OilDataTM

Transformer Oil Analysis and Health Index

Transformer Oil Analysis and Health Indices are an invaluable way to assess the condition and asset management requirements for transformers. Oil analysis provides insight into the condition of the transformer, while the health index combines this condition data with other factors, such as transformer use, age, environmental factors and failure history, to predict the overall condition of the transformer and its proximity to end of life. A Health Index has many benefits for asset managers, as it:

• Maximises the use of available information, including oil analysis results, duty, environmental factors, fault history, age etc
• Identifies transformers that would benefit from life extension measures or require replacement
• Accurately indicates transformer units at risk of failure
• Enables informed asset management decisions
• Determines strategies for both present and future
• Creates a significant step towards a full condition based risk management (CBRM) strategy.

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Health indices combine relevant information about the condition of a transformer, with EA Technology’s extensive experience of similar equipment and a range of other factors, to rank equipment by proximity to end of life. Each asset is ranked on a scale of 0 to 10 for that particular population, 0 representing the best condition and 10 the worst.

Rising health index values represent increasing levels of degradation and probability of failure as follows:

• HI less than 4 - Asset in ‘good’ condition. These assets would be expected to continue to operate satisfactorily for the foreseeable future and don’t require any maintenance.
  
  
• HI 4-7 - Assets in ‘moderate’ condition. These assets are not at immediate risk of failure, but may become increasingly unreliable in the medium term (5-10years). Assets in this condition may benefit from life extension measures, enhanced maintenance and refurbishment.
  
  
• HI greater than 7 - Assets in ‘poor’ condition. These assets are at immediate risk of failure in the short term, and this risk will increase relatively quickly. Replacement is required to prevent unacceptable probability of failure.

The creation of Health Indices facilitates more informed asset management, based on the actual condition of the assets. It increases reliability by avoiding unexpected failures and increases cost-efficiency by targeting maintenance and replacement budgets where they are needed most.