Cable Fault Locating: Thumpers, TDR, Pinpointing, etc.

Download this Application PDF

Application Description

Many faults occur throughout the year. How quickly they are found depends on the quality of the equipment used, the methodology, and the skills of the locator. Some faults may be in 5 kV cable close to the surface and easy to find, some maybe in URD 15 kV cable installed in ways making fault locating difficult, and some may be in 35 kV or 69 kV cable requiring higher voltages and higher joule ratings to locate along with a superior acoustical/electro-magnetic listening device. A TDR/Radar unit is usually helpful to pre-locate the fault, saving hours of walking the line and minimizing further damage to the system by limiting the thumping time. If it’s a Network system, don’t be stuck opening and pumping out manholes to listen for the bang. The proper thumper, TDR, and electro-magnetic pin pointing device are essential. 

Make the Best Product Choices

Select wisely without limiting your abilities to find your faults. There are many equipment designs available using various methods to fault find.  Don’t be outgunned by using a mini or suitcase style thumper that lacks the power and voltage needed, or a larger thumper but with limited controls and no hipot/burner, or a thumper with only one output voltage forcing one to thump at excessive voltages, or a battery unit that isn’t charged when you need it, or an impressive looking computer controlled automated thumper operated by an LCD touch screen but can’t be figured out by the operators.

HVI Products & Approaches

HVI thumpers are full-featured designs containing all the tools needed to find most faults fast. You may have to turn a knob and push a button instead of programming on a touch scene, but it’s easy and fast. Our models are shown below and can be seen in greater detail on the CDS Series Thumper home page and other application information offered by HVI.

Complete Cable Care - the VT33: VLF Hipot-Thumper-VLF Cable Burner-TDR in One Package

VT33   The Complete Cable Care for 5 kV –  25 kV systems.  The best tool for VLF cable testing and cable fault locating URD. 

Reasons for the VT33 VLF/Thumper Combination System

  1. If you are going to VLF over voltage test cables,  defects in insulation and/or accessories will fail. You will need a Thumper/TDR.
  2. If you are going to use a cable fault locator to find faults to repair or replace bad cables, you will need a VLF Hipot after to verify the installation integrity of the repairs and adjacent phases.
  3. To use the VT33 thumper mode, with a 0-13 kVdc @ 860 Joule discharge rating, you will need to “burn down” cable faults to arc below ~10 kV. You will need a VLF Burner to rapidly reduce fault arc-over voltages.
  4. To be as efficient and as quick as possible to restore power, you will need a TDR/radar to assist.
  5. For practicality of use and economy of purchase, it should all be in one portable box. Take a look at the VT33 photos and specs.

The VT33 is the ideal NETA, NECA, Utility URD Dept., & Industrial Complete Cable Care tool.