What are the acceptable moisture levels in transformer oil?

Acceptable moisture levels in transformer oil should ideally be below 20 parts per million (ppm) to ensure optimal performance and longevity of the transformer. Levels exceeding 30 ppm can lead to reduced insulation strength and increased risk of failure. Regular testing and maintenance are essential to monitor moisture content, as elevated levels can indicate potential issues such as leaks or contamination, compromising the transformer’s reliability.