how to use a megger to test a transformer?

To use a megger to test a transformer, first ensure the transformer is de-energized and disconnected from the power supply. Connect the megger leads to the transformer’s windings and ground. Set the megger to the appropriate voltage level, typically between 250V to 1000V, depending on the transformer’s insulation rating. Activate the megger and record the insulation resistance readings. A reading above 1 M? is generally acceptable; lower values may indicate insulation issues. Always follow safety protocols during testing.