Emergency overloading of air-cooled oil-immersed power transformers by hot-spot temperatures

The paper points out that during the period of the war the need for obtaining maximum transformer overload capacity is very great, particularly under rare emergency conditions. From a thermal standpoint, the amount of overload is limited by the hottest spot in the transformer winding. To obtain accurate data 1. On the actual hot-spot temperature s under rated load conditions 2. On the increase of the hot spot with load under both ultimate moderate overload and heavy short-time overload conditions