On Nov 21, 8:05*am, TimR wrote:
It would surprise you to know that many bad connections can be found by listening to the various junctions when a circuit is loaded to maximum capacity just short of tripping the circuit breaker.

Long ago we had a break in an underground line at work. *A whole section of the campus was without power. *The line ran a long distance through a wooded area and was the ancient concentric conductor style. *(shield was conductor, not ground)

We had a specialist come in with something he called a "thumper." *Apparently it is pulsed high voltage DC. *It makes a noise like a gunshot when it arcs over the break, allowing you to locate it.

This time it didn't work. *After a number of pulses it stopped arcing. *The break had welded itself together. *It can't have been much of a connection but it held a few years until the line was scheduled for replacement anyway.

If you weren't able to locate it, how do you know the break had welded
itself together?