To perform successful underground circuit testing and fault location, AC hipot testing equipment can enhance results and provide continued service by vital circuitry systems. Hipot tests enable early detection of insulation defects so that measures can be taken to repair cabling prior to complete failure. By subjecting cable to high potential test currents, cable damage can be decidedly less using test currents than allowing cable to fail when delivering a true current load.
Previously DC hipot testing was applied for medium circuits because AC testers were typically not very portable. The DC units were more portable and lightweight to make testing a mile of cable at 50 kV quite simple with a system only needing 50W. The AC system, on the other hand, would require between 400 and 500 kVA so test the same amount of cable. Of course, the issue with DC testing is that it causes a considerable amount of stress damage so most users now avoid this test method when examining cable insulation.
Utilizing AC at very low frequencies or VLF hipot tests became accepted as an alternative because it caused significantly less damage and could carry out fault location and detection with more compact and lightweight equipment than ever before. Models developed by High Voltage Inc. proved that VLF testing would be an effective alternative to DC, and subsequently, various systems were released to provide accurate field testing with rugged, compact units.
Protec offers two VLF Hipot models from High Voltage Inc.:the VLF-4022 and VLF-6022. Our affordable rental rates are available on both these systems by calling our Customer Service Support Line at 866-352-5550 or submitting your inquiry online.