The benefits

Not knowing the risk structure of its fleet, a company tends to overspend on the maintenance of its low-risk transformers and under-spend on the high-risk transformer 10. Overspending on low-risk transformers is a “high-risk activity,” as approximately 30 to 50 percent of maintenance actions are unnecessary [6]. But needless maintenance work can be avoided by implementing regular fleet assessments. The use of preventive or predictive maintenance is improving the transformer economy, which has been challenged by the limited maintenance resources associated with utility deregulation. Focusing the personnel and capital resources to the prioritized needs – with the priority based on the condition assessment ranking – can provide improved reliability at a fraction of the cost of traditional time-based maintenance programs.

It is estimated that life extension of five to 15 years can be achieved with properly focused preventive maintenance programs. The economic advantage related to preventive maintenance work and corrective actions can also be expressed in terms of extended life of the transformer assets – this is achieved by eliminating failures that might have occurred due to the lack of timely critical maintenance.