Transformer Testing

As a transformer ages, its probability of failure increases. With a proper condition assessment and maintenance program, power transformers can continue to provide reliable service far beyond the average transformer life expectancy. In fact, the use of aggressive asset management strategies is changing the way we view the expected lifespan of large electrical power apparatus, especially transformers. Some of our clients have large power transformers on their systems that have been in service for over 70 years!

Doble Engineering has developed a proprietary method for estimating the remaining service life of a transformer. This method builds upon a comprehensive condition assessment program, and is designed to systematically identify changes in transformer condition. Doble's Condition Assessment solution can reduce the risk of transformer failure and extend the life of your valuable capital assets.

A typical Condition Assessment evaluation includes the following:

  • Review of historical test results and operating conditions
  • Comparison of recent test results versus the historical results for the unit and similar designs in the Doble database
  • Review of design and specifications
  • Site inspection
  • Electrical and mechanical integrity tests of the transformer
  • Electrical insulation quality tests for the paper and oil insulation systems
  • A full battery of oil diagnostics
  • Thermal analysis

We'll get familiar with your system and individual equipment during the preliminary evaluation phase. We'll work with you to determine which transformers are the most critical and develop a strategy to evaluate these units in detail. We'll develop a proposal to meet your overall goals for condition assessment and maximum utilization of your equipment.

For more information, please email


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