What This Video Covers
A short session on the cables everyone worries about most. HV sits deeper than LV, often beneath it, and there is usually no way to make a direct connection, so the standard toolkit needs adapting. This video covers the adaptations in the order you would use them.
Why HV Is the Hardest Case
In a typical footpath the LV sits above the HV. The shallower cable takes the induced signal and screens the deeper one, so a standard induction sweep finds the LV and misses the HV entirely. Knowing that failure mode is the starting point for everything else in the session.
The Two-Man Parallel Sweep
One operator walks the Genny, the other walks the CAT in parallel, ten metres apart, inducing over the assumed route. The video demonstrates the spacing, why ten metres matters, and what the signal looks like when the cable changes position across the footpath, which is not uncommon.
Blind Induction Sweeps and Joint Orientation
Where there is no plan line to follow, the blind induction sweep works a whole area methodically. The session also covers reading the orientation of joints, and the difference between a 2x1 sweep and the tighter patterns.
Nulling Out the LV
When plans say HV is present but the LV is all you can hear, nulling out puts the LV signal to sleep: the dead zone either side on the Genny display shows it working, and what is left is what was hiding underneath.
Also in the Knowledge Hub
Want this method in your team's hands, not just on their screens? Sygma's CAT and Genny training covers signal application, connection techniques and site practice, delivered on-site, UK-wide.
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