Very Low Frequency (VLF) High Potential Test

Very Low Frequency (VLF) High Potential Test mainly focuses on high voltage cables, but can also be applied to rotating machinery, transformers, arrestors and insulators. The VLF High Potential Test is the only High Potential Test approved for XLPE cables.

A go/no-go (pass/fail) AC stress test is the best means to verify a cable’s integrity.

The lower the frequency, the less current and power needed to test high capacitance loads. The VLF-0.1 Hz AC Hi pot does NOT generate harmful voids in the insulation through treeing.

Every newly installed or repaired cable should be VLF proof tested before re-energizing.