What is DC hipot tester?

For medium to high voltage rotating equipment, DC Hipot tests called Step Voltage or Ramp tests are used to see if the start of an insulation breakdown can be detected as the voltage is raised. If a breakdown is starting the test can be terminated before there is an arc.

The main advantage of the dc test is DC Voltage does not produce harmful discharge as readily occur in AC. It can be applied at higher levels without risk or injuring good insulation. This higher potential can literally “sweep-out” far more local defects.