What is the IEEE guide for loading mineral-oil-immersed power transformers?

The IEEE guide for loading mineral-oil-immersed power transformers is IEEE C57.91. This guide provides methodologies for determining the thermal limits and loading capabilities of mineral-oil-immersed transformers. It outlines factors such as ambient temperature, cooling methods, and load cycles, ensuring that transformers operate within safe thermal limits to maintain reliability and extend service life. Adhering to this guide helps optimize transformer performance under varying load conditions.