Maintaining transformer reliability requires more than one test or diagnostic method. A recent project at a New England generation plant demonstrated how transformer oil diagnostics, electrical testing, engineering evaluation and experienced field services can work together to identify developing problems and protect critical equipment.
During a planned outage, oil testing performed by MVA indicated that the plant’s 226 MVA generator step-up transformer was internally healthy. However, comprehensive electrical testing performed by Sigma C Power Services, a NETA Accredited Company, revealed significant deterioration in all three high-voltage bushings, an issue routine dissolved gas analysis alone would not have detected.
After the most critical bushing was identified, MVA Services quickly mobilized to complete the high-voltage bushing replacement and fully re-gasket the transformer. The expanded transformer repair scope also included oil processing, a heat run under vacuum, final vacuum filling and post-repair electrical diagnostic testing.
Despite the additional work, MVA completed the entire project within the plant’s scheduled outage window. This coordinated response helped the customer avoid extended downtime and return the transformer to service on schedule.
By combining proactive testing, transformer oil diagnostics, repair planning and rapid field execution, the NETA Accredited Company and MVA helped the customer avoid a potentially catastrophic transformer failure and prolonged unplanned outage. The project reinforces a simple reliability principle: Testing identifies problems. Diagnostics help explain them. Field services solve them.
Read the complete case study in NETAWORLD Journal.