What color will a transformer turn if it gets too hot?

When a transformer overheats, it is often related to insulation breakdown or excessive heat affecting the materials within. The insulation on a transformer, usually made from materials like paper or various plastics, can undergo thermal degradation when exposed to high temperatures over time. This degradation process often results in the insulation taking on a yellow or brown coloration due to carbonization and other chemical changes.

The shade of yellow or brown indicates that the insulation is experiencing either damage or is nearing the end of its operational life. This color change can serve as a visual warning that the transformer may be operating outside of its safe temperature range, helping operators to identify the need for maintenance or immediate corrective measures. Proper monitoring of transformers for temperature and insulation condition is crucial in preventing catastrophic failures in electrical power systems.