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.
Transformer turns ratio test: some unknown facts
Transformer Turns Ratio (TTR) is one of the most common test used to assess the condition of the transformer’s windings and core. It is performed as a part of acceptance and maintenance test procedure to determine any problems due to poor design, assembly, handling, overloading, fault conditions or poor maintenance. TTR results are compared against the nameplate ratings to determine any possible insulation deterioration, shorted turns, core heating or any other winding or core abnormalities.TTR is a simple and easy test to perform that is often taken for granted without fully understanding the principle and basis of the test. In cases when measurements are not within expected limits, it becomes a challenging task to determine the root cause and resolve the problem. This paper will focus on some of the unknown facts associated with the TTR test. The paper covers in detail the effect of applied test voltage, comparative analysis of step up vs step down excitation, different vector configurations, differences between nameplate ratio, voltage ratio and turns ratio, sources of ratio and phase angle errors, comparison of per phase testing vs true three phase testing, extreme tap ratios being out of tolerance for On Load Tap Changers (OLTC), and TTR test correlation with other electrical tests. The paper also provides field test results and case examples to explain the above-mentioned unknown facts.
Published: 28 April 2020
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Megger PQ Firmware for MPQ Series PQ Analysers
Here you will find Firmware to be loaded into the MPQ1000 and MPQ2000 Analysers.
The current update file MPQ_Firmware_1295_OLD_OS.zip contains the update, specific instructions for the MPQ1000 and specific instructions for the MPQ2000.
Download the zip file and directly unzip it to a Clean Thumb drive.
Published: 23 April 2020
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One touch OLTC with the TTRU3
Completing turns ratio tests on all transformer taps can be a cumbersome process. With One Touch OLTC from the TTRU3, anyone can configure and test all taps within a few short minutes.
Published: 22 April 2020
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Remote Operation of the MPQ1000 via Ethernet
We recieve feedback from many of our customers who use power quality (PQ) meters - including utilities, industrial and service providers. They have told us that one of the most important features of a PQ meter is the ability to control the unit and and view data remotely. Having to retrieve a unit from the field in order to download and then analyze the recorded data creates added expenses in time and resources.
Published: 7 April 2020
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S1-1068 Performance at Power Grid Corporation of India in 765 kV charged substation
The Power Grid Corporation of India Limited (PGCIL) is an Indian state-owned company headquartered in Gurugram, North India and engaged mainly in Transmission of Power & transmits about 50% of the total power generated in India on its transmission network. The company owns and operates about 1,61,790 circuit kms of transmission lines at 800/765 kV, 400 kV, 220 kV & 132 kV EHVAC & +500 kV HVDC levels and 248 sub-stations. Also, it has the transformation capacity of about 3,96,825 MVA as on 30th November 2019.
Published: 2 April 2020
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