L2 TCA course – e-lesson #12 – Visual Examination & Functional Testing

Hosted by: Jon Giesecke / Master's level
In this lesson from the Transformers Academy, the presenter takes the participants through a detailed session on visual examination and functional testing for power transformers. The session emphasizes the importance of thorough inspections, where even the smallest details can have significant consequences. Key topics include safety protocols, the importance of using all senses during inspections, and tools like infrared imaging and ultrasonic devices for diagnostics. Participants learn about issues such as oil leaks, battery conditions, and identifying problems in control cabinets, transformers, and substations. The presenter also explains techniques such as the "flashlight trick" for identifying sulfation in batteries and discusses the importance of proper oil sampling and cooling system checks. The session provides insights into functional testing of cooling systems, the importance of inspecting control cabinets for loose connections, animal damage, and misalignments in disconnects.
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Learn tips and tricks from the experienced professional. Mr. Giesecke shares his knowledge and some photos of findings that you may not ever see at your locations. In his own words: “Relaxed and informative is the style of the day.”
Attend the session to learn more about these details:
- How to approach a visual examination of a substation/transformer site
- What to look for and the hidden signs of trouble that you may not know
- Learn functional tests that you can do during the walk through and learn the valuable flashlight trick for flooded cell batteries
Keywords: grounding, gauges, rust, control cabinets, batteries
About the author

Jon Giesecke
Mr. Giesecke is one of the world’s leading experts in combining technologies used in the in-service inspection of high voltage oil-filled power transformers and substation diagnostics. He has been training personnel worldwide in these methods for over 20 years with great success.
Prior to forming JLG Associates LLC in 2006, Giesecke was employed by EPRI Solutions as a senior project manager in the Substation Predictive Maintenance business area.
As a Senior Project Manager, some of his responsibilities included: the development and implementation of the Substation Predictive Maintenance Program (SPdM) at numerous electric utilities in the U.S. and abroad; Developing and Instructing an EPRI Solutions’ SPdM course; instructed portions of the EPRI Transformer Performance Monitoring and Diagnostics course and the EPRI Substation/Switchyard Predictive Maintenance course; Providing training, services and consulting to evaluate maintenance responsibility and advanced programs applied to switchyard/substation components.