A word from Dr Diego Robalino

Global Industry Director, Utilities - Power Transformer, Megger Group


  • The transformer industry is growing at a fast pace. We cannot ignore the difficulties many utility operators are facing right now due to supply chain issues and price increases of components and materials. In the end, this is directed to the price the end-user pays for a transformer.
  • Therefore, it is even more critical today to accurately assess the condition of the existing transformer fleet within a utility or a specific industry.
  • There are significant changes in the industry leaning towards eco-friendly and more efficient technologies. This involves one of our most important values at Megger – ‘Caring’. We care about the social responsibility of protecting our environment and the people using Megger products. We care about the positive impact of our research and development on the lives of Megger equipment users. We care about our customers and value their time and effort to proactively evaluate the condition of the power system, minimising the risk of failure and unplanned shutdowns and downtimes.


Why test transformers

The rationale for testing transformers is as varied as the types of loads these critical assets serve. In the case of high voltage transformers, their reliability directly impacts the reliability of the grid. A transformer failure can handicap the grid and increase its volatility. Because replacing a high voltage transformer requires planning for many reasons, including long manufacturing lead times that can exceed a full year, it is widely accepted that asset management, particularly of transformers, is a beneficial contribution to the operation of the grid. Megger’s comprehensive set of transformer testing tools provides a complete view of your transformer’s health.

Why buy Megger transformer testers ?

Megger is passionate about and delivers on safety, accuracy, efficiency and usability of our transformer test instruments. We are persistent innovators with a deep understanding of transformers and their testing, striving to provide test solutions without concessions. For example, to satisfy the desire to perform dielectric frequency response (DFR) measurements with historically long test times more quickly, we introduced a multi-frequency FDS method to accomplish this rather than incorporate the less accurate “PDC method” in the test to speed up the measurement time. Our test instruments’ built-in screens are large, sunlight-readable touch displays and our test leads are thoughtfully engineered to eliminate known testing challenges. Attention to details, safety, and ease of use are evident in every product of our extensive transformer test portfolio. Test equipment and solutions are our focus. Helping you confidently supply the world with reliable power is our goal.

Considerations when choosing transformer test equipment

Making a well-informed choice in equipment for transformer testing is an important step towards ultimately improving transformer life management decisions. The test and assessment of transformers is a complicated task. Even with very accurate test equipment, results can give an inaccurate representation of an asset’s health. A transformer test may have particular sensitivities to test preparation, test lead connections, and the test environment. A good example is a power factor/dissipation factor/tan δ (i.e., PF/DF) test. If the test result is not accurately compensated for the temperature at which it was performed, a comparison to previous test results and the application of a standard’s suggested PF/DF “limits” will not be valid. Standards organizations, in fact, have acknowledged that as temperature varies, each transformer behaves uniquely, depending on its condition, and therefore no longer provide PF/DF “temperature correction factor” tables.

Megger’s transformer test sets are engineered and built to go the furthest towards eliminating error in test results so that you have confidence in your test conclusions. This requires more than just building a very accurate measurement tool. For example, to address PF/DF temperature dependency, Megger’s patent-pending ITC technology determines the individual temperature correction (ITC) and provides assurance that the corrected test result provided by the instrument represents the transformer’s precise 20°C equivalent PF/DF each time.

All our transformer products