There are several methods of hipot testing devices. These are DC, VLF and AC Hipot tests. The average hipot is made up of three parts namely the source of the high voltage, the meter, and the switching matrix. The hipot tester is an important tool to verify the integrity of insulators in high voltage devices.
Hipot testers detect faults on insulators even before they break down which can cause electrical accidents or damage to equipment. A Hipot tester applies a high amount of voltage on the conductor then measures the leakage current flowing through the insulator. A good insulator should have high resistance to current to be able to operate on its rated current. This means that only a very small leakage current should register during the test.
The difference among hipot testers is the type of voltage a tester uses during the procedure. An AC hipot tester uses 50 or 60 Hz AC. A DC hipot tester uses a DC voltage which is usually higher than an AC hipot test, while a VLF hipot tester uses 0.1 Hz AC voltage.