Power Transformer Insulation Resistance Testing - Watch Instant Video

Training Sessions

The Purpose of Insulation Resistance Testing
Test Equipment
Test Connections
Test Procedures
Evaluating Test Results
Training Sessions

The Purpose of Insulation Resistance Testing – 4 minutes
Describes the function of power transformer insulation and state the purpose of transformer insulation resistance testing. Identifies factors that can change the resistance of transformer insulation.

Test Equipment – 7 minutes
Describes the principle of insulation resistance testing. Identifies and describes the components of a typical megohmmeter. Describes how a typical megohmmeter works.

Test Connections – 6 minutes
Identifies the connections for testing insulation resistance between the high-voltage winding and ground. Identifies the connections for testing insulation resistance between the low-voltage winding and ground. Identifies the connections for testing insulation resistance between the low-voltage winding and the high-voltage winding. Identifies the connections for testing insulation resistance between the transformer core and ground.

Test Procedures – 10 minutes
Describes safety precautions commonly associated with insulation resistance tests. Identifies transformer and environmental conditions that can affect insulation resistance test results. Describes typical preparations for performing an insulation resistance test. Describes a procedure for performing an insulation resistance test on a typical power transformer.

Evaluating Test Results – 9 minutes
Describes three ways the results of insulation resistance tests can be evaluated.