Electrical Tester online
October 2008
Stop revenue leakage with a TDR!

Stop revenue leakage with a TDR!

24 November 2008

Dave Moore - Product manager

Illegal extraction of electricity from the supply network is not a major problem in most western countries, although with the current rapid escalation of energy prices, this situation may be set to change!

In developing countries, however, the amount of revenue lost by power utilities through the illegal use of un-metered supplies is enormous. In Ghana, for example, it has been estimated that only around 40% of electricity used is actually paid for!

The favoured method of obtaining “free” electricity is by making an unauthorised connection – usually know as an illegal tap – to the supply network. Setting up these taps on a live network is, of course, a risky business but it seems that there are many who are willing to take those risks.

For the power utilities, finding the taps by conventional methods – essentially visual inspection – is a difficult and time-consuming business. However, time domain reflectometers (TDRs) in the Megger TDR1000 series are providing an effective remedy for this situation. Though nominally intended to locate faults on power cables, the TDRs will also show the locations where connections have been made to the cable, as these appear to the instrument exactly the same as a partial short circuit fault.

Armed with the knowledge of where these connections are, it is straightforward for engineers searching for illegal taps to separate these from the legitimate connections. In addition, the location information provided by the instruments makes iteasy for the engineers to physically find the taps, no matter how well they may have been hidden.

The Megger TDR1000 is particularly well suited to this application as it is an inexpensive and compact
handheld instrument that has been specifically designed to be easy to use, even by those who have little experience with time domain reflectometry. In addition, it can be used on live circuits when used with fused test leads without the need for external filters, so the electricity supply does not need to be cut off while investigations are being carried out.

While it’s unlikely that the use of the TDR1000 will completely eliminate the illegal extraction of electricity from the supply network, it is an invaluable resource for those whose job it is to tackle this problem. And, without doubt, it is making life much more difficult for those who try to use electricity without paying for it!

For mor information click here