Life Loading of Industrial Power Transformers

Industrial power transformers are subjected to variable loads and atmospheric conditions. Taking these variables into account, transformers can be loaded above nameplate rating, for short periods of time and under day-to-day operating conditions, without reducing the transformer life span. Transformers can also be overloaded by a greater amount during emergency conditions but, in this case the transformer life will be shortened by a certain percentage. Different methods used to calculate transformer overloads will be discussed.