The Purpose of Transformer Turns Ratio Testing – 4 minutes
Explains what a transformer turns ratio is. Describes how the turns ratio of a transformer can be changed. Describes the purpose of transformer turns ratio testing.
Test Equipment – 9 minutes
Explains the principle of turns ratio testing. Identifies the components of a typical turns ratio test set and describes the function of each component.
Test Connections – 6 minutes
Identifies the connections for testing the turns ratio of a delta-wye power transformer.
Test Procedures – 6 minutes
Describes safety precautions commonly observed during turns ratio testing. Describes the procedure for performing a turns ratio test on a power transformer.
Evaluating Test Results – 7 minutes
Describes what the following turns ratio test results indicate about the windings of the transformer under test: High exciting current and low generated voltage, normal exciting current, normal exciting voltage but no null meter needle deflection. Demonstrates how to calculate the expected turns ratio for a transformer. Identifies a typical acceptable turns ratio error.