how to test power transformer windings?

To test power transformer windings, you can perform several key tests. First, use a megohmmeter to check insulation resistance between windings and ground, ensuring it meets manufacturer specifications. Next, conduct a turns ratio test with a transformer turns ratio tester to verify the winding ratios. Additionally, perform a winding resistance test using a low-resistance ohmmeter to check for continuity and detect any shorted turns. Finally, consider insulation power factor testing for further assessment of winding condition.