What value should temperature-corrected winding-resistance acceptance testing for large air-cooled transformers compare within?

Temperature-corrected winding-resistance acceptance testing for large air-cooled transformers is typically intended to ensure that the resistance measurements fall within an acceptable range to confirm the integrity and performance of the winding insulation.

The value of 1 percent represents a commonly accepted threshold in the industry for these types of transformers. This means that after adjusting for temperature, if the winding resistance measurement varies by more than 1 percent from the expected or baseline value, it could indicate potential issues such as improper connections, deterioration, or other electrical faults.

This 1 percent limit is significant because it provides a balance between allowing for minor manufacturing variances while still maintaining an adequate level of quality assurance. It ensures that the transformer can operate reliably and efficiently in its intended environment, significantly reducing the risk of operational failures.

In contrast, values such as 0.5 percent, 2 percent, or 3 percent would either be too stringent or too lenient for typical acceptance criteria, thereby not aligning with the commonly established industry standards for such testing procedures.