We would like to know if a shielded high voltage cable 8000V AC, 3 phases, is "live". Whether there is current flowing or not.
Ideally we design a little device that's strapped around the cable (non contact with conductors) and a light lights up when live. We are also fantasizing of having this sitting on the cable, with no batteries, using somehow a bit of power from the cable.
I must admit that I'm a bit rusty on the electricity fundamentals.
- I do understand that there should be no magnetic field measurable (no current, and all conductors in one cable).
- I presume there is also no electric field measurable outside the shielded cable.
- I was looking up different devices, and was even trying a simple capacitive sensing detector AC voltage testing tool (Klein NCVT-2) (was only rated to sensing 1000V). To no avail.
I wonder if I am overlooking something or if there are other means of sensing the presence of voltage.
ps as a last resort, it would be possible to open up the connector, so we would have access to individual conductors.