions 1 hourly ambient temperature 2 hourly winding temperature ensure that temperature rise is within specified limits. Maintenance and repair of medium power transformers wapic, lagos, nigeria, 27. Information about fist transformers,general transformer design drytype and cast resin, protection methods are being referred and more also included in the specific research document. Power transformer installation, acceptance, and maintenance procedures. The transformers inherent ability to step up voltages and currents can create lethal quantities of electricity. A transformer generally suffers from following types of transformer faultover current due to overloads and external short circuits, terminal faults, winding. Disconnect the ac input and isolate the transformer. Unlike motors and generators, transformers are nearly 100% efficient, operate continuously with no maintenance, and have no moving parts. Nov 17, 2019 a power transformer requires various routine maintenance tasks including measurement and testing of different parameters of the transformer.
Field testing of fluidfilled power transformers, regulators, and reactors. Aug 10, 2017 schedule preventive maintenance for power transformer. Steel itself is a conductor, and changing lines of magnetic flux also induce a voltage and current in this conductor. Models and formulations article pdf available in ieee transactions on power systems 28. J the inductive capabilities of the transformer should also be considered when working on a deenergized unit. A power transformer requires various routine maintenance a power transformer is the most costly and essential equipment piece of equipment within an electrical substation. A preventive maintenance schedule consists of regular inspections and component replacements according to the product specific maintenance schedule. Building a small core is so much easier than it is for a large core, so that the more sophisticated construction does not present such an obstacle in manufacture. A guide to transformer maintenance fuel cleaning equipment. Hence preventive maintenance is always cost effective and time saving. The course provides a foundation for intelligent transformer maintenance, from the basic design and construction, through to life expectancy and extension. In this post, i will discuss the schedule and overhaul maintenance for a power transformer.
Almost all of them, ranging from power ratings from 20 mva to units well above 1,000 mva,and 20 kv to 1,100 kv are tailormade. This project report on maintenance of power transformer project deals majorly with the performance, commissioning and testing of a transformer. Tests during manufacturing, routine tests, type tests, special tests, acceptance tests, site tests, defect analysis identification and tests before maintenance. In literature, various types of maintenance models have been developed to address the problem of power transformer maintenance. A markovian model for power transformer maintenance. Also, the trouble free service of the equipment over its life depends on proper installation, operation, and maintenance. Ansineta mts2015, standard for maintenance testing specifications for electrical power equipment and systems. Users manual operation and maintenance for power transformers. Transformer schedule and overhaul maintenance an electrical. The main purpose of this research is to gather in one paper information about distribution transformers and maintenance practices. If a hum is present, the primary is probably working and the secondary is open. Remove these connections before reenergizing the transformer. For more than a century, power suppliers and industrial companies have relied on siemens for its reliable and efficient power transformers.
Once sludge occurs, the internal parts of the transformer require flushing with hot oil to remove the sediment. Because of the economic motivation, preventive tests and. Consult transformer manufacturers or test equipment. This person will have the power to grant the process owner the authority and responsibility to manage the process from end to end. As such it is desirable to perform various preventative maintenance activities to ensure the transformer maintains a high level of performance and a long functional life. Maintenance of drytype general purpose distribution and power transformers. Feb 18, 2018 nature of transformer faults although an electrical power transformer is a static device, but internal stresses arising from abnormal system conditions, must be taken into consideration. Testing of power transformers seems like a similar experience.
Aldhubaib and salama have developed a reliability centered maintenance and replacement approach to optimize maintenance and replacement to increase the lifetime of power transformers and reduce annual cost 3. Guide to power transformer type and routine tests best transformers. Transformer is the costliest equipment of power system and its proper functioning is vital to system operations. Field testing of a power transformer before putting into service 50mva. Power transformer maintenance includes periodic electrical testing of different parameters of the transformer, being common the periodic checking of some key magnitudes such as turns ratio, excitation current, polarization index, insulation resistance, tandelta, winding resistance, short circuit impedance, etc. It has no moving parts, requires minimal maintenance, and is capable of withstanding overloads, surges, faults, and physical abuse that may damage or. Also, the troublefree service of the equipment over its life depends on proper installation, operation, and maintenance. Power transformer maintenance and acceptance testing. Nov 08, 2015 preventive maintenance of transformers the objective of this section is to outline the recommended work practices that are usually performed for preventive maintenance of transformers.
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