Knowledge of the most effective power transformer electrical tests. Chapter 9 electrical system maintenance general all electrical systems require periodic maintenance in addition to nonscheduled maintenance caused by unpredictable events such as storms, accidents, and equipment failure. The purpose of this maintenance manual is to provide guidance on required and recommended maintenance of liquid. This transformer has been manufactured using modern techniques and some of the best available raw materials internationally. If this is going to be used as a spare transformer in standby, it will have to be preserved always in the best conditions. The transformer inspection checklist below covers important checkpoints for routine maintenance. There is a group of maintenance techniques that from an electric point of view and through some field tests are going to allow us to trace the transformer status as. Maintenance can either be time based or condition based, depending on the service strategy selected. Make sure that you clean all the bushings of your electrical transformer with only soft cotton cloth annually.
Always deenergize a transformer and ground its case before entering or working on the transformer. This applies equally to power and distribution transformers used in utility or industry applications. Even though the appearance is fairly good, there are possibilities of dangerous conditions. Disconnect the ac input and isolate the transformer. Your perfect guide for dry type transformers maintenance. Maintenance and repair of medium power transformers wapic, lagos, nigeria, 27.
Standard for an electrical preventive maintenance epm program page 210 andor connectors are used together, examine connections for signs of galvanic action. Through the utilization of various nondestructive testing and measuring techniques, predictive maintenance determines equipment status before a breakdown occurs. Gsb technical guide, transformer bushings english pdf technical description bushing replacements transformer service english pdf leaflet preventive maintenance through inspection and rehabilitation ensuring a long life for your transformer english pdf leaflet oil reclaiming solutions for aged oil english pdf leaflet. Maintenance manual chapter 9 electrical system maintenance. A guide to transformer maintenance by stanley myers, joseph kelly and robert parrish transformer maintenance 1. The fact that a transformer continues to operate satisfactorily in spite of neglect and abuse is a testament to its durability. Drytype electrical transformers dont use insulating liquid but air to cool the system. Since in mounted transformer operation can be present dangerous conditions. 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 video contains checklist of transformer maintenance points as per time intervals.
After years of operation, an oilimmersed transformer reaches its end of life. 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. Insulation resistance of the ct has to be checked on an annual basis. Transformer preventative maintenance involves routine inspection, adjustment, testing, minor fixes, and special handling instructions. Problems with drytype transformers occur when there is moisture in the windings. It has been fully tested before leaving our factory.
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. The transformer is one of the most reliable pieces of electrical distribution equipment. This course is ideal for anyone who is responsible for. A transformer must be mounted so that air can freely circulate all around and through it. Caution read this manual carefully before you receive, install, operate or give maintenance. Nov 17, 2019 a power transformer requires various routine maintenance tasks including measurement and testing of different parameters of the transformer. Remove these connections before reenergizing the transformer. Jun 27, 2018 this webinar will introduce field technicians to the fundamental standards for transformer maintenance and testing. This guide is necessarily generic in nature, so speci. Although the transformer may continue to operate as before, repeat occurrences of such damaging electrical events, or lack of even minimal maintenance can greatly accelerate the even failure of the transformer. 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. The transformer should give you years of trouble free service, provided regular maintenance checks are carried out as prescribed.
We wrote the book 1981 first edition, 2001 second edition on transformer maintenance. Perhaps, the easiest way to explain the reasoning for proper transformer oil maintenance is to compare a transformer to a car. Transformer maintenance, focusing on maintenance of the insulating system in fluid filled transformers. Drytype transformers are manufactured to provide optimum performance for a lifetime of uninterrupted service. Standard for an electrical preventive maintenance epm program. 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. In a shelltype shell form transformer, the steel magnetic circuit core forms a shell surrounding the windings. Transformer maintenance guides, ebooks sdmyers a guide to transformer. Inspect physical and mechanical condition including evidence of moisture and corona. This webinar will introduce field technicians to the fundamental standards for transformer maintenance and testing. Parts of transformer important from maintenance point of view content 4. 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. Preventive and predictive maintenance 700zb00102 42 preventivepredictive maintenance the guiding principle of ppm is the regular and systematic application of engineering knowledge and maintenance attention to equipment and facilities to ensure their proper functionality and to. Maintenance of transformers a detailed checklist electrical4u.
This is the only book published to address the concerns of transformer owners who want to realize the maximum return of their investments. Transformers are designed to have an average sound level below industry sound level limits when tested in. The maintenance routines discussed in this section can be applied to a transformer that has not reached an advanced deterioration stage. After the transformer has been off loaded, a crane is preferred to move the transformer into position. A guide to transformer maintenance fuel cleaning equipment. Maintenance of current transformer a current transformer is a vital part of any equipment installed in an electrical substation for protection purposes as well as for electrical measurement. There are two main types of maintenance of transformer. Reception, installation, operation and maintenance manual. The transformer requires less care compared with other electrical equipment. Users manual operation and maintenance for power transformers.
