Transformer Online Condition Monitoring (OCM) is often prioritized for high-capacity units on the assumption that greater MVA ratings justify larger investments. However, practical field evidence shows that transformer capacity alone is not a reliable indicator of monitoring value.
Instead, factors such as redundancy configuration, replacement lead time, and process dependency are the primary determinants of risk exposure and financial return.
This paper explores two wind farm cases: a 150 MVA transformer with a cold spare and a 40 MVA transformer without any spare, to illustrate that system context, not size, defines the business case for OCM systems. It further explains how OCM helps in information-driven risk reduction.
