Technical library

Technical library

The Megger technical library provides access to a range of additional content and resources such as technical guides, application notes and more. Use the filters to browse specific content (e.g. application notes) or refine your search to a particular electrical application area. 


If you would like to see the content we have available on a particular subject or need to locate some software, simply enter a search below. Please note, you will need to create an account to access some resources.

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    Showing item(s) 11 - 20 of 43 in total
Standardization of Transformer Protection testing using Smart Testing Equipment
Transformers are critical assets of power system network and their adequate protection is a matter of vital importance. Modern protection relays are usually defined as intelligent electronic device (IED) s, and they provide huge flexibility and enhanced protection features to assure correct operation of the equipment. Transformer protection IEDs are equipped with key features such as differential and restricted earth fault (REF) protection along with several other functionalities as per the guidelines of IEEE C37.91. These functions are available with enhanced facilities such that it can incorporate the difference in phase angle based on vector rotation, ratio correction of current transformers used, interposing CT corrections etc… The increase in flexibility of the IED has also increased the complexity of programming it where a trivial error in the configuration will result in unwarranted operation causing loss of power and reduction of equipment life. 
Published: 12 July 2019
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Testing of complicated bus bar protection using smart testing methodologies
In this paper, protection of a complicated bus arrangement with dual bus coupler and bus sectionalizer using low impedance differential protection applicable for very high voltages like 220kV and 400kV is discussed. In many power generation stations, several operational procedures are implemented to utilize the transfer bus as main bus and to facilitate maintenance of circuit breakers and current transformers (in each section) without shutting down the bay(s).
Published: 12 July 2019
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Influence of Circuit Breaker Maintenance Tests on Busbar Differential Protection Scheme
In this paper, different methods of inhibiting the unwarranted operation of busbar protection relay during the CB testing is discussed with appropriate logics. This paper also focuses on providing proper security for bus faults by implementing relay logics to ensure minimal human intervention (prevention of bus bar blocking, throwing of knife switches for CT secondary shorting etc…) and acceptable modifications to the current protection scheme layout. Various methods are recommended that can be incorporated based on the suitability of the respective system condition. The discussed methods are developed in Intelligent Electronic Devices (IED)s using the advanced logics and algorithms. 
Published: 12 July 2019
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Balance aids noise mitigation
Grounding and ground testing are topics and practices most widely recognized by familiar terms and organizations like Fall of Potential Method, 62 Percent Rule, IEEE and NETA standards and practices, and the National Electric Code® (NEC®). These and other significant contributions to the body of knowledge form the foundation of the subject and its implementation in practice.
Published: 13 June 2019
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Noise Control in Ground Testing
Grounding electrodes are typically buried metal objects; rods, interconnected arrays of rods, plates, grids, and various other designs aimed at putting a sufficient amount of metal in contact with the soil so as to safely and efficiently divert unwanted fault currents out of the electrical system and out of the protected facility. Upon construction, there is generally a ground resistance specification that is not to be exceeded. A performance test is run to assure that the system meets spec.
Published: 7 June 2019
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DFR: A New IEEE Guide for Field Test on Power and Distribution Transformers
Since the invention of the transformer, the design, quality and efficiency of this magnificent machine has been improved thanks to the development of electromagnetic materials, computer design algorithms, insulation materials, cooling systems, structural design, etc. Nowadays, a vast number of transformers operate worldwide aiming to provide reliable and safe operation under the most cumbersome environmental and operational conditions.
Published: 15 April 2019
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Diagnostic Test: 1-500 Hz Narrow Band Dielectric Frequency Response
For approximately 25 years, dielectric frequency response (DFR) has been investigated and proven to provide an accurate method of determining both the moisture condition of paper + oil power transformers and bushings. Together with general insulation testing, DFR provides enhanced insulation condition of the transformer under test.DFR testing method is now accepted internationally – as evidenced by its inclusion in the CIGRE TB445 as an accepted method for moisture determination. IEEE is presently in the process of completing a new guide for use of DFR in transformer moisture assessment for both factory and field testing, which should be completed and available by 2019. Instruments like the Megger IDAX300, which was the first commercially available unit to perform this test, is a valuable tool in this determination of moisture content.IDAX300 has included the ability to perform PF tests at frequencies from 1 to 500Hz which can be defined as a narrow frequency band dielectric frequency response test. We are now able to provide a shorter duration DFR test which gives us additional information into the overall insulation condition of the transformer or bushing.This paper illustrated a narrow band DFR test performed on a transformer located in Thailand – EGAT (power utility) and the result was recorded. It is proved that narrow band DFR test can provide a base line for any future testing comparison. We can use both a curve shape and/or a trend change for looking for issues. We no longer need to only rely on the line frequency PF(DF) to detect future issues.
Published: 8 January 2019
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Instantaneous Torque as a Predictive Maintenance Tool for Variable Frequency Drives and Line Operated Motors
Technological advances in on-line testing of motors, diagnostics and motor monitoring have increased substantially over the past few years. Voltage and current signature analyses have improved the quality of predictive maintenance (PdM) compared to what RMS current and voltage measurements or power-factor readings have been able to achieve.
Published: 20 November 2018
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The Importance and Benefits of Portable Testing
A Portable Appliance Tester (PAT) is an instrument that is dedicated solely to the safety testing of portable electrical equipment in accordance with recognized national and local standards. Depending on locale, these standards may have been enacted into law. They may be requirements of specific industries or trade organizations, or just a good idea. In many cases, manufacturers of electrical consumer products who wish to export to foreign markets will be required, sometimes by national law, to assure the products have been safety tested. If testing is performed at time of manufacture, it will save money, aggravation and ill will that could result from having the products fail in the destination country. 
Published: 27 March 2018
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Continuity and Low Resistance Testing
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Times; color: #e12000} p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Times; color: #797979} span.s1 {font: 12.0px Times; color: #797979} No electrical test is simpler...and few more commonly employed…than the continuity test. This simple test is a ubiquitous option on multimeters (DMMs) and insulation testers. It is simple to perform; connect two leads across opposite ends of the test item (IUT), press the test button, and within seconds you have the resistance reading. Low is good, high is bad. It’s so simple and easy that it is readily applied to testing situations that require a more rigorous performance from the test instrument. This article will examine the parameters that determine the separation between the types of instrumentation.
Published: 6 March 2018
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  • Showing item(s) 11 - 20 of 43 in total