All EZ-THUMP models are compact and lightweight, battery and AC line operated, portable cable fault location systems. They are designed for quick, effective, accurate and safe fault locating operations to greatly reduce system customer outage minutes.

Due to their rugged yet portable enclosure, they are ideally suited for all typical fault locating operations on MV cable as well as on LV cables.

The 12 kV model can be used as part of a “satellite” fault locating concept for remote areas that may have less frequent faults, when ease of operation, light weight and economics are important, or for hard to access inner-city locations.

The 3 kV and 4 kV units offer a convenient solution for industrial fault locating applications up to 3 or 4 kV, street light fault locating or fault locating in LV power circuits in the utility industry, featuring point-to-point cables.

The units require no adjustments and are operated via a rotary control knob.


  • Compact, lightweight, all-in-one, rugged portable cable fault locating system
  • Battery and AC line operation; field-replaceable battery
  • Automatic cable end, fault location, and sectionalizing (optional in certain markets)
  • Single-stage capacitor surge discharge: 500 J @ 4 kV model; 500 J @ 12 kV model
  • Dual-stage capacitor surge discharge: 500 J @1.5 kV & 3.0 kV @ 3 kV model
  • Up to 94 mA current, depending on voltage
  • F-OHM safety feature to ensure safe grounding
  • HiBrite color display for outdoor visibility
  • TDR LV prelocation of very low resistance faults and cable interruptions
  • ARM® prelocation of high resistance/flashover faults
  • Fault pinpointing, high- and low-resistive fault
  • Sheath testing and sheath fault locating

Pinpoint fault location

Accurate pinpoint fault location of high resistance/flashover faults (either in shielded or unshielded cables) is achieved using the “Thunder & Lightning” method whereby the single or dual stage 500 Joule surge generator (thumper) and an acoustic/electromagnetic receiver are used.

Pinpointing of low resistance faults in unshielded cables requires the additional item ESG NT digital ground/ earth fault locator with optional “A” frame. Accurate location of faults is achieved using the voltage gradient method. As the fault is approached, the voltage gradient potential increases while decreasing with reversed polarity after passing the fault. The change in polarity allows the fault to be located precisely.