• Subscribe to our monthly
  • Magazine
  • Newsletter
  • Digital Issue
  • Click Here

Raising the bar for cable fault finding

Joe Bush, Editor

07/04/2014

Tags: Test & Measurement

Topics: Test & Measurement

Megger’s new digiPHONE+ cable fault pinpointer, featuring the company’s Background Noise Reduction (BNR) technology, enables the rapid discovery of precise locations of faults on buried power cables.

The digiPHONE+ is based on the technique of comparing acoustic and electromagnetic signals that are produced by flashovers at the fault when a surge voltage is applied to the cable. In the past, pinpointers have been limited by the difficulty of distinguishing between the acoustic signal produced by the fault and background noise produced by, for example, passing road traffic and nearby pedestrians.

In the digiPHONE+, Megger’s BNR technology solves this problem by comparing the acoustic signals produced by two successive flashovers, and eliminating all types of noise that are not present in both signals. The result is a clean acoustic signal that relates only to the fault and, therefore, allows its location to be accurately determined.

The new instrument also features a simplified display that continuously shows the user their distance from the fault and the direction to it. The display positively shows when the fault location is reached and, at this point, it indicates the approximate depth of the fault below ground.
Other benefits of the digiPHONE+ include a volume limiter and an Automatic Proximity Mute (APM) system, which mutes the headphones when the operator’s hand approaches the instrument.

Megger
www.megger.com/uk
T: 01304 502 101

Related Articles