Conducting Distribution Transformer Evaluations Using the Total Ownership Cost Method

Many factors can affect the economics of owning a transformer for a particular distribution system. With increasing government interest in transformer losses it is more important than ever to evaluate the losses for distribution transformers. Without evaluation, a particular utility may be losing money on losses by purchasing the lowest cost transformer or spending too much money on high efficiency transformers. Typically a loss evaluated transformer falls somewhere in between those extremes. Transformer A & B design values can be calculated to find the best transformer for each utilities´ distribution system. This paper will explain how to calculate the A & B values using the Total Ownership Cost (TOC) method for evaluating distribution transformers.