The use of the TDR combined with the surge generator (thumper) was a game changer in the industry. Prior to techniques such as "arc reflection" or "Impulse Current" we would basically collect a half dozen of our co-workers and strategically stand along the cable path listening for the thumping sound from the arcing fault. Now if the cable was only a few hundred feet in length the process wasn't that bad but imagine the fun when doing this on a mile or greater feeder cable.
Actually, two conductors in parallel forms a mutual inductance between them (Faraday's Law of Induction). The inductance between two parallel wires is measured by their mutual inductance. The coupling between two wires can be increased by winding them into coils and placing them close together on a common axis, so the magnetic field of one coil passes through the other coil. The self-inductance of two parallel wires is a property that describes the electromotive force caused by the change in current in the wires. en.wikipedia.org/wiki/Inductive_coupling. This is why we ground the metallic shield on medium voltage cables. Otherwise, we would have an induced voltage on the shields.
Very cool!! Thank you for sharing didn't know they utilized HV TDR
Tom!
It’s like a Shermco reunion here!
Very interesting, I have used a TDR for network cabling but its interesting to see the techniques used for power cables
The use of the TDR combined with the surge generator (thumper) was a game changer in the industry. Prior to techniques such as "arc reflection" or "Impulse Current" we would basically collect a half dozen of our co-workers and strategically stand along the cable path listening for the thumping sound from the arcing fault. Now if the cable was only a few hundred feet in length the process wasn't that bad but imagine the fun when doing this on a mile or greater feeder cable.
I was thinking the same thing.. I had used TDR for ethernet but this is amazing!!
Parallel wires does not form inductance. Winding a conductor forms inductance.
Actually, two conductors in parallel forms a mutual inductance between them (Faraday's Law of Induction). The inductance between two parallel wires is measured by their mutual inductance. The coupling between two wires can be increased by winding them into coils and placing them close together on a common axis, so the magnetic field of one coil passes through the other coil. The self-inductance of two parallel wires is a property that describes the electromotive force caused by the change in current in the wires. en.wikipedia.org/wiki/Inductive_coupling. This is why we ground the metallic shield on medium voltage cables. Otherwise, we would have an induced voltage on the shields.