how to do megger test on transformer?

To perform a megger test on 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 (typically 500V or 1000V). Activate the megger and record the insulation resistance readings. A healthy transformer should show resistance values typically above 1 M?. After testing, discharge the windings to avoid electric shock.