Such a device exists.? Its commonly referred to as a Thumper. Basically
it is a high voltage pulse that causes the fault to break down.? I
rented one on 2 occasions to locate a underground fault in a underground
feeder to a microwave site.? The package also included an ultrasonic
detector that was used to pinpoint the exact location of the fault.?
Once we got close you could actually hear and feel the arc generated by
the thumper.? In both instances we contracted with a HV splicing company
to do the actual repair. There is also a mode called a burn down that
uses a high voltage DC to cause the fault to get bad enough to locate.?
The book that comes with the Thumper lists the various dielectric
constants for the various forms of cables, very similar to the velocity
factor of coax cables.
The actual splice kits have the shrink tubing to splice the power
conductor, the dielectric insulator and the outside jacket called the
semiconductor to prevent a point failure due to corona point discharge.?
Generally you have to use 2 splice kits and a short section of
compatible feeder to make up for the damaged section.
Jack K6YC