With predictive devices currently available, it is incumbent upon. Check the resistance of the windings with an ohmmeter. Pdf transformer is a static device which transforms a. Save this instruction sheet for future use of the product. Also, these suggestions are written for the average circumstances under. Basics, maintenance, and diagnostics vii contents continued page 4. A transformer room must have adequate ventilation and should not be used for storage. The degree of maintenance and necessary inspection for its operation depends on. Our expert crews travel across the country to provide oil and electrical testing services, as well as transformer maintenance and repair. Standard for an electrical preventive maintenance epm. Distribution transformers maintenance guide for liquid.
For an extended life and optimal performance of your drytype transformer, maintenance activities are highly recommended on a periodic basis. Pdf power system consists of a number of transformers at substations including poll mounted distribution transformers whose numbers are in. Jan 25, 2018 this video contains checklist of transformer maintenance points as per time intervals. The utility engineer must be familiar with all aspects of maintenance and testing and make use of stateoftheart tools and techniques for evaluating transformer. Preventive maintenance through inspection and rehabilitation. The transformer is a vital apparatus in the electrical equipment in every stage viz. Failure of a transformer in the chain causes interruption in electricity supply and dislocation of all the works. Apply an antioxidant compound to all aluminumto copper connections. Next will be indicated a series of test that can set up this program and that are something like a continuation of validation tests performed when manufacturing the transformer but adapted to field testing. The suggested procedures presented in this course do not pertain to the major overhaul and transformer repair. Pdf guide for transformer maintenance guide for transformer. If low, top with dry oil find whether there is any leak. Power substation services is the nations leader in the installation and servicing of substation transformers. 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.
Bushing replacements preventive maintenance maintenance abb. If a hum is present, the primary is probably working and the secondary is open. Checklist for maintaining drytype electrical transformers. Bushing replacements preventive maintenance maintenance. Distribution transformers maintenance guide for liquid filled. In this post, i will discuss the schedule and overhaul maintenance for a power transformer. Guide for transformer maintenance guide for transformer maintenance. The course provides a foundation for intelligent transformer maintenance, from the basic design and construction, through to life expectancy and extension. Power substation services transformer maintenance services. Ensure that the connectors are properly used and installed in accordance with manufacturers specifications.
Always handle the transformer in the upright position to prevent damage to the core and coil assembly. Transformer installation, operation, and maintenance manual. You will surely get brief idea of transformer maintenance steps. Western will require 40 calendar days to answer correspondence pertaining to each submittal of data or drawings.
If input voltage is present, check for an audible hum. Freehand sketches or skewed scans will not be accepted. Reception, installation, operation and maintenance manual for. The operational life of a transformer begins with commissioning after it is installed in a substation. Installation, operation, and maintenance guide low voltage transformers 4 performing the modifications will be solely liable. Generation, transmission, distribution and utilization of electricity. The templates are intended to harmonize the visual impression of abb documentation. The dielectric coolant shall be listed lessflammable fluid meeting the requirements of national electrical code section 45023 and the requirements of the. The air fans, oil pumps along with other items that are used to cool down a transformer and control circuit must be inspected annually. Nevertheless, many procedures completed during routine maintenance and transformer major overhaul may be the same. Electrical equipment deterioration is normal and equipment failure is inevitable. The failure rate of oilimmersed transformers tend to become high after 15 years of operation. Transformer oil maintenance electric energy online. A power transformer requires various routine maintenance tasks including measurement and testing of different parameters of the transformer.
Oilimmersed transformers preventive maintenance equipment. To ensure transformer availability and meeting its full life. Therefore, you need to pay attention to drytype transformer maintenance regularly. Predictive power transformer maintenance as an effective maintenance system. So you just need to follow this procedure for a power transformer. If your electrical transformer has oil filling bushing, make sure that the oil is filled up to the correct level.
In the event of any doubt, query arises or need for any further information or any irregularity deviation from iec bs is equivalent 1. Power transformer maintenance and acceptance testing on photo. Drytype transformer maintenance checklist napces blog. The design of the transformer shall be such as the dielectric coolant shall be envirotemp fr3 fluid or equal. However, equipment failure can be delayed through appropriate electrical preventive maintenance. Careful attention to the following instructions is recommended for safe and reliable operation. 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. Ventilated style do not place combustible materials on or near transformer or mount transformer closer than 6 inches from any adjacent wall. Therefore, its maintenance must be equal to the transformer in service. Predictive maintenance is the complement of preventive maintenance. Also information about some types of transformers are gathered as well as distribution transformer connections installations.
Modern transformers are designed to closer tolerances than transformers in the past. Dry type transformer maintenance maximize your transformers lifeexpectancy caution. A power transformer is the most costly and essential equipment piece of equipment within an electrical substation. Power transformer maintenance and acceptance testing. The intent of periodic maintenance is to keep the system operating at an acceptable level of service to the public. Maintenance of transformer with basic understanding in. Austin energys substation maintenance power transformer hot oil processing and vacuum filling. Thus, effective, regular maintenance and testing is even more essential to. Failure to follow instructions may result in death or serious injury important. A car requires oil for lubrication while a transformer requires oil for insulation and cooling.
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