The VLF AC Cable hipot tester adopts digital frequency conversion technology, single-chip microcomputer control, with fully automatic voltage boost, buck, measurement, and protection. Its fully electronic design results in compact size and light weight. The large color touch screen display provides clear, intuitive operation and shows output waveforms. The design specifications comply with the national standard "General Technical Conditions of Ultra-low frequency high voltage generator".

• The ultra-low frequency with rated voltage ≤60kV uses a single-link structure (one booster); models >60kV use a series structure (two boosters in series), reducing weight while enhancing load capacity. The two boosters can also function separately for multi-purpose use.
• Current and voltage data are sampled directly from the high voltage side for accurate measurements.
• Intelligent comprehensive protection: automatically calculates overvoltage/overcurrent protection values based on test capacity and voltage, with protection operation time <20ms.
• 150kV high voltage line output ensures safe and reliable operation.
• Closed-loop negative feedback control circuit eliminates capacity rise effect in output.

For VLF hipot testers with rated voltage below 50kV, a single booster is used (single-coupled ultra-low frequency):

For VLF hipot testers with rated voltage above 50kV, two boosters are used in series (series ultra-low frequency):

(1) Connection method for ultra-low frequency withstand voltage test with two-stage booster in series:

(2) Connection method for single-link ultra-low frequency voltage test (below 50kV):

Test voltage and time can be set manually. After setting, voltage rises continuously until reaching set value, then timing begins. Voltage can be adjusted using Fine up/Fine down on screen.