The Megger EZ-Thump 4kV (EZT4V3-50T1WK) EZ-Thump Portable Cable Fault Location System is a 4 kV single-stage unit that is an update from the 3 kV EZ-Thump unit. The EZT4V3-50T1WK model includes a custom 50 foot cable, cable termination of 14 mm male MC with hotline clamps, and a permanently attached cart which provides users with a telescope handle and air tires for use on all terrain. Portable, compact, and lightweight, this battery and AC line-operated cable fault location system is specifically designed for fault locating of shielded and unshielded low voltage power cables.

Due to the portable, robust and wet outdoor-capable enclosure, the instrument is ideally suited for all typical fault locating operations on LV cables in industrial applications up to 4 kV, street light fault locating, or fault locating of LV power circuits in the utility industry.

Proof/Insulation Testing and Sheath Testing

Users can perform proof or insulation testing along with sheath testing with the EZ-Thump in order to test the dielectric strength of the cable or sheath insulation. If the test fails, this testing can determine the breakdown voltage. For this purpose, a test voltage up to 4 kV can be applied to the cable under test indicating the resistance value.

Fault Pre-Location

After identifying the type of fault as high resistance or flashover, pre-location of any concentric neutral type LV cable can be determined using ARM. In ARM, the electrical arc from the flashover creates a temporary 'jumper' to the neutral. During this condition, a standard TDR measurement is made into what is basically a short circuit fault providing a negative reflection at the location of the fault. Multi-conductor non-shielded LV cables with the same type of fault can be typically processed in the same way (phase-to-phase or phase-to-neutral).

Faults identified as low resistance or non-flashover type in either shielded or unshielded cables can be pre-located using the TDR method.

Pinpoint Fault Locations

Accurate pinpoint fault location of high resistance faults is achieved using the 'Thunder and Lightning' method whereby the 4 kV single 500J surge generator (thumper) and an acoustic or electromagnetic receiver are used.

Pinpointing of low resistance faults in unshielded cables requires the additional ESG NT Digital Ground/Earth Fault Locator (sold separately) with or without the optional 'A' frame. Accurate location of faults is achieved using the voltage gradient method. When approaching the fault, 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.